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Research for School Improvement – DepEd Order No. 16, s. 2017 (Research Management Guidelines)
Quiz by RICHARD BAID
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ILLINOIS PROFESSIONAL TEACHING STANDARDS (2013) Standard 1 - Teaching Diverse Students – The competent teacher understands the diverse characteristics and abilities of each student and how individuals develop and learn within the context of their social, economic, cultural, linguistic, and academic experiences. The teacher uses these experiences to create instructional opportunities that maximize student learning. Knowledge Indicators – The competent teacher: 1A) understands the spectrum of student diversity (e.g., race and ethnicity, socioeconomic status, special education, gifted, English language learners (ELL), sexual orientation, gender, gender identity) and the assets that each student brings to learning across the curriculum; 1B) understands how each student constructs knowledge, acquires skills, and develops effective and efficient critical thinking and problem-solving capabilities; 1C) understands how teaching and student learning are influenced by development (physical, social and emotional, cognitive, linguistic), past experiences, talents, prior knowledge, economic circumstances and diversity within the community; 1D) understands the impact of cognitive, emotional, physical, and sensory disabilities on learning and communication pursuant to the Individuals with Disabilities Education Improvement Act (also referred to as “IDEA”) (20 USC 1400 et seq.), its implementing regulations (34 CFR 300; 2006), Article 14 of the School Code [105 ILCS 5/Art.14] and 23 Ill. Adm. Code 226 (Special Education); 1E) understands the impact of linguistic and cultural diversity on learning and communication; 1F) understands his or her personal perspectives and biases and their effects on one’s teaching; and 1G) understands how to identify individual needs and how to locate and access technology, services, and resources to address those needs. Performance Indicators – The competent teacher: 1H) analyzes and uses student information to design instruction that meets the diverse needs of students and leads to ongoing growth and achievement; 1I) stimulates prior knowledge and links new ideas to already familiar ideas and experiences; 1J) differentiates strategies, materials, pace, levels of complexity, and language to introduce concepts and principles so that they are meaningful to students at varying levels of development and to students with diverse learning needs; 1K) facilitates a learning community in which individual differences are respected; and 1L) uses information about students’ individual experiences, families, cultures, and communities to create meaningful learning opportunities and enrich instruction for all students. Standard 2 - Content Area and Pedagogical Knowledge – The competent teacher has in-depth understanding of content area knowledge that includes central concepts, methods of inquiry, structures of the disciplines, and content area literacy. The teacher creates meaningful learning experiences for each student based upon interactions among content area and pedagogical knowledge, and evidence-based practice. Knowledge Indicators – The competent teacher: 2A) understands theories and philosophies of learning and human development as they relate to the range of students in the classroom; 2B) understands major concepts, assumptions, debates, and principles; processes of inquiry; and theories that are central to the disciplines; 2C) understands the cognitive processes associated with various kinds of learning (e.g., critical and creative thinking, problem-structuring and problem-solving, invention, memorization, and recall) 2 and ensures attention to these learning processes so that students can master content standards; 2D) understands the relationship of knowledge within the disciplines to other content areas and to life applications; 2E) understands how diverse student characteristics and abilities affect processes of inquiry and influence patterns of learning; 2F) knows how to access the tools and knowledge related to latest findings (e.g., research, practice, methodologies) and technologies in the disciplines; 2G) understands the theory behind and the process for providing support to promote learning when concepts and skills are first being introduced; and 2H) understands the relationship among language acquisition (first and second), literacy development, and acquisition of academic content and skills. Performance Indicators – The competent teacher: 2I) evaluates teaching resources and materials for appropriateness as related to curricular content and each student’s needs; 2J) uses differing viewpoints, theories, and methods of inquiry in teaching subject matter concepts; 2K) engages students in the processes of critical thinking and inquiry and addresses standards of evidence of the disciplines; 2L) demonstrates fluency in technology systems, uses technology to support instruction and enhance student learning, and designs learning experiences to develop student skills in the application of technology appropriate to the disciplines; 2M) uses a variety of explanations and multiple representations of concepts that capture key ideas to help each student develop conceptual understanding and address common misunderstandings; 2N) facilitates learning experiences that make connections to other content areas and to life experiences; 2O) designs learning experiences and utilizes assistive technology and digital tools to provide access to general curricular content to individuals with disabilities; 2P) adjusts practice to meet the needs of each student in the content areas; and 2Q) applies and adapts an array of content area literacy strategies to make all subject matter accessible to each student. Standard 3 - Planning for Differentiated Instruction – The competent teacher plans and designs instruction based on content area knowledge, diverse student characteristics, student performance data, curriculum goals, and the community context. The teacher plans for ongoing student growth and achievement. Knowledge Indicators – The competent teacher: 3A) understands the Illinois Learning Standards (23 Ill. Adm. Code 1.Appendix D), curriculum development process, content, learning theory, assessment, and student development and knows how to incorporate this knowledge in planning differentiated instruction; 3B) understands how to develop short- and long-range plans, including transition plans, consistent with curriculum goals, student diversity, and learning theory; 3C) understands cultural, linguistic, cognitive, physical, and social and emotional differences, and considers the needs of each student when planning instruction; 3D) understands when and how to adjust plans based on outcome data, as well as student needs, goals, and responses; 3E) understands the appropriate role of technology, including assistive technology, to address student needs, as well as how to incorporate contemporary tools and resources to maximize student learning; 3 3F) understands how to co-plan with other classroom teachers, parents or guardians, paraprofessionals, school specialists, and community representatives to design learning experiences; and 3G) understands how research and data guide instructional planning, delivery, and adaptation. Performance Indicators – The competent teacher: 3H) establishes high expectations for each student’s learning and behavior; 3I) creates short-term and long-term plans to achieve the expectations for student learning; 3J) uses data to plan for differentiated instruction to allow for variations in individual learning needs; 3K) incorporates experiences into instructional practices that relate to a student’s current life experiences and to future life experiences; 3L) creates approaches to learning that are interdisciplinary and that integrate multiple content areas; 3M) develops plans based on student responses and provides for different pathways based on student needs; 3N) accesses and uses a wide range of information and instructional technologies to enhance a student’s ongoing growth and achievement; 3O) when planning instruction, addresses goals and objectives contained in plans developed under Section 504 of the Rehabilitation Act of 1973 (29 USC 794), individualized education programs (IEP) (see 23 Ill. Adm. Code 226 (Special Education)) or individual family service plans (IFSP) (see 23 Ill. Adm. Code 226 and 34 CFR 300.24; 2006); 3P) works with others to adapt and modify instruction to meet individual student needs; and 3Q) develops or selects relevant instructional content, materials, resources, and strategies (e.g., project-based learning) for differentiating instruction. Standard 4 - Learning Environment – The competent teacher structures a safe and healthy learning environment that facilitates cultural and linguistic responsiveness, emotional well-being, self-efficacy, positive social interaction, mutual respect, active engagement, academic risk-taking, self-motivation, and personal goal-setting. Knowledge Indicators – The competent teacher: 4A) understands principles of and strategies for effective classroom and behavior management; 4B) understands how individuals influence groups and how groups function in society; 4C) understands how to help students work cooperatively and productively in groups; 4D) understands factors (e.g., self-efficacy, positive social interaction) that influence motivation and engagement; 4E) knows how to assess the instructional environment to determine how best to meet a student’s individual needs; 4F) understands laws, rules, and ethical considerations regarding behavior intervention planning and behavior management (e.g., bullying, crisis intervention, physical restraint); 4G) knows strategies to implement behavior management and behavior intervention planning to ensure a safe and productive learning environment; and 4H) understands the use of student data (formative and summative) to design and implement behavior management strategies. Performance Indicators – The competent teacher: 4I) creates a safe and healthy environment that maximizes student learning; 4J) creates clear expectations and procedures for communication and behavior and a physical setting conducive to achieving classroom goals; 4K) uses strategies to create a smoothly functioning learning community in which students assume responsibility for themselves and one another, participate in decision-making, work collaboratively and independently, use appropriate technology, and engage in purposeful learning activities; 4 4L) analyzes the classroom environment and makes decisions to enhance cultural and linguistic responsiveness, mutual respect, positive social relationships, student motivation, and classroom engagement; 4M) organizes, allocates, and manages time, materials, technology, and physical space to provide active and equitable engagement of students in productive learning activities; 4N) engages students in and monitors individual and group-learning activities that help them develop the motivation to learn; 4O) uses a variety of effective behavioral management techniques appropriate to the needs of all students that include positive behavior interventions and supports; 4P) modifies the learning environment (including the schedule and physical arrangement) to facilitate appropriate behaviors and learning for students with diverse learning characteristics; and 4Q) analyzes student behavior data to develop and support positive behavior. Standard 5 - Instructional Delivery – The competent teacher differentiates instruction by using a variety of strategies that support critical and creative thinking, problem-solving, and continuous growth and learning. This teacher understands that the classroom is a dynamic environment requiring ongoing modification of instruction to enhance learning for each student. Knowledge Indicators – The competent teacher: 5A) understands the cognitive processes associated with various kinds of learning; 5B) understands principles and techniques, along with advantages and limitations, associated with a wide range of evidence-based instructional practices; 5C) knows how to implement effective differentiated instruction through the use of a wide variety of materials, technologies, and resources; 5D) understands disciplinary and interdisciplinary instructional approaches and how they relate to life and career experiences; 5E) knows techniques for modifying instructional methods, materials, and the environment to facilitate learning for students with diverse learning characteristics; 5F) knows strategies to maximize student attentiveness and engagement; 5G) knows how to evaluate and use student performance data to adjust instruction while teaching; and 5H) understands when and how to adapt or modify instruction based on outcome data, as well as student needs, goals, and responses. Performance Indicators – The competent teacher: 5I) uses multiple teaching strategies, including adjusted pacing and flexible grouping, to engage students in active learning opportunities that promote the development of critical and creative thinking, problem-solving, and performance capabilities; 5J) monitors and adjusts strategies in response to feedback from the student; 5K) varies his or her role in the instructional process as instructor, facilitator, coach, or audience in relation to the content and purposes of instruction and the needs of students; 5L) develops a variety of clear, accurate presentations and representations of concepts, using alternative explanations to assist students’ understanding and presenting diverse perspectives to encourage critical and creative thinking; 5M) uses strategies and techniques for facilitating meaningful inclusion of individuals with a range of abilities and experiences; 5N) uses technology to accomplish differentiated instructional objectives that enhance learning for each student; 5O) models and facilitates effective use of current and emerging digital tools to locate, analyze, evaluate, and use information resources to support research and learning; 5P) uses student data to adapt the curriculum and implement instructional strategies and materials according to the characteristics of each student; 5 5Q) uses effective co-planning and co-teaching techniques to deliver instruction to all students; 5R) maximizes instructional time (e.g., minimizes transitional time); and 5S) implements appropriate evidence-based instructional strategies. Standard 6 - Reading, Writing, and Oral Communication – The competent teacher has foundational knowledge of reading, writing, and oral communication within the content area and recognizes and addresses student reading, writing, and oral communication needs to facilitate the acquisition of content knowledge. Knowledge Indicators – The competent teacher: 6A) understands appropriate and varied instructional approaches used before, during, and after reading, including those that develop word knowledge, vocabulary, comprehension, fluency, and strategy use in the content areas; 6B) understands that the reading process involves the construction of meaning through the interactions of the reader's background knowledge and experiences, the information in the text, and the purpose of the reading situation; 6C) understands communication theory, language development, and the role of language in learning; 6D) understands writing processes and their importance to content learning; 6E) knows and models standard conventions of written and oral communications; 6F) recognizes the relationships among reading, writing, and oral communication and understands how to integrate these components to increase content learning; 6G) understands how to design, select, modify, and evaluate a wide range of materials for the content areas and the reading needs of the student; 6H) understands how to use a variety of formal and informal assessments to recognize and address the reading, writing, and oral communication needs of each student; and 6I) knows appropriate and varied instructional approaches, including those that develop word knowledge, vocabulary, comprehension, fluency, and strategy use in the content areas. Performance Indicators – The competent teacher: 6J) selects, modifies, and uses a wide range of printed, visual, or auditory materials, and online resources appropriate to the content areas and the reading needs and levels of each student (including ELLs, and struggling and advanced readers); 6K) uses assessment data, student work samples, and observations from continuous monitoring of student progress to plan and evaluate effective content area reading, writing, and oral communication instruction; 6L) facilitates the use of appropriate word identification and vocabulary strategies to develop each student’s understanding of content; 6M) teaches fluency strategies to facilitate comprehension of content; 6N) uses modeling, explanation, practice, and feedback to teach students to monitor and apply comprehension strategies independently, appropriate to the content learning; 6O) teaches students to analyze, evaluate, synthesize, and summarize information in single texts and across multiple texts, including electronic resources; 6P) teaches students to develop written text appropriate to the content areas that utilizes organization (e.g., compare/contrast, problem/solution), focus, elaboration, word choice, and standard conventions (e.g., punctuation, grammar); 6Q) integrates reading, writing, and oral communication to engage students in content learning; 6R) works with other teachers and support personnel to design, adjust, and modify instruction to meet students’ reading, writing, and oral communication needs; and 6S) stimulates discussion in the content areas for varied instructional and conversational purposes. Standard 7 - Assessment – The competent teacher understands and uses appropriate formative and summative assessments for determining student needs, monitoring student progress, measuring student 6 growth, and evaluating student outcomes. The teacher makes decisions driven by data about curricular and instructional effectiveness and adjusts practices to meet the needs of each student. Knowledge Indicators – The competent teacher: 7A) understands the purposes, characteristics, and limitations of different types of assessments, including standardized assessments, universal screening, curriculum-based assessment, and progress monitoring tools; 7B) understands that assessment is a means of evaluating how students learn and what they know and are able to do in order to meet the Illinois Learning Standards; 7C) understands measurement theory and assessment-related issues, such as validity, reliability, bias, and appropriate and accurate scoring; 7D) understands current terminology and procedures necessary for the appropriate analysis and interpretation of assessment data; 7E) understands how to select, construct, and use assessment strategies and instruments for diagnosis and evaluation of learning and instruction; 7F) knows research-based assessment strategies appropriate for each student; 7G) understands how to make data-driven decisions using assessment results to adjust practices to meet the needs of each student; 7H) knows legal provisions, rules, and guidelines regarding assessment and assessment accommodations for all student populations; and 7I) knows assessment and progress monitoring techniques to assess the effectiveness of instruction for each student. Performance Indicators – The competent teacher: 7J) uses assessment results to determine student performance levels, identify learning targets, select appropriate research-based instructional strategies, and implement instruction to enhance learning outcomes; 7K) appropriately uses a variety of formal and informal assessments to evaluate the understanding, progress, and performance of an individual student and the class as a whole; 7L) involves students in self-assessment activities to help them become aware of their strengths and needs and encourages them to establish goals for learning; 7M) maintains useful and accurate records of student work and performance; 7N) accurately interprets and clearly communicates aggregate student performance data to students, parents or guardians, colleagues, and the community in a manner that complies with the requirements of the Illinois School Student Records Act [105 ILCS 10], 23 Ill. Adm. Code 375 (Student Records), the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g) and its implementing regulations (34 CFR 99; December 9, 2008); 7O) effectively uses appropriate technologies to conduct assessments, monitor performance, and assess student progress; 7P) collaborates with families and other professionals involved in the assessment of each student; 7Q) uses various types of assessment procedures appropriately, including making accommodations for individual students in specific contexts; and 7R) uses assessment strategies and devices that are nondiscriminatory, and take into consideration the impact of disabilities, methods of communication, cultural background, and primary language on measuring knowledge and performance of students. Standard 8 - Collaborative Relationships – The competent teacher builds and maintains collaborative relationships to foster cognitive, linguistic, physical, and social and emotional development. This teacher works as a team member with professional colleagues, students, parents or guardians, and community members. Knowledge Indicators – The competent teacher: 8A) understands schools as organizations within the larger community context; 7 8B) understands the collaborative process and the skills necessary to initiate and carry out that process; 8C) collaborates with others in the use of data to design and implement effective school interventions that benefit all students; 8D) understands the benefits, barriers, and techniques involved in parent and family collaborations; 8E) understands school- and work-based learning environments and the need for collaboration with all organizations (e.g., businesses, community agencies, nonprofit organizations) to enhance student learning; 8F) understands the importance of participating on collaborative and problem-solving teams to create effective academic and behavioral interventions for all students; 8G) understands the various models of co-teaching and the procedures for implementing them across the curriculum; 8H) understands concerns of families of students with disabilities and knows appropriate strategies to collaborate with students and their families in addressing these concerns; and 8I) understands the roles and the importance of including students with disabilities, as appropriate, and all team members in planning individualized education programs (i.e, IEP, IFSP, Section 504 plan) for students with disabilities. Performance Indicators – The competent teacher: 8J) works with all school personnel (e.g., support staff, teachers, paraprofessionals) to develop learning climates for the school that encourage unity, support a sense of shared purpose, show trust in one another, and value individuals; 8K) participates in collaborative decision-making and problem-solving with colleagues and other professionals to achieve success for all students; 8L) initiates collaboration with others to create opportunities that enhance student learning; 8M) uses digital tools and resources to promote collaborative interactions; 8N) uses effective co-planning and co-teaching techniques to deliver instruction to each student; 8O) collaborates with school personnel in the implementation of appropriate assessment and instruction for designated students; 8P) develops professional relationships with parents and guardians that result in fair and equitable treatment of each student to support growth and learning; 8Q) establishes respectful and productive relationships with parents or guardians and seeks to develop cooperative partnerships to promote student learning and well-being; 8R) uses conflict resolution skills to enhance the effectiveness of collaboration and teamwork; 8S) participates in the design and implementation of individualized instruction for students with special needs (i.e., IEPs, IFSP, transition plans, Section 504 plans), ELLs, and students who are gifted; and 8T) identifies and utilizes community resources to enhance student learning and to provide opportunities for students to explore career opportunities. Standard 9 - Professionalism, Leadership, and Advocacy – The competent teacher is an ethical and reflective practitioner who exhibits professionalism; provides leadership in the learning community; and advocates for students, parents or guardians, and the profession. Knowledge Indicators – The competent teacher: 9A) evaluates best practices and research-based materials against benchmarks within the disciplines; 9B) knows laws and rules (e.g., mandatory reporting, sexual misconduct, corporal punishment) as a foundation for the fair and just treatment of all students and their families in the classroom and school; 9C) understands emergency response procedures as required under the School Safety Drill Act [105 ILCS 128/1], including school safety and crisis intervention protocol, initial response 8 actions (e.g., whether to stay in or evacuate a building), and first response to medical emergencies (e.g., first aid and life-saving techniques); 9D) identifies paths for continuous professional growth and improvement, including the design of a professional growth plan; 9E) is cognizant of his or her emerging and developed leadership skills and the applicability of those skills within a variety of learning communities; 9F) understands the roles of an advocate, the process of advocacy, and its place in combating or promoting certain school district practices affecting students; 9G) understands local and global societal issues and responsibilities in an evolving digital culture; and 9H) understands the importance of modeling appropriate dispositions in the classroom. Performance Indicators – The competent teacher: 9I) models professional behavior that reflects honesty, integrity, personal responsibility, confidentiality, altruism and respect; 9J) maintains accurate records, manages data effectively, and protects the confidentiality of information pertaining to each student and family; 9K) reflects on professional practice and resulting outcomes; engages in self-assessment; and adjusts practices to improve student performance, school goals, and professional growth; 9L) communicates with families, responds to concerns, and contributes to enhanced family participation in student education; 9M) communicates relevant information and ideas effectively to students, parents or guardians, and peers, using a variety of technology and digital-age media and formats; 9N) collaborates with other teachers, students, parents or guardians, specialists, administrators, and community partners to enhance students’ learning and school improvement; 9O) participates in professional development, professional organizations, and learning communities, and engages in peer coaching and mentoring activities to enhance personal growth and development; 9P) uses leadership skills that contribute to individual and collegial growth and development, school improvement, and the advancement of knowledge in the teaching profession; 9Q) proactively serves all students and their families with equity and honor and advocates on their behalf, ensuring the learning and well-being of each child in the classroom; 9R) is aware of and complies with the mandatory reporter provisions of Section 4 of the Abused and Neglected Child Reporting Act [325 ILCS 5/4]; 9S) models digital etiquette and responsible social actions in the use of digital technology; and 9T) models and teaches safe, legal, and ethical use of digital information and technology, including respect for copyright, intellectual property, and the appropriate documentation of sources.WHAT IS SCIENCE? - is a way in which answers related to NATURAL events are proposed. - a way in which people can learn and UNDERSTAND events in the NATURAL WORLD - based on OBSERVABLE EVENTS - a study of the NATURAL WORLD - a method of DISCOVERY and UNDERSTANDING by using a PROBLEM-SOLVING process called the?? - A systematic body of knowledge based on observation and experimentation. FOUR COMMON CHARACTERISTICS OF SCIENCE: 1. It focuses on the NATURAL WORLD. 2. Goes through experiment. 3. Relies on evidence. 4. Passes through the scientific community. WHAT IS TECHNOLOGY? Brian Arthur (2009) defined technology as: 1. a means to fulfill a human purpose 2. assemblage of practices and components 3. a collection of devices and engineering practices available to a culture. SOCIETY ST (Science Technology) would not exist without society. WHAT IS STS? Science and Technology and Society (STS) is the study of how society, politics and culture affect scientific research and technological innovation and how these, in turn affects society, politics and culture. EVENTS IN THE HISTORY OF SCIENCE AND TECHNOLOGY THAT TRANSFORMED THE SOCIETY (IN THE WORLD) ANCIENT PERIOD 3500 BC. - 500 AD EUROPE - use of fire by Homo Erectus CA 750,000 - Stone Headed Spears CA 45,000 - Wooden bow and arrow CA 20,000 - The Minoans build palaces in Crete CA 2,000 THE AMERICAS - The Folsom people living on eastern side of the Rocky Mountain developed sophisticated tools CA 8,000. - Pottery is made in South America CA 6,000 - Olmec sculpture carves figurines and giant human heads. CA 1200 ASIA AND OCEANA - Earliest known clay pots are made in Japan CA 11,000. - Bronze is first made in Thailand CA 4000 - A lunar calendar is developed in China CA 2950 - Chinese doctors begin using acupuncture CA 2500 - The Hindu calendar of 360 days was introduced in India CA 1000 AFRICA AND MIDDLE EAST - Homo erectus uses stone tools CA 1000000 - CA 15000 in Africa, bone harpoons are used for fishing. - Clay tokens are used for record keeping in Mesopotamia CA 7500 - Mesopotamian mathematicians discover the Pythagorean Theorem MEDIEVAL PERIOD CA 500 -1500 - Dark ages because few written records and evidences remained - Scholastic tradition was established by Charlemagne - Vertical windmills, spectacles, mechanical clock, water mills, gothic style were invented - Johannes Gutenberg invented the printing press RENAISSANCE PERIOD 14TH – 17TH CENTURY - Rebirth of revival - Printing with movable type allowed Bible, secular books made in large amount - Nicolas Copernicus presented a heliocentric theory - Galileo Galilei invented telescope INDUSTRIAL REVOLUTION 18TH CENTURY - Skilled workers were set aside because of the machines - Iron production, steam engine and textile flourished - Scottish James Watt improved steam engine Robert Fulton (steam boat) - The following were invented: Light bulb, telephone, first steam powered locomotive 19TH CENTURY - Age of machine and tools - Herman Helmholtz (law of conservation of energy) - James Clark Maxwell (light as electro-magnetic wave) - Henry Becquerel (radioactivity) - Marie and Pierre Curie (radium) - Hans Christian Oersted (electric current near the magnet) - Michael Faraday (magnet produces electricity) - Atomic Theory proposed by John Dalton - Electron discovered by JJ. Thomson - Telegraph developed by Samuel Morse 20TH CENTURY - Communication, transportation, military research were developed - Personal computer was created - Intel developed microprocessor - Apple was introduced by Steve Jobs and Steve Wozniak - Internet was created (ARPANET) - Henry Ford's mass production of cars - Artificial Intelligence was invented SCIENCE, TECHNOLOGY AND SOCIETY (PHILIPPINE HISTORY) Stone Age - Archeological findings show that modern man from Asian mainland first came over land on across narrow channels to live in Batangas and Palawan about 48,000 B.C. - Subsequently they formed settlement in Sulu, Davao, Zamboanga, Samar, Negros, Batangas, Laguna, Rizal, Bulacan and Cagayan. Inventions - They made simple tools and weapons of stone flakes and later developed method of sawing and polishing stones around 40,000 B.C. - By around 3,000 B.C. they were producing adzes ornaments of seashells and pottery. Pottery flourished for the next 2,000 years until they imported Chinese porcelain. Soon they learned to produce copper, bronze, iron, and gold metal tools and ornaments. Iron Age - The Iron Age lasted from the third century B.C. to 11th century A.D. During this period Filipinos were engaged in extraction smelting and refining of iron from ores, until the importation of cast iron from Sarawak and later from China. INVENTIONS AND DISCOVERIES - They learn to weave cotton, make glass ornaments, and cultivate lowland rice and dike fields of terraced fields utilizing spring water in mountain regions. - They also learned to build boats for trading purposes. - Spanish chronicles noted refined plank built warships called caracoa suited for interisland trade raids 10TH CENTURY A.D. - Filipinos from the Butuan were trading with Champa (Vietnam) and those from Ma-I (Mindoro) with China as noted in Chinese records containing several references to the Philippines. These archaeological findings indicated that regular trade relations between the Philippines, China and Vietnam had been well established from the 10th century to the 15th century A.D. TRADING - The People of Ma-I and San-Hsu (Palawan) traded bee wax, cotton, pearls, coconut heart mats, tortoise shell and medicinal betel nuts, panie cloth for porcelain, leads fishnets sinker, colored glass beads, iron pots, iron needles and tin. SOME PRESPANISH FILIPINO SCIENCE AND TECHNOLOGY - Curative values of plants extract use as medicine - Alphabet (Alibata) - Counting Methods - Weights - Measuring system (isang gatang) - Calendar based on the periods of moon - Banaue Rice Terraces SPANISH REGIME Religion the Catholic Church - The latter part of the 16th Century Development of schools: - Colegio de San Ildefonso-Cebu-1595 - Colegio de San Ignacio-Manila-1595 - Colegio De Nuestra Senora del Rosario-Manila 1597 - Colegio De San Jose-Manila-1601 Colegio De San Ildefonso De Cebu - In 1863 the colonial authorities issued a royal degree to reform the existing educational system. In 1871 the school of medicine and pharmacy were opened to UST, after 15 years it had granted the degree Of Licenciado En Medicina to 62 graduates. Medicine - Development of hospitals San Juan Lazaro hospital the oldest in the far east was founded in 1578. Roads and Bridges Among other Spanish contributions: - Arithmetic - Algebra - Geometry - Trigonometry - Physics - Hydrography - Meteorology - Navigation - Pilotage American Period and Post Commonwealth Era - BUREAU OF GOVERNMENT LABORATORIES (1901) - BUREAU OF SCIENCE (1905) - INSTITUTE OF SCIENCE (1946) RA 2067 OTHERWISE KNOWN AS THE “SCIENCE ACT OF 1958”. - This was enacted to integrate, coordinate, and intensify scientific and technological research and development and to foster invention including allocation of funds and other purposes. NATIONAL RESEARCH COUNCIL WAS ESTABLISHED ON DECEMBER 8, 1933. - Its Mandate (Nrcp) Promotes And Supports Fundamental Or Basic Research For The Continuing Total Improvement Of The Research Capability Of Individual Scientists Or Group Of Scientists; Provides Advice On Problems And Issues Of National Interest; Promotes Scientific And Technological Culture To All Sectors Of Society; And Fosters Linkages With Local And International Scientific Organizations For Enhanced Cooperation In The Development And Sharing Of Information NATIONAL RESEARCH COUNCIL WAS ESTABLISHED IN DECEMBER 8, 1933. - Its Mandate (NRCP) promotes and supports fundamental or basic research for the continuing total improvement of the research capability of individual scientists or group of scientists; provides advice on problems and issues of national interest; promotes scientific and technological culture to all sectors of society; and fosters linkages with local and international scientific organizations for enhanced cooperation in the development and sharing of information. It was during the American Period when Science was inclined towards: - Agriculture - Food Processing - Forestry - Medicine - Pharmacy - NursingCan you make a multiple choice of test questions regarding this information given which is Curriculum from Different Points of View There are many definitions of curriculum. Because of this, the concept of curriculum is sometimes characterized as fragmentary, elusive and confusing. However, the numerous definitions indicate dynamism that connotes diverse interpretations of what curriculum is all about. The definitions are influenced by models of thought, pedagogies, political as well as cultural experiences. Let us study some of these definitions. 1. Traditional Points of View of Curriculum In early years of the 20th century, the traditional concepts held of the “curriculum is that it is a body of subjects or subject matter prepaid by the teachers for the student’s to learn”. It was synonymous to the “course of study” and “syllabus” Robert M. Hutchins views curriculum as “permanent studies” where the rules of grammar, reading, rhetoric and logic and mathematics for basic education are emphasized. Basic education should emphasize the 3 Rs and college education should be grounded on liberal education. On the other, Arthur Bestor as an essentialist, believes that the mission of the school should be intellectual training, hence curriculum should focus on the fundamental intellectual disciplines of grammar, literature and writing. It should also include mathematics, science, history and foreign language. The definition leads us to the view of Joseph Schwab that discipline is the sole source of curriculum. Thus in our education system, curriculum is divided into chunks of knowledge we call subject areas in basic education such as English, Mathematics, Science, Social Studies and others. In college, discipline may include humanities, sciences, language and many more. To Phoenix, curriculum should consist entirely of knowledge which comes from various disciplines. Academic discipline became the view of what curriculum is after the cold war and the race to space. Joseph Schwab, a leading curriculum theorist coined the term discipline as a ruling doctrine for curriculum development. Curriculum should consist only of knowledge which comes from disciplines which is the sole source. Thus curriculum can be viewed as a field of study. It is made up of its foundations (philosophical, historical, psychological and social foundations); domains of knowledge as well as its research theories and principles. Curriculum is taken as scholarly and theoretical. It is concerned with broad historical, philosophical and social issues and academics. Most of the traditional ideas view curriculum as written documents or a plan of action in accomplishing goals. 2. Progressive Points of View of Curriculum On the other hand, to a progressivist, a listing of school subjects, syllabi, course of study, and a list of courses or specific discipline do not make a curriculum. These can only be called curriculum if the written materials are actualized by the learner. Broadly speaking, curriculum is defined as the total learning experiences of the individual. This definition is anchored on John Dewey’s definition of experience and education. He believed that reflective thinking is a means that unifies curricular elements. Thought is not derived from action but tested by application. Caswell and Campbell viewed curriculum as “all experiences children have under the guidance of teachers”. This definition is shared by Smith, Stanley and Shores when they defined “curriculum as a sequence of potential experiences set up in the schools for the purpose of disciplining children and youth in group ways of thinking and acting”. Marsh and Willis on the other hand view curriculum as all the “experiences in the classroom which are planned and enacted by the teacher, and also learned by the students”. Points of View on Curriculum Development From the various definitions and concepts presented, it is clear that curriculum is a dynamic process. Development connotes changes which are systematic. A change for the better means any alteration, modification or improvement of existing condition. To produce positive changes, development should be purposeful, planned and progressive. This is how curriculum evolves. Let us look at the two models of curriculum development and concepts of Ralph Tyler and Hilda Taba. Ralph Tyler Model: Four Basic Principles. This is also popularly known as Tyler’s Rationale. He posited four fundamental questions or principles in examining any curriculum in schools. These four fundamental principles are as follows: 1. What educational purposes should the school seek to attain? 2. What educational experiences can be provided that are likely to attain these purposes? 3. How can these educational experiences be effectively organized? 4. How can we determine whether these purposes are being attained or not? In summary, Tyler’s Model show that in curriculum development, the following considerations should be made: (1) Purpose of the school, (2) Educational experiences related to the purposes, (3) Organization of the experiences, and (4) Evaluation of the experiences. On the other hand, Hilda Taba improved on Tyler’s Rationale by making a linear model. She believed that teachers who teach or implement the curriculum should participate in developing it. Her advocacy was commonly called the grassroots approach. She presented seven major steps to her model where teachers could have a major input. These steps are as follows: 1. Diagnosis of learner’s needs and expectations of the larger society. 2. Formulation of learning objectives. 3. Selection of learning content. 4. Organization of learning content. 5. Selection of learning experiences. 6. Organization of learning activities. 7. Determination of what to evaluate and the means of doing it. Thus as you look into curriculum models, the three interacting processes in curriculum development are planning, implementing and evaluating. Types of Curriculum Operating in Schools From the various concepts given, Allan Glatthorn(2000) describes seven types of curriculum operating in the schools. These are (1) Recommended curriculum- proposed by scholars and professional organizations. (2) Written Curriculum- appears in school, district, division or country documents. (3) Taught Curriculum- what teacher’s implement or deliver in the classrooms and schools. (4) Supported Curriculum- resources-textbooks, computers, audio- visual materials which support and help in the implementation of the curriculum. (5) Assessed Curriculum- that which is tested and evaluated. (6) Learned Curriculum- which the students actually learn and what is measured and (7) Hidden Curriculum- the unintended curriculum. 1. Recommended Curriculum- Most of the school curricula are recommended. The curriculum may come from a national agency like the Department of Education, Commission on Higher Education (CHED), Department of Science and Technology (DOST) or any professional organization who has stake in education. For example the Philippine Association for Teacher Education (PAFTE) or the Biology Teacher Association (BIOTA) may recommend a curriculum to be implemented in the elementary or secondary education. 2. Written Curriculum- This includes documents, course of study or syllabi handed down to the schools, districts, division, departments or colleges for implementation. Most of the written curricula are made by curriculum experts with participation of teachers. These were pilot-tested or tried out in sample schools or population. Example of this is the Basic Education Curriculum (BEC). Another example is the written lesson plan of each classroom teacher made up of objectives and planned activities of the teacher. 3. Taught Curriculum- The different planned activities which are put into action in the classroom compose the taught curriculum. These are varied activities that are implemented in order to arrive at the objectives or purposes of the written curriculum. These are used by the learners with the guidance of teachers. Taught curriculum varies according to the learning styles of students and the teaching styles of teachers. 4. Supported Curriculum- In order to have a successful teaching, other than the teacher, there must be materials which should support or help in the implementation of a written curriculum. These refer to the support curriculum that includes material resources such as textbooks, computers, audio-visual materials, laboratory equipment, playgrounds, zoos and other facilities. Support curriculum should enable each learner to achieve real and lifelong learning. 5. Assessed Curriculum- This refers to a tested or evaluated curriculum. At the duration and end of the teaching episodes, series of evaluations are being done by the teachers to determine the extent of teaching or to tell if the students are progressing. This refers to the assessed curriculum. Assessment tools like pencil-and-paper tests, authentic instruments like portfolio are being utilized. 6. Learned Curriculum- This refers the learning outcomes achieved by the students. Learning outcomes are indicated by the results of the tests and changes in behavior which can either be cognitive, affective or psychomotor. 7. Hidden Curriculum- This is the unintended curriculum which is not deliberately planned but may modify behavior or influenced learning outcomes. There are lots of hidden curricula that transpire in the schools. Peer influence, school environment, physical condition, teacher-learner interaction, mood of the teachers and many other factors made up the hidden curriculum. Received: 26 November 2019 Revised: 10 January 2020 Accepted: 19 January 2020 DOI: 10.1111/obr.13005 PEDIATRICS/PHYSIOLOGY Adipokines: A gear shift in puberty Desirée Nieuwenhuis | Natàlia Pujol-Gualdo Amanda J. Kiliaan Department of Anatomy, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Preclinical Imaging Center PRIME, Nijmegen, The Netherlands Correspondence Amanda J. Kiliaan, PhD, Associate Professor, Department of Anatomy, Donders Institute for Brain, Cognition, and Behaviour, Preclinical Imaging Center PRIME, Radboud university medical center, 6500 HB Nijmegen, Geert Grooteplein 21N 6525 EZ Nijmegen, The Netherlands. Email: amanda.kiliaan@radboudumc.nl Funding information Europees Fonds voor Regionale Ontwikkeling (EFRO), Grant/Award Number: BriteN 2016 1 | INTRODUCTION The prevalence of obesity in adolescents and children is increasing in | Ilse A.C. Arnoldussen | Summary In this review, we discuss the role of adipokines in the onset of puberty in children with obesity during adrenarche and gonadarche and provide a clear and detailed overview of the biological processes of two major players, leptin and adiponectin. Adipokines, especially leptin and adiponectin, seem to induce an early onset of puberty in girls and boys with obesity by affecting the hypothalamic-pituitary- gonadal (HPG) axis. Moreover, adipokines and their receptors are expressed in the gonads, suggesting a role in sexual maturation and reproduction. All in all, adipokines may be a clue in understanding mechanisms underlying the onset of puberty in child- hood obesity and puberty onset variability. KEYWORDS adipokines, obesity, puberty 1,2 the age of 5 years were overweight or were with obesity in 2016, and 3 Obesity is defined by an excessive accumulation of white adipose tissue (WAT), and it is often indicated by a body mass index (BMI) 4 above 30. Two main types of adipose tissue were described: WAT and brown adipose tissue (BAT), which differ in morphology and func- 5-7 Ilse A.C. Arnoldussen and Amanda J. Kiliaan contributed equally to this work. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2020 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of World Obesity Federation Obesity Reviews. 2020;21:e13005. wileyonlinelibrary.com/journal/obr 1 of 10 https://doi.org/10.1111/obr.13005 alarming rates. Specifically, worldwide, 41 million children below this number is expected to increase to 70 million in 2025. obesity is associated with various severe health complications, includ- ing increased risk of diabetes mellitus type 2, hypertension, heart dis- eases, and disturbances in sex hormone levels. 5,6 and mitochondria and plays a role in thermogenesis. Adipocytes in tion. BAT consists of adipocytes containing multiple lipid droplets WAT contain only a few mitochondria and a single lipid droplet. Adipose tissue has several functions including the storage of energy, thermogenesis, and the production and secretion of adipokines Generally, two physiological processes, adrenarche and gonadarche, 11,24 Childhood 5,7,8 a key role in puberty onset. Puberty is known as a period through which the body changes physically, being a physiological process resulting in the maturation of children, i.e. they develop sexual characteristics and obtain reproduc- 9,11 Adipokines are involved in a number of physiological processes including blood pressure, metabo- lism, glucose, and vascular homeostasis and may play amongst others 8-10 (hormones, cytokines, and peptides). tive functions. between obesity and puberty,2,12-23 the biological mechanisms under- lying obesity and puberty onset remain unclear. Hereafter, we review in detail the role of adipokines in the onset of puberty in childhood obesity. Although many studies have shown associations 2 | INITIATION OF PUBERTY PHYSIOLOGICAL PROCESSES IN THE interact to regulate the onset of puberty. During adrenarche, the adrenal cortex secretes steroid hormones (including 2 of 10 NIEUWENHUIS ET AL. androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate (DHEAS), androstenedione, and cortisol), insulin-like growth factor, and growth hormone, which contribute to the pubertal insights on new genetic loci (e.g. melanocortin-4 receptor, mitochon- drial carrier 2, and mitogen-activated protein kinase 13) and on sev- eral pathways that regulate the timing of puberty; however, it partly 34 9,24,25 Both adrenarche and gonadarche are involved in the development growth spurt, body odor, skin oiliness, and skeletal maturation. explains puberty timing variation. Thereby, defining the role of 25 adipokines is of importance in elucidating the variability in puberty as the expression of adipokines is sex-specific and is altered with body composition, adiposity, and during growth spurts. Moreover, adipokines and their receptors are expressed in gonads and several brain regions suggesting involvement in the onset of puberty and sex- ual maturation. Lastly, adipokines interfere in processes regulating timing and duration of puberty, for instance in the HPA and HPG axes which are both key players during adrenarche and gonadarche. Involvement of adipokines in the onset of puberty and specifically in individuals with obesity will be further reviewed in the next 2,24 3 | Puberty onset in girls is assessed using different markers, such as thelarche (breast development), menarche (the start of of pubic hair. pituitary-gonadal (HPG) axis is activated,2,26 and several hormones have been identified to participate in the activation of the HPG axis During gonadarche (Figure 1), the hypothalamic- 2,27 Kisspeptin, neurokinin B, and dynorphin are released by specialized including kisspeptin, neurokinin B, dynorphin, leptin, and ghrelin. 28 key regulator of the pulsatile secretion of gonadotropin releasing neurons, the KNDy neurons in the hypothalamus. Kisspeptin is a 29,30 B stimulates, and dynorphin inhibits the release of kisspeptin, which hormone (GnRH) from the hypothalamus. In addition, neurokinin implies that both coordinate a pulsatile release of kisspeptin. 31 Sub- sections. sequently, the activated HPG axis induces the pituitary gland to secrete luteinising hormone (LH) and follicle stimulating hormone (FSH). As a result, gametogenesis occurs, and the gonads will release sex hormones. Consequently, secondary sex characteristics develop including breast development in girls and an increased testicular vol- 2,26,32 is possibly due to differences in levels of body fat, hypothalamic-pitui- THE ONSET OF PUBERTY IN GIRLS ume in boys. The age at puberty onset varies greatly among individuals, which 19 35 menstruation), and pubic hair development. 33 genome-wide association studies have provided important new tary-adrenal (HPA) axis activity, and genetic background. Recent The average age of However, this age differs between cultures and ethnicities, and since 1980, age at menarche is girls at start of menarche is 12.4 years. 36 significantly decreasing. 36-39 F I G U R E 1 Hormonal regulation in the initiation of puberty in boys and girls. The secretion of kisspeptin, neurokinin B, and dynorphin from KNDy neurons initiate the release of gonadotropin releasing hormone (GnRH) from the hypothalamus. This activates the pituitary gland to produce and secrete luteinising hormone (LH) and follicle stimulating hormone (FSH), which in turn stimulate the gonads to produce estrogen and testosterone in girls and boys, respectively 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License NIEUWENHUIS ET AL. 3 of 10 T A B L E 1 Summary of included studies Authors Year Country Study Design Primary Outcome Sex Sample Size (n) Age (y) Data Collection Lian et al21 2019 China Cross-sectional Puberty starts earlier in Chinese Han girls with obesity compared with Chinese Han girls with normal weight. Girls 2996 9-19 2012 and 2013 Biro et al12 Lazzeri et al20 2018 USA 2018 Italy Longitudinal Cross-sectional Body mass index had a greater effect on age at menarche than did race and ethnicity. Girls 946 6-16 2004-2014 Li et al23 2018 China Longitudinal For both, boys and girls, a higher BMI (ie, overweight and obese) is associated with earlier onset of puberty Girls Girls Boys Girls 542 Deng et al22 Flom et al15 2017 China Cross-sectional Increased BMI is associated with early timing spermarche and menarche. Boys Girls Girls 1278258 9-15 2005-2012 He et al24 Holmgren et al17 2017 China 2017 Sweden Cross-sectional Longitudinal Onset of puberty is not related to obesity in boys. Boys Boys Girls Girls 782 7-17 972 929 5839 Kelly et al19 2017 UK 2016 Brazil 2016 USA Longitudinal prospective cohort Higher BMI in girls is associated with the onset of menstruation at an earlier age. 11 10-18 11-17 Barcellos Gemelli et al25 Cross-sectional Longitudinal Excess weight is associated with early age of menarche. Girls 727 2014 2003-2009 Glass et al16 Lee et al26 In girls, but not in boys, greater adiposity is associated with the earlier onset of puberty. Boys Girls 135 Cabrera et al27 Leonibus et al14 2014 USA 2013 Italy Cross-sectional Longitudinal Thelarche occurred earlier than recently reported, while age of menarche remained unchanged. Girls 610 3-17.9 2007 2005-2012 Currie et al13 2012 Europe, USA, Canada Cross-sectional Overweight/obesity during childhood predicts the early onset of puberty in girls. Girls 20410 11, 13, 15 2005-2006 2017 USA Prospective birth cohort Overweight/obese status at the age of 7 ye was associated with increased risk of early menarche 788 From birth to menarche occurred Pregnancies 1959-1966 2016 USA Cross-sectional Boys with overweight enter puberty earlier compared with boys with normal weight or obesity, while puberty starts later in boys with obesity compared with boys with normal weight and overweight. Boys 3872 6-16 2005-2010 Overweight during childhood shows a relation with the early onset of puberty in girls. 6535 4259 695 11 15 5.8-12.2 2009/2010 2013/2014 2014-2017 Higher BMI during childhood is associated with early puberty. 2008 and 2009 2000-2002 Obesity during childhood is related to the earlier onset of puberty. Boys Girls 84 123 71 (Continues) 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 4 of 10 NIEUWENHUIS ET AL. 3.1 | Fat storage For the initiation of puberty, the timing of stimulation and/or inhibi- tion of different hormones is important, and additionally, a certain amount and distribution of body fat is needed in order to start menar- che, which emphasizes the importance of body fat. From an evolution- ary point of view, body fat increases in mammalian females during puberty onset, and it highlights the need to guarantee a healthy preg- 40 women with anorexia nervosa. particularly body fat localized predominantly on the gluteofemoral fat depots, is profoundly associated with start of menarche, more than nancy, offspring, and maternal survival. fat, sex-hormones, and neuroendocrine alterations can evolve in men- strual dysfunction, for instance, in women with severe obesity or in 41-43 44-46 to gluteofemoral fat depots suggesting that leptin may convey infor- amount of total body fat. mation on body fat distribution to the hypothalamus during puberty. An improper level of body Importantly, body fat distribution, Blood leptin levels are strongly related 45 3.2 | HPG axis The HPG axis is activated by the release of kisspeptin resulting in the release of GnRH from the hypothalamus, and LH and FSH from the pituitary gland. In girls, FSH is involved in the development of the folli- cles in the ovaries, and it promotes the secretion of estrogen. LH stim- ulates the production of androgen hormones and induces ovulation 48 9,47 the release of kisspeptin and neurokinin B, and kisspeptin thereby (Figure 1). The secretion of estrogen has an inhibitory effect on inhibits the GnRH release from the hypothalamus. pattern of GnRH is important for the regulation of the menstrual cycle. This roughly 28-day-cycle comprises several phases, including the follicular phase and luteal phase. During the follicular phase, increasing levels of FSH stimulate the maturation of follicles and the production of estrogen from the ovaries. This in turn inhibits the release of FSH from the pituitary gland. A high level of estrogen will induce the production of LH by the pituitary gland, resulting in ovula- tion. The matured follicle secretes progesterone thereby inhibiting the release of GnRH. When the corpus luteum is demolished, there is less 48 3.3 | Adipokines According to results from studies reported in Table 1, girls with obe- sity enter puberty earlier compared with girls with normal higher leptin concentrations inhibit the intake of food and increases inhibition of GnRH. As a consequence, the cycle will start again. whole process, starting from the activated HPG axis, results in the development of the secondary sex characteristics in girls including 9,47 thelarche and menarche. 13,14,16-23,49-51 weight. these girls might be found in the secretion of adipokines. For instance, leptin is positively associated with the amount of body fat. Generally, energy expenditure. 9,52-54 An explanation for the early onset of puberty in The expression This TABLE 1 (Continued) Authors Year Country Study Design Primary Outcome Sample Sex Size (n) Age (y) Data Collection Herman-Giddens et al28 2012 USA Cross-sectional Observed mean ages of beginning genital and pubic hair growth and early testicular volumes were earlier than in past studies, depending on the characteristic and race/ethnicity. Boys 4131 6-16 2005-2010 Sorensen et al29 Aksglaede et al30 2010 2009 Denmark Denmark Cross-sectional/longitudinal Longitudinal Puberty onset at earlier ages was associated with an increased BMI in boys. Boys 1528 5.8-19.9 1991-1993/2006-2008 1930-1969 Juul et al31 Ribeiro et al32 2007 2006 Denmark Portugal Retrospective cohort Cross-sectional Higher BMI is associated with early voice break. 11-15 10-15 1990-1999 Kaplowitz et al18 Abbreviation: BMI, body mass USA Cross-sectional The early onset of puberty in Caucasian girls is likely related to an increased BMI. 5-12 1992-1993 2001 index. The higher BMI in boys and girls at 7 y of age, the earlier they enter puberty. Boys 21 612 Girls 135 223 Boys 463 Boys 382 Girls 437 Girls 10 750 Early sexual maturation in boys and girls is associated with overweight. 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License NIEUWENHUIS ET AL. 5 of 10 Leptin may possibly play a role in adrenarche as its plasma level increases with higher levels of body fat and as it can modulate both girls. 33 ing adrenarche. In coherence, in children with obesity, the androgen These findings suggested that lower reproductive status was associated with higher total adiponectin concentrations and that a higher reproductive status was related to higher HMW adiponectin the HPA and HPG axes. These axes are functionally integrated dur- DHEAS was positively associated with leptin levels. Nevertheless, concentrations in girls. In addition, individuals with obesity often another study showed that enhanced adrenal androgen secretion in girls with premature adrenarche was not explained by leptin or BMI 55 ated with androgen levels in girls ; however, it was not related to levels. and IL-6. TNF-α alters, and IL-6 inhibits the expression of 56 8 In addition, the adipokine adiponectin was negatively associ- 57 differences of adiponectin seem to develop during the progression of 56 adiponectin (Figure 2). Thereby, a low level of total adiponectin and/or high levels of inflammatory cytokines in individuals with obe- sity can promote the onset of puberty. Many more adipokines are secreted by WAT including omentin, 52,65-67 9,36,62,68 adrenarche in girls with Prader-Willi syndrome. Interestingly, sex puberty. adrenarche; however, both are not required factors. Thus, leptin and adiponectin might be able to influence In gonadarche, leptin can stimulate the secretion of kisspeptin, and subsequently activation of the HPG axis, which eventually increases the expression of estrogen and androstenedione in the ova- 58 2,60 65-67 The expression of these ries (Figure 2). Ob gene in WAT, resulting in the synthesis and secretion of leptin. Thus, high levels of leptin promote onset of puberty in girls via secre- tion of kisspeptin, and estrogen stimulates leptin secretion addition- ally. Moreover, adiponectin can affect the HPG axis due to the expression of adiponectin receptors in the hypothalamus, pituitary In return, estrogen stimulates the expression of the 59 gland, and gonads. onset as it inhibits the secretion of kisspeptin and GnRH in the hypo- thalamus and the release of GH and LH in the pituitary gland, and 2,60-62 52,60 63 girls with central precocious puberty (CPP). Moreover, total adiponectin had negative correlations with progression of puberty in girls (defined by Tanner stages), whereas HMW adiponectin had FIGURE 2 Adipokinesaffectingthe initiation of puberty in girls. Leptin stimulates the release of kisspeptin in KNDy neurons, which activates the hypothalamus to produce gonadotropin releasing hormone (GnRH). In response to the release of GnRH, the pituitary gland secretes follicle stimulating hormone (FSH) and luteinising hormone (LH), which stimulates the ovaries to release estrogen resulting in the formation of secondary sex characteristics in girls. Estrogen stimulates the production of leptin. Adiponectin inhibits GnRH release resulting in reduced levels of GnRH and thereby a delayed onset of puberty. TNF- α and IL-6 inhibit the production of adiponectin and therefore stimulate the onset of puberty In detail, adiponectin is a regulator of puberty thereby inhibiting the onset of puberty (Figure 2). with obesity often have low levels of adiponectin. et al. showed that total adiponectin was significantly lower, whereas high molecular weight (HMW) adiponectin was significantly higher in ment. 55 63 develop a chronic low-grade inflammatory state, which can be indi- cated by a high level of circulating inflammatory cytokines like TNF-α 64 Individuals Sitticharoon positive associations with LH levels and the progression of puberty in 63 visfatin, resistin, and chemerin. and visfatin are expressed in the ovaries. adipokines in the ovaries suggests a role within the reproductive sys- tem; however, the exact biological processes have to be examined. Thus, specifically leptin, adiponectin, and inflammatory cytokines pro- duced by WAT could be permissive key players during an early onset of puberty in girls with obesity. As an exception, HMW adiponectin seems to have a stimulatory effect on peripheral repro- ductive function as HMW is not able to cross the blood brain 63 barrier. 4 | Markers that are used to assess puberty onset in boys are THE ONSET OF PUBERTY IN BOYS spermarche, voice break, testicular volume, and pubic hair develop- 35 spermarche develop in the early stages of puberty onset, voice In women, omentin, chemerin, While pubic hair development, larger testicular volume, and 69 testicular volume increases, which occurs at an average age of break usually appears in later stages of puberty. Generally, first 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 6 of 10 NIEUWENHUIS ET AL. 11.9 years, followed by the development of pubic hair at 12.2 years of average, and lastly, boys experience spermarche around an aver- 55 related with leptin levels. Thereby, leptin plausibly has a minor impact in adrenarche in boys. Since leptin receptors are found in the hypothalamus, pituitary gland, and testes, they might be involved in the onset of puberty by affecting the HPG axis during gonadarche. Leptin stimulates the release of kisspeptin and GnRH, and as a consequence, it accelerates the onset of puberty (Table 1, Figure 3). In contrast, adiponectin inhibits the secretion of GnRH, GH, LH, and FSH therewith delaying the onset of puberty. However, adiponectin levels are generally lower in men compared with women and even lower in men with obe- age age of 13.4 years. 70 4.1 | Fat storage Many aspects of the reproductive physiology are energetically demanding,71 and therefore, an adequate energy level is necessary. In boys, a dynamic change in body composition occurs around the age of 10 to 13 years, in which they gain approximately 40% of sity. culating inflammatory cytokines. levels can stimulate the HPG axis and therewith an early onset of puberty in boys. Nevertheless, leptin can inhibit the production of tes- 72 mostly consisting of lean mass, which causes exhaustion of most of fat. Subsequently, a growth spurt follows in which they gain tissue 72 in boys, an adequate amount of body fat is important in the onset of their body fat. These alterations in amount of body fat indicate that 4.2 | Puberty in boys is initiated by the release of kisspeptin. As mentioned before, this activates the HPG axis, resulting in the release of GnRH from the hypothalamus, and consequently the release of LH and FSH 9,74 puberty. tosterone from the testes, to estrogen (Figure 3). of the development of secondary sex characteristics in boys. Additionally, leptin can affect fertility in men as it can modulate the nutritional support of spermatogenesis, and moreover, dysfunction of spermatogenesis is associated with an increased leptin level and 73 58 2,60-62 HPG axis from the pituitary gland (Figure 1). and LH stimulates the secretion of testosterone from the testes, which inhibits the release of kisspeptin from the KNDy neurons and 9,48 in men, the release of kisspeptin is more consistent, causing a con- 29,48 subsequently GnRH from the hypothalamus. receptors expressed on KNDy neurons. In humans, KNDy neurons Contrarily to women, LH-induced testosterone levels lead to the stant release of LH. development of secondary sex characteristics in boys. differences between sexes in kisspeptin release are related to a sex- specific and sex steroid-dependent kisspeptin system as estrogen and progesterone modulate kisspeptin activity through the sex-steroid 48 in the infundibular nucleus are involved in negative and positive sex- 48 tal exposure to sex steroids and result in sex-specific differences in steroid feedbacks. kisspeptin release. These sexual dimorphisms are induced by perina- 75,76 4.3 | Adipokines The association between obesity and puberty onset in boys is rather controversial compared with findings in girls. Most studies reported an early onset of puberty in boys associated with increased ate adipose tissue from actual breast tissue. stages are more difficult to assess than female stages as boys lack a more determined marker such as menarche. Thirdly, puberty onset can be indicated by the activation of the HPG axis, and the presence of these secondary sex characteristics is the result of hormonal 2 14,17,22,23,50,51,77,78 BMI, 20,49 all while others reported no associations at Current markers used 79 16,80 or a delayed onset of puberty (Table 1). The presence of excessive adipose tissue can be involved in puberty onset in boys as the secretion of adipokines can modulate both adrenarche and gonadarche. Leptin can affect adrenarche by modulating both the HPG and HPA axes,33 and moreover, androgen levels were positively 55 nal androgen secretion in boys with premature adrenarche was not associated with plasma leptin levels. Nevertheless, enhanced adre- 9 In more detail, 61,62 adiponectin, and individuals with obesity often have high levels of cir- Moreover, inflammatory cytokines, TNF-α, and IL-6, inhibit expression of the leptin receptor in the testis. FSH induces spermatogenesis, too. function and role still have to be examined. 64 High leptin and low adiponectin and fat tissue can convert testosterone Both processes might result in the delay 29,61,79 81,82 In men, other adipokines like chemerin are found in the gonads 65 Thus, particularly high leptin and low adiponectin levels stimulate the HPG axis and thereby accelerate the onset of puberty in boys. Additionally, leptin can dysregulate the development of secondary sex characteristics and spermatogenesis by affecting testosterone levels and nutritional sup- port of spermatogenesis. 5 | LIMITATIONS AND FUTURE RESEARCH DIRECTIONS Even though multiple epidemiological studies have shown the link between puberty onset and obesity, there are some important limita- tions. Firstly, determining both the onset and stage of puberty is rather difficult. For instance, assessing the stage of breast develop- ment in girls with obesity is complicated as clinicians should differenti- 2 changes in response to the activated HPG axis. to determine the onset of puberty refer to secondary sex characteris- tics, such as testicular volume in boys and breast development in girls. A more accurate measurement of puberty onset would be to combine secondary sex characteristics with plasma or serum hormone level measurements such as LH, FSH, adipokines, e.g. leptin. Thereby, differences in puberty measurements could explain variations in the age of puberty onset between boys and girls within different Thereby, resistin is expressed in the testes of rats, but its exact 83 Secondly, male pubertal 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License NIEUWENHUIS ET AL. 7 of 10 FIGURE 3 Adipokines affecting the initiation of puberty in boys. Leptin activates kisspeptin secretion in KNDy neurons, this activates the production of gonadotropin releasing hormone (GnRH) from the hypothalamus. GnRH stimulates the pituitary gland to secrete follicle stimulating hormone (FSH) and luteinising hormone (LH), activating the production of testosterone from the testes allowing the development of secondary sex characteristics. Leptin also inhibits the production of testosterone, which may cause a delayed onset of puberty. Adiponectin inhibits GnRH release. Low levels of adiponectin, as a result of TNF-α and IL-6 expression, lead to a reduced inhibition of GnRH. In response to GnRH release, the pituitary gland will secrete FSH and LH, and the testes will produce testosterone resulting in the development of secondary sex characteristics in boys countries, and In addition, the inclusion of a of puberty. ferent time points is complicated, as subjects examined several decades ago presented pronounced differences concerning lifestyle patterns such as nutrition and exercise habits. Lastly, obesity or over- weight is often determined by BMI, a classification based on weight and height measurements. Additionally, it is important that all studies studies or across continents, ethnicities proper age range (8-16 years) is important when assessing the onset (Figure 4). 12-15,17,20-23,49,77-79,84,85 30,47 Furthermore, comparison between studies from dif- 86 Specifically in children, BMI is often dependent on age and growth use the same anthropometric standards and sex-specific cut-offs. 13,14,16-23,49-51,77-80 fat and would represent a more accurate measurement in its regard. Based on this review, several suggestions can be made for further research. Firstly, the roles of adipokines like resistin, chemerin, visfatin, and omentin in puberty onset, fertility, and sexual maturation should be examined in detail. Secondly, future research examining the onset of puberty should combine indicators of puberty onset (e.g. breast development or testicular volume) with plasma or serum hor- mone measurements such as LH, FSH, sex-steroids, adipokines (e.g. spurts. ment in case of growth spurts. distribution of body fat should be taken into account in determining puberty and obesity in children. For instance, the body adiposity index (BAI), which was introduced in 2011 by Bergman et al.,87 uses hip cir- cumference and height in order to estimate the percentage of body 87 Thereby, BMI is a less accurate measure- F I G U R E 4 87,88 Therefore, both percentage and Average age of puberty onset in Europe, China, and the United States according to several studies from Table 1. Age of puberty onset ranges from 8.47 to 13.33 years in girls and from 8.63 leptin), and body fat distribution (e.g. BAI,87 waist-hip ratio's and/or dual-energy X-ray absorptiometry (DXA)2). Additionally, defining con- sistent and general measurements of puberty in both boys and girls, combined with a proper age range (8-16 years), would facilitate the comparisons between different studies and their results. 12-15, 17, 20-23, 25-29, 31 to 13.7 years in boys. included if average age of markers used to assess puberty was not reported. Pink: girls. Blue: boys Studies (Table 1) were not 39, 56 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 8 of 10 NIEUWENHUIS ET AL. 6 | CONCLUSION In conclusion, epidemiological data regarding obesity and puberty onset in girls show similar outcomes as adiposity results in the early onset of puberty in girls. The majority of the studies examining boys with obesity indicate an early onset of puberty, while not all reported an earlier onset of puberty. In detail, high leptin, TNF-α, and IL-6 levels combined with low adiponectin levels stimulate the activation of the HPG axis in girls and boys with obesity, and 5, 45, 50, 51 REFERENCES 1. Kumar S, Kelly AS. Review of childhood obesity: from epidemiology, etiology, and comorbidities to clinical assessment and treatment. May- o Clin Proc. 2017;92(2):251-265. 2. Reinehr T, Roth CL. Is there a causal relationship between obesity and puberty? The Lancet Child & adolescent health. 2019;3(1):44-54. 3. WorldHealthOrganization. Facts and figures on childhood obesity. 2017. 4. Guglielmi V, Sbraccia P. Obesity phenotypes: depot-differences in adipose tissue and their clinical implications. Eat Weight Disord. 2018; 23(1):3-14. 5. Gomez-Hernandez A, Beneit N, Diaz-Castroverde S. Escribano O. 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BMC Womens Health. 2018;18(1):168-174. thereby an early onset of obesity. leptin can inhibit the production of testosterone in boys and subse- quently inhibit the development of secondary sex characteristics affecting spermatogenesis. for other adipokines, like resistin and omentin, are present in the testes and ovaries suggesting a role in puberty or reproduction; 58, 71 however, their plausible function is still unknown. that adipokines may be key regulators in an early onset of puberty in both girls and boys with obesity, specifically by affecting the HPG axis during gonadarche. Future research should focus on assessing puberty onset by measuring consistent puberty markers and determine the percentage of body fat and its distribution and adipokines and hormone serum levels particularly involved in the HPG axis. CONFLICTS OF INTEREST The authors declare no conflict of interest. FUNDING INFORMATION This research was funded by Europees Fonds voor Regionale Ontwikkeling (EFRO), project BriteN 2016. ORCID Ilse A.C. Arnoldussen Amanda J. Kiliaan https://orcid.org/0000-0002-7395-5284 https://orcid.org/0000-0002-2158-6210 13, 14, 16-26, 29-32 Furthermore, several receptors Nevertheless, We conclude Search strategy We searched PubMed for articles published before Novem- ber 15th, 2019 using relevant keywords, including ‘onset of puberty and adiposity/obesity’, ‘onset of puberty’, ‘children with obesity’, ‘adipose tissue’, ‘childhood obesity’, ‘adiposity’, ‘obesity’, ‘adipokine(s)’, ‘HPG axis’, ‘adipokines ovary/ova- ries’, or ‘adipokines testes’, either alone or in combination. 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Obesity Reviews. 2020;21:e13005. https://doi.org/ 10.1111/obr.13005 1467789x, 2020, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/obr.13005, Wiley Online Library on [10/03/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are goverOwls, such as the young snowy owls on the previous page, have for centuries been symbols of both wisdom and mystery. To many cultures their piercing eyes have conveyed a look of intelligence. Their silent flight through darkened landscapes in search of prey has projected an air of power or wonder. For this chapter and this book, owls are an engaging example of a living organism from the world of biology—the study of life. BIOLOGY AND YOU Living in a small town, in the country, or at the edge of the suburbs, one may be lucky enough to hear an owl's hooting. This experience can lead to questions about where the bird lives, what it hunts, and how it finds its prey on dark, moonless nights. Biology, or the study of life, offers an organized and scientific framework for posing and answering such questions about the natural world. Biologists study questions about how living things work, how they interact with the environment, and how they change over time. Biologists study many different kinds of living things ranging from tiny organisms, such as bacteria, to very large organisms, such as elephants. Each day, biologists investigate subjects that affect you and the way you live. For example, biologists determine which foods are healthy. As shown in Figure 1-1, everyone is affected by this impor- tant topic. Biologists also study how much a person should exer- cise and how one can avoid getting sick. Biologists also study what CHARACTERISTICS OF LIFE The world is filled with familiar objects, such as tables, rocks, plants, pets, and automobiles. Which of these objects are living or were once living? What are the criteria for assigning something to the living world or the nonliving world? Biologists have established that living things share seven characteristics of life. These characteristics are organization and the presence of one or more cells, response to a stimulus (plural, stimuli), homeostasis, metabolism, growth and development, reproduction, and change through time. Organization and Cells Organization is the high degree of order within an organism’s internal and external parts and in its interactions with the living world. For example, compare an owl to a rock. The rock has a spe- cific shape, but that shape is usually irregular. Furthermore, differ- ent rocks, even rocks of the same type, are likely to have different shapes and sizes. In contrast, the owl is an amazingly organized individual, as shown in Figure 1-2. Owls of the same species have the same body parts arranged in nearly the same way and interact with the environment in the same way. Copyright © by Holt, Rinehart and Winston. All rights reserved. ORGANISM (Barn Owl) ORGAN (Owl’s Ear) TISSUE (Nervous Tissue Within the Ear) CELL (Nerve Cell) your air, land, and fAll living organisms, whether made up of one cell or many cells, have some degree of organization. A cell is the smallest unit that can perform all life’s processes. Some organisms, such as bacteria, are made up of one cell and are called unicellular (YOON-uh-SEL-yoo-luhr) organisms. Other organisms, such as humans or trees, are made up of multiple cells and are called multicellular (MUHL-ti-SEL-yoo-luhr) organisms. Complex multicellular organisms have the level of orga- nization shown in Figure 1-2. In the highest level, the organism is made up of organ systems, or groups of specialized parts that carry out a certain function in the organism. For example, an owl’s ner- vous system is made up of a brain, sense organs, nerve cells, and other parts that sense and respond to the owl’s surroundings. Organ systems are made up of organs. Organs are structures that carry out specialized jobs within an organ system. An owl’s ear is an organ that allows the owl to hear. All organs are made up of tissues. Tissues are groups of cells that have similar abilities and that allow the organ to function. For example, nervous tissue in the ear allows the ear to detect sound. Tissues are made up of cells. A cell must be covered by a membrane, contain all genetic information necessary for replication, and be able to carry out all cell functions. Within each cell are organelles. Organelles are tiny structures that carry out functions necessary for the cell to stay alive. Organelles contain biological molecules, the chemical compounds that provide physical structure and that bring about movement, energy use, and other cellular functions. All biological molecules are made up of atoms. Atoms are the simplest particle of an ele- ment that retains all the properties of a certain element. Response to Stimuli Another characteristic of life is that an organism can respond to a stimulus—a physical or chemical change in the internal or external environment. For example, an owl dilates its pupils to keep the level of light entering the eye constant. Organisms must be able to respond and react to changes in their environment to stay alive. ORGANELLE (Mitochondrion) BIOLOGICAL MOLECULE (Phospholipid) ATOM (Oxygen) cell from the Latin, cella meaning “small room,” or “hut” Word Roots and Origins www.scilinks.org Topic: Characteristics of Life Keyword: HM60257 mb06se_bios01.qxd 5/18/07 10:37 AM Page 7 8 CHAPTER 1 Homeostasis All living things, from single cells to entire organisms, have mecha- nisms that allow them to maintain stable internal conditions. Without these mechanisms, organisms can die. For example, a cell’s water content is closely controlled by the taking in or releas- ing of water. A cell that takes in too much water will rupture and die. A cell that doesn’t get enough water will also shrivel and die. Homeostasis (HOH-mee-OH-STAY-sis) is the maintenance of a stable level of internal conditions even though environmental conditions are constantly changing. Organisms have regulatory systems that maintain internal conditions, such as temperature, water content, and uptake of nutrients by the cell. In fact, multi- cellular organisms usually have more than one way of maintain- ing important aspects of their internal environment. For example, an owl’s temperature is maintained at about 40°C (104°F). To keep a constant temperature, an owl’s cells burn fuel to produce body heat. In addition, an owl’s feathers can fluff up in cold weather. In this way, they trap an insulating layer of air next to the bird’s body to maintain its body temperature. Metabolism Living organisms use energy to power all the life processes, such as repair, movement, and growth. This energy use depends on metabolism (muh-TAB-uh-LIZ-uhm). Metabolism is the sum of all the chemical reactions that take in and transform energy and materials from the environment. For example, plants, algae, and some bacteria use the sun’s energy to generate sugar molecules during a process called photosynthesis. Some organisms depend on obtaining food energy from other organisms. For instance, an owl’s metabolism allows the owl to extract and modify the chemi- cals trapped in its nightly prey and use them as energy to fuel activities and growth. Growth and Development All living things grow and increase in size. Some nonliving things, such as crystals or icicles, grow by accumulating more of the same material of which they are made. In contrast, the growth of living things results from the division and enlargement of cells. Cell division is the formation of two new cells from an existing cell, as shown in Figure 1-3. In unicellular organisms, the primary change that occurs following cell division is cell enlargement. In multi- cellular life, however, organisms mature through cell division, cell enlargement, and development. Development is the process by which an organism becomes a mature adult. Development involves cell division and cell differen- tiation, or specialization. As a result of development, an adult organism is composed of many cells specialized for different func- tions, such as carrying oxygen in the blood or hearing. In fact, the human body is composed of trillions of specialized cells, all of which originated from a single cell, the fertilized egg. This unicellular organism, Escherichia coli, inhabits the human intestines. E. coli reproduces by means of cell division, during which the original cell splits into two identical offspring cells. FIGURE 1-3 Observing Homeostasis Materials 500 mL beakers (3), wax pen, tap water, thermometer, ice, hot water, goldfish, small dip net, watch or clock with a second hand Procedure 1. Use a wax pen to label three 500 mL beakers as follows: 27°C (80°F), 20°C (68°F), 10°C (50°F). Put 250 mL of tap water in each beaker. Use hot water or ice to adjust the tem- perature of the water in each beaker to match the temperature on the label. 2. Put the goldfish in the beaker of 27°C water. Record the number of times the gills move in 1 minute. 3. Move the goldfish to the beaker of 20°C water. Repeat observations. Move the goldfish to the beaker of 10°C. Repeat observations. Analysis What happens to the rate at which gills move when the temp- erature changes? Why? How do gills help fish maintain homeostasis? Quick Lab mb06se_bios01.qxd 5/18/07 10:37 AM Page 8 THE SCIENCE OF LIFE 9 Reproduction All organisms produce new organisms like themselves in a process called reproduction. Reproduction, unlike other characteristics, is not essential to the survival of an individual organism. However, because no organism lives forever, reproduction is essential for the continuation of a species. Glass frogs, as shown in Figure 1-4, lay many eggs in their lifetime. However, only a few of the frogs’ off- spring reach adulthood and successfully reproduce. During reproduction, organisms transmit hereditary informa- tion to their offspring. Hereditary information is encoded in a large molecule called deoxyribonucleic acid, or DNA. A short segment of DNA that contains the instructions for a single trait of an organism is called a gene. DNA is like a large library. It contains all the books—genes—that the cell will ever need for making all the struc- tures and chemicals necessary for life. Hereditary information is transferred to offspring during two kinds of reproduction. In sexual reproduction, hereditary information recombines from two organisms of the same species. The resulting offspring are similar but not identical to their parents. For example, a male frog’s sperm can fertilize a female’s egg and form a single fer- tilized egg cell. The fertilized egg then develops into a new frog. In asexual reproduction, hereditary information from different organisms is not combined; thus the original organism and the new organism are genetically the same. A bacterium, for example, reproduces asexually when it splits into two identical cells. Change Through Time Although individual organisms experience many changes during their lifetime, their basic genetic characteristics do not change. However, populations of living organisms evolve or change through time. The ability of populations of organisms to change over time is important for survival in a changing world. This factor is also impor- tant in explaining the diversity of life-forms we see on Earth today. 1. How does biology affect a person’s daily life? 2. How does biology affect society? 3. Name the characteristics shared by living things. 4. Summarize the hierarchy of organization found in complex multicellular organisms. 5. What are the different functions of homeostasis and metabolism in living organisms? 6. How does the growth among living and nonliv- ing things differ? 7. Why is reproduction an important characteristic of life? CRITICAL THINKING 8. Applying Information Crystals of salt grow and are highly organized. Why don’t biologists con- sider them to be alive? 9. Analyzing Models When a scientist designs a space probe to detect life on a distant planet, what kinds of things should it measure? 10. Making Comparisons Both cells and organisms share the characteristics of life. How are cells and organismsood supply will be like in the near future.EVOLUTION OF LIFE Individual organisms change during their lifetime, but their basic genetic characteristics do not change. However, populations of liv- ing organisms do change through time, or evolve. Evolution, or descent with modification, is the process in which the inherited characteristics within populations change over generations, such that genetically distinct populations and new species can develop. Evolution as a theme in biology helps us understand how the various branches of the “tree of life” came into existence and have changed over time. It also explains how organisms alive today are related to those that lived in the past. Finally, it helps us understand the mechanisms that underlie the way organisms look and behave. Natural Selection The ability of populations of organisms to change over time is important for survival in a changing world. According to the theory of evolution by natural selection, organisms that have certain favorable traits are better able to survive and reproduce success- fully than organisms that lack these traits. One product of natural selection is the adaptation of organisms to their environment. Adaptations are traits that improve an indi- vidual’s ability to survive and reproduce. For example, rabbits with white fur and short ears in a snowy place, such as the one in Figure 1-7a, may avoid predators and frostbitten ears more often than those with dark fur and long ears. Thus, the next generation of rabbits will have a greater percentage of animals carrying the genes for white fur and short ears. In contrast, the brown, long- eared rabbit, as shown in Figure 1-7b, would survive and reproduce more successfully in a hot desert environment. The survival and reproductive success of organisms with favor- able traits cause a change in populations of organisms over gener- ations. This descent with modification is an important factor in explaining the diversity of organisms we see on Earth today. 1. Name three unifying themes found in biology. 2. How is the unity and diversity in the living world represented? 3. Identify the three domains and the kingdoms found in each domain. 4. How are organisms interdependent? 5. Describe why evolution is important in explain- ing the diversity of life. 6. Distinguish between evolution and natural selection. CRITICAL THINKING 7. Applying Information Assign the various top- pings you put on pizza to the appropriate domains and kingdoms of life. 8. Analyzing Graphics According to the “tree” in Figure 1-5, which of these pairs are more closely related: Archaea:Bacteria or Archaea:Eukarya? 9. Making Hypotheses Fossil evidence shows that bats descended from shrewlike organisms that could not fly. Write a hypothesis for how natural selection might have led to flying bats. SECTION 2 REVIEW (a) This short-eared arctic hare, Lepus arcticus, is hidden from predators and protected from frostbite in a snowy environment. (b) The mottled brown coats of desert rabbits blend in with the dirt and dry grasses, and their long ears help them radiate excess heat and thus avoid overheating. FIGURE 1-7 (a) (b) Copyright © by Holt, Rinehart and Winston. All rights reserved. THE SCIENCE OF LIFE 13 TH E STUDY OF BIOLOGY Curiosity leads us to ask questions about life. Science provides a way of answering such questions about the natural world. Science is a systematic method that involves forming and testing hypotheses. More importantly, science relies on evidence, not beliefs, for drawing conclusions. SCIENCE AS A PROCESS Science is characterized by an organized approach, called the scientific method, to learn how the natural world works. The methods of science are based on two important principles. The first principle is that events in the natural world have natural causes. For example, the ancient Greeks believed that lightning and thunder occurred because a supernatural god Zeus hurled thunderbolts from the heavens. By contrast, a scientist considers lightning and thunder to result from electric charges in the atmos- phere. When trying to solve a puzzle from nature, all scientists, such as the one in Figure 1-8, accept that there is a natural cause to solve that puzzle. A second principle of science is uniformity. Uniformity is the idea that the fundamental laws of nature operate the same way at all places and at all times. For example, scientists assume that the law of gravity works the same way on Mars as it does on Earth. Steps of the Scientific Method Although there is no single method for doing science, scientific studies involve a series of common steps. 1. The process of science begins with an observation. An observation is the act of perceiving a natural occurrence that causes someone to pose a question. 2. One tries to answer the question by forming hypotheses (singular, hypothesis). A hypothesis is a proposed explanation for the way a particular aspect of the natural world functions. 3. A prediction is a statement that forecasts what would happen in a test situation if the hypothesis were true. A prediction is recorded for each hypothesis. 4. An experiment is used to test a hypothesis and its predictions. 5. Once the experiment has been concluded, the data are analyzed and used to draw conclusions. 6. After the data have been analyzed, the data and conclusions are communicated to scientific peers and to the public. This way oth- ers can verify, reject, or modify the researcher’s conclusions. SECTION 3 OBJECTIVES ● Outline the main steps in the scientific method. ● Summarize how observations are used to form hypotheses. ● List the elements of a controlled experiment. ● Describe how scientists use data to draw conclusions. ● Compare a scientific hypothesis and a scientific theory. ● State how communication in science helps prevent dishonesty and bias. VOCABULARY scientific method observation hypothesis prediction experiment control group experimental group independent variable dependent variable theory peer review All researchers, such as the one releasing an owl above, use the scientific method to answer the questions they have about nature. FIGURE 1-8 Copyright © by Holt, Rinehart and Winston. All rights reserved. 14 CHAPTER 1 OBSERVING AND ASKING QUESTIONS The scientific method generally begins with an unexplained observa- tion about nature. For example, people have noticed for thousands of years that owls can catch prey in near total darkness. As shown in steps and of Figure 1-9, an observation may then raise ques- tions. The owl observation raises the question: How does an owl detect prey in the dark? FORMING A HYPOTHESIS After stating a question, a biologist lists possible answers to a sci- entific question—hypotheses. Good hypotheses answer a question and are testable in the natural world. For example, as shown in step Figure 1-9, there are several possible hypotheses for the question of how owls hunt at night: (a) owls hunt by keen vision in the dark; (b) owls hunt by superb hearing; or (c) owls hunt by detecting the prey’s body heat. Predicting To test a hypothesis, scientists make a prediction that logically fol- lows from the hypothesis. A prediction is what is expected to hap- pen if each hypothesis were true. For example, if hypothesis (a) is true, (owls hunt by keen night vision) then one can predict that the owl will pounce only on the mouse in either a light or a dark room. If hypothesis (b) is true (owls hunt by hearing), then one can pre- dict that in a lighted room, the owl will pounce closer to the mouse’s head. But, in a dark room, the owl should pounce closer to a rustling leaf attached to the mouse. Finally, if hypothesis (c) is true (owls hunt by sensing body heat), then an owl would strike only the prey no matter the room conditions, because owls hunt by detecting the prey’s body heat. 3 1 2 Copyright © by Holt, Rinehart and Winston. All rights reserved. A scientific study includes observations, questions, hypotheses, predictions, experiments, data analysis, and conclu- sions. A biologist can use the scientific method to set up an experiment to learn how an owl captures prey at night. FIGURE 1-9 1 OBSERVATION Owls capture prey on dark nights. 2 QUESTION How do owls detect prey on dark nights? 3 HYPOTHESES a) Owls hunt in the dark by vision. b) Owls hunt in the dark by hearing. c) Owls hunt in the dark by sensing body heat. THE SCIENCE OF LIFE 15 Notice that these predictions make it difficult to distinguish be- tween the vision and body heat hypotheses. The reason is that both hypotheses predict that the owl could grab the mouse in a dark room. Also, these three hypotheses do not eliminate all other factors that could influence how the owl finds its prey. However, testing predictions can allow one to begin rejecting hypotheses and thus to get closer to determining the answer(s) to a question. DESIGNING AN EXPERIMENT Biologists often test hypotheses by setting up an experiment. Step in Figure 1-9 outlines an experiment to test the hypotheses about how an owl hunts at night. First, experimenters set up a room with an owl perch high on one side and a small trap door on the other side for releasing mice. Then, they tied a leaf to each mouse’s tail with a string and released each mouse into the room. Next, each mouse ran silently across the room, but the leaf trailed behind, making a rustling noise. During half of the trials, the lights were on. During the other half, the room was dark. Technicians videotaped all the action in the chamber with an infrared light, which owls cannot see. The researchers then viewed the videos and measured the position of the owl’s strike relative to each mouse’s head. Performing the Experiment Many scientists use a controlled experiment to test their hypotheses. A controlled experiment compares an experimental group and a control group and only has one variable. The control group pro- vides a normal standard against which the biologist can compare results of the experimental group. The experimental group is iden- tical to the control group except for one factor, the independent variable. The experimenter manipulates the independent variable, sometimes called the manipulated variable. 4 4 EXPERIMENT 5 DATA COLLECTION AND ANALYSIS Measure and compare the distance from the owl’s strike to the mouse and to the leaf in light and dark. 6 CONCLUSION Data supported the hearing hypothesis: Owls hunt in the dark by hearing. prey Test predictions of the three hypotheses. Control: In the light Experimental: In the dark 1 2 3 4 5 6 7 8 9 10 11 Predicting Results Materials 2 Petri dishes with agar, cellophane tape, wax pen Procedure 1. Open one of the Petri dishes, and streak your finger across the surface of the agar. 2. Replace the lid, and seal it with the tape. Label this Petri dish with your name and a number 1. 3. Seal the second Petri dish with- out removing the lid. Label this Petri dish with your name and the number 2. 4. Write a prediction about what will happen in each dish. Store your dishes as your teacher directs. Record your observations. Follow your teacher’s directions for disposal of your dishes. Analysis Was your prediction accurate? What evidence can you cite to support your prediction? If you did not obtain the results you predicted, would you change your testing method or your prediction? Explain. Evaluate the importance of obtaining a result that does not support your prediction. Quick Lab mb06se_bios03.qxd 5/18/07 10:40 AM Page 15 16 CHAPTER 1 The independent variable in the owl experiment is the presence or absence of light. In the owl experiment, the control group hunts in the light, and the experimental group hunts in the dark. In addi- tion to varying the independent variable, a scientist observes or measures another factor called the dependent variable, or respond- ing variable, because it is affected by the independent variable. In the owl experiment, the dependent variable is distance from the owl’s strike to the mouse’s head. Testing the Experiment Some controlled experiments are conducted “blind.” In other words, the biologist who scores the results is unaware of whether a given subject is part of the experimental or control group. This factor helps eliminate experimenter bias. Experiments should also be repeated, because living systems are variable. Moreover, scien- tists must collect enough data to find meaningful results. COLLECTING AND ANALYZING DATA Most experiments measure a variable—the dependent variable. This measurement provides quantitative data, data measured in numbers. For example, in the experiment above, scientists mea- sured the distance of an owl’s strike from the prey’s head in cen- timeters, as shown in step of Figure 1-9. An event’s duration in milliseconds is also an example of quantitative data. Biologists usually score the results of an experiment by using one of their senses. They might see or hear the results of an experiment. Scientists also extend their senses with a micro- scope for tiny objects or a microphone for soft sounds. In the owl experiment, biologists extended their vision with infrared cameras. Analyzing and Comparing Data After collecting data from a field study or an experiment and then organizing it, biologists then analyze the data. In analyzing data, the goal is to determine whether the data are reliable, and whether they support or fail to support the predictions of the hypothesis. To do so, scientists may use statistics to help determine relation- ships between the variables involved. They can then compare their data with other data that were obtained in other similar studies. It is also important at this time to determine possible sources of error in the experiment just per- formed. Scientists usually display their data in tables or graphs when analyzing it. For the owl study, biologists could have made a bar graph such as the one in Figure 1-10, which shows the average distance from the owl’s strike relative to the mouse’s head or the leaf in the light and in the dark. 5 5 0 10 15 20 25 In the light In the dark Average distance from strike (cm) Distance Between Owl Strike and a Mouse or From a Leaf Attached to Mouse 30 Mouse Leaf Mouse Leaf The data below are hypothetical results that might occur from the described owl experiment.The independent variable is the darkness of the room, and the dependent variable is how far the owl struck from the mouse’s head.The data show that the owl strikes more accurately at the mouse in the light but strikes more accurately at the leaf in the dark. FIGURE 1-10 Copyright © by Holt, Rinehart and Winston. All rights reserved. THE SCIENCE OF LIFE 17 DRAWING CONCLUSIONS Biologists analyze their tables, graphs, and charts to draw conclu- sions about whether or not a hypothesis is supported, as shown in step of Figure 1-9. The hypothetical owl data show that in the light, owls struck with greater accuracy at the mouse than at the leaf, but in the dark, owls struck with greater accuracy at the leaf than the mouse. Thus, the findings support the hearing hypothe- sis, but not the vision hypothesis. An experiment can only disprove, not prove, a hypothesis. For example, one cannot conclude from the results that the hearing hypothesis is proven to be true. Perhaps the owl uses an unknown smell to strike at the mouse. One can only reject the vision hypothe- sis because it did not predict the results of the experiment correctly. Acceptance of a hypothesis is always tentative in science. The scientific community revises its understanding of phenomena, based on new data. Having ruled out one hypothesis, a biologist will devise more tests to try to rule out any remaining hypotheses. Making Inferences Scientists often draw inferences from data gathered during a field study or experiment. An inference (IN-fuhr-uhns) is a conclusion made on the basis of facts and previous knowledge rather than on direct observations. Unlike a hypothesis, an inference is not directly testable. In the owl study, it is inferred that the owl detects prey from a distance rather than by direct touch. Applying Results and Building Models As shown in Figure 1-11, scientists often apply their findings to solve practical problems. They also build models to represent or describe things. For example in 1953, James Watson and Francis Crick used cardboard balls and wire bars to build physical models of atoms in an attempt to understand the structure of DNA. Mathematical models are sets of equations that describe how dif- ferent measurable items interact in a system. The experimenter can adjust variables to better model the real-world data. CONSTRUCTING A THEORY When a set of related hypotheses is confirmed to be true many times, and it can explain a great amount of data, scientists often reclassify it as a theory. Some examples include the quantum the- ory, the cell theory, or the theory of evolution. People commonly use the word “theory” in a different way than scientists use the word. People may say “It’s just a theory” suggesting that an idea is untested, but scientists view a theory as a highly tested, generally accepted principle that explains a vast number of observations and experimental data. 6 Copyright © by Holt, Rinehart and Winston. All rights reserved. Biologists often apply their knowledge of the natural world to practical problems. Studies on the owl’s keen ability to locate sounds in space despite background noise are helping biotechnologists and bioengineers develop better solutions for people with impaired hearing, such as the people shown in this picture. FIGURE 1-11 18 CHAPTER 1 COMMUNICATING IDEAS An essential aspect of scientific research is scientists working together. Scientists often work together in research teams or sim- ply share research results with other scientists. This is done by publishing findings in scientific journals or presenting them at sci- entific meetings, as shown in Figure 1-12. Sharing information allows others working independently to verify findings or to con- tinue work on established results. For example, Roger Payne pub- lished the results of his owl experiments in a journal in 1971. Then, other biologists could repeat it for verification or use it to study the mechanisms introduced by the paper. With the growing impor- tance of science in solving societal issues, it is becoming increas- ingly vital for scientists to be able to communicate with the public at large. Publishing a Paper Scientists submit research papers to scientific journals for publica- tion. A typical research paper has four sections. First, the Introduction poses the problem and hypotheses to be investigated. Next, the Materials and Methods describe how researchers proceeded with the experiment. Third, the Results state the findings the experiment presented, and finally, the Discussion gives the significance of the experiment and future directions the scientists will take. Job Description Forensic biolo- gists are scientists who study biological materials to investigate potential crimes and other legal issues against humans and animals. Forensic scientists have knowledge in areas of biology, such as DNA and blood pattern analysis, and work in private sector and public laboratories. Focus On a Forensic Biologist As a law enforcement forensic specialist for the Texas Parks and Wildlife Department, Beverly Villarreal assists the game warden in investigations of fish and wildlife violations, such as illegal hunting and fishing. Villarreal analyzes blood and tissue samples to identify species of animals such as fish, birds, and reptiles. Her work helps game wardens as they enforce state laws regarding hunting and fishing. Most people think of forensic scientists as the glamorous crime investigators on TV, but according to Villarreal real forensic scientists “spend a great deal of time at a lab bench running analysis after analysis.” Many of the methods used in animal forensics, such as DNA sequenc- ing, are also used in human forensics. Education and Skills • High school—three years of science courses and four years of math courses. • College—bachelor of science in biol- ogy, including course work in zoology and genetics, plus experience in per- forming DNA analyses. • Skills—patience, attention to detail, and ability to use fine tools. Careers in BIOLOGY Forensic Biologist For more about careers, visit go.hrw.com and type in the keyword HM6 Careers. www.scilinks.org Topic: Scientific Investigations Keyword: HM61358 mb06se_bios03.qxd 5/18/07 10:40 AM Page 18 THE SCIENCE OF LIFE 19 1. What two principles make the scientific method a unique process? 2. Define the roles of observations and hypotheses in science. 3. Summarize the parts of a controlled experiment. 4. Summarize how we make conclusions about the results of an experiment. 5. Why is the phrase, “it’s just a theory” misleading? 6. Give another example of a conflict of interest. CRITICAL THINKING 7. Making Hypotheses On a nocturnal owl’s skull, one ear points up, and the other ear points down. Suggest a hypothesis for this observation. 8. Designing Experiments Design an experiment to establish if owls hunt by keen sight or hunt by heat seeking. 9. Calculating Information What was the average distance between the owl’s strike and the mouse if the recorded differences in this experiment were 25, 22, 19, 19, and 15? SECTION 3 REVIEW After scientists submit their papers to a scientific journal, the editors of that journal will send the paper out for peer review. In a peer review, scientists who are experts in the field anonymously read and critique that research paper. They determine if a paper pro- vides enough information so that the experiment can be duplicated and if the author used good experimental controls and reached an accurate conclusion. They also check if the paper is written clearly enough for broad understanding. Careful analysis of each other’s research by fellow scientists is essential to making scientific progress and preventing scientific dishonesty. HONESTY AND BIAS The scientific community depends on both honesty and good sci- ence. While designing new studies, experimenters must be very careful to prevent previous ideas and biases from tainting both the experimental process and the conclusions. Scientists have to keep in mind that they are always trying to disprove their favorite ideas. Scientists repeat experiments to verify previous findings. This allows for science to have a method for self-correction and it also keeps researchers honest and credible to their peers in the field. Conflict of Interest For most scientists, maintaining a good reputation for collecting and presenting valid data is more important than temporary prestige or income. So, scientists try to avoid any potential conflicts of interest. For example, a scientist who owns a biotechnology company and manufactures a drug would not be the best researcher to critically test that drug’s safety and effectiveness. To avoid this potential con- flict of interest, the scientist allows an unaffected party, such as a research group, to test the drug’s effectiveness. The threat of a potential scandal based on misleading data or conclusions is a pow- erful force in science that helps keep scientists honest and fair. Scientists present their experiments in various forms. The scientists above are presenting their work in the form of a poster at a scientific meeting. FIGURE 1-12 Copyright © by Holt, Rinehart and Winston. All rights reserved. The Internet can provide a wealth of scientific information for a report, but the information may not always be credible or accurate. You can use the methods above to check the accuracy and credibility of your sources. SCIENCE TECHNOLOGY SOCIETY SCIENCE ON THE INTERNET: A New Information Age I n the past, students research- ing a science topic would typ- ically begin their research by visiting a library to use printed reference materials, such as encyclopedias. Today, most stu- dents research topics by using a computer and searching for information on the Internet. The Internet can provide students with a wealth of infor- mation. But which Web sites have accurate information, and which Web sites do not? Checking Web Addresses Students should use the Web address, or URL, to establish the Web site’s credibility. Usually, the domain name can suggest who has published the Web site. Web sites can be pub- lished by governmental agen- cies (ends in “dot gov” or .gov), by educational institutions (ends in “dot edu” or .edu), by organizations (ends in “dot org” or .org), or by commercial businesses (ends in “dot com” or .com). Government Web sites are usually reliable. Examples of credible governmental Web sites are the National Institutes of Health (NIH) and the Food and Drug Administration (FDA). University and medical school sites are also reliable sources of information. Many organiza- tions that research and teach the public about specific diseases and conditions can also provide reliable information. Examples of such organizations are the American Cancer Society and the American Heart Association. Evaluating Web Sites The credibility of the author of the Web site should also be checked. Make sure the author is not trying to sell anything and is established in his or her field. For example, a health Web site’s author should be a med- ical professional. It is also important to check the date that the information was posted on the Web to ensure that the information is current. Also, the Web site should provide ref- erences from valid sources, such as scientific journals or govern- ment publications. Finally, the student should always double-check informa- tion between several reliable Web sites. If two or three reliable sites provide the same informa- tion, the student can feel confi- dent in using that information. Web Sites for Students The Internet Connect boxes in this textbook have all been reviewed by professionals at the National Science Teachers Association (NSTA). Students can trust that these sites are reliable sources for science- or health-related topics. REVIEW 1. Which types of Web addresses are the most reliable? 2. List four important features to evaluate when using a Web site for research. 3. Supporting Reasoned Opinions Why do you think a Web site that is advertising a product may not offer accurate information? REVIEW 20 www.scilinks.org Topic: Using the Internet Keyword: HM61589 mb06se_biosts.qxd 5/18/07 10:42 AM Page 20 TOOLS AND TECHNIQUES With proper equipment and good methods, biologists can see, manipulate, and understand the natural world in new ways. Microscopes are one of many useful tools used to unlock nature’s biological secrets. MICROSCOPES AS TOOLS Tools are objects used to improve the performance of a task. Microscopes are tools that extend human vision by making enlarged images of objects. Biologists use microscopes to study organisms, cells, cell parts, and molecules. Microscopes reveal details that otherwise might be difficult or impossible to see. Light Microscopes To see small organisms and cells, biologists typically use a light microscope, such as the one shown in Figure 1-13. A compound light microscope is a microscope that shines light through a spec- imen and has two lenses to magnify an image. To use this micro- scope, one first mounts the specimen to be viewed on a glass slide. The specimen must be thin enough for light to pass through it. For tiny pond organisms, such as the single-celled paramecium, light passing through the organism is not a problem. For thick objects, such as plant stems, biologists must cut thin slices for viewing. There are four major parts of a compound light microscope. For further description of the parts of a micro- scope, see the Appendix. 1. Eyepiece The eyepiece (ocular (AHK-yoo-luhr) lens) magnifies the image, usually 10 times. 2. Objective Lens Light passes through the specimen and then through the objective lens, which is located directly above the specimen. The objective lens enlarges the image of the specimen. Scientists sometimes use stains to make the image easier to see. 3. Stage The stage is a platform that supports a slide holding the specimen. The slide is placed over the opening in the stage of the microscope. 4. Light Source The light source is a light bulb that provides light for viewing the image. It can be either light reflected with a mirror or an incandescent light from a small lamp. SECTION 4 OBJECTIVES ● List the function of each of the major parts of a compound light microscope. ● Compare two kinds of electron microscopes. ● Describe the importance of having the SI system of measurement. ● State some examples of good laboratory practice. VOCABULARY compound light microscope eyepiece (ocular lens) objective lens stage light source magnification nosepiece resolution scanning electron microscope transmission electron microscope metric system base unit Compound light microscopes open the human eye to an interesting world including tiny pond organisms, healthy and diseased cells, and the functioning of cell parts. FIGURE 1-13 Objective lens Eyepiece (ocular lens) Stage Light THE SCIENCE OF LIFE 21 Copyright © by Holt, Rinehart and Winston. All rights reserved. 22 CHAPTER 1 Magnification and Resolution Microscopes vary in powers of magnification and resolution. Magnification is the increase of an object’s apparent size. Revolving the nosepiece, the structure that holds the set of objective lens, rotates these lenses into place above the specimen. In a typical com- pound light microscope, the most powerful objective lens produces an image up to 100 times (100) the specimen’s actual size. The degree of enlargement is called the power of magnification of the lens. The standard ocular lens magnifies a specimen 10 times (10). To compute the power of magnification of a microscope, the power of magnification of the strongest objective lens (in this case, 100) is multiplied by the power of magnification of the ocular lens (10). The result is a total power of magnification of 1000. Resolution (REZ-uh-LOO-shuhn) is the power to show details clearly in an image. The physical properties of light limit the ability of light microscopes to resolve images, as shown in Figure 1-14a. At pow- ers of magnification beyond about 2,000, the image of the speci- men becomes fuzzy. For this reason, scientists use other microscopes to view very small cellsAbstract The main focus of this research is to discuss the perspective of the teamwork and its impaction organizational performance and success. Also highlight the Meanings of Team and its work sprit towards batter organizational performance and specific to its impact on the success of organization that provided the basis for this research study. In this research study a thoroughly focus was on organization and teamwork. The aim of this research is to deliver a participative view of teamwork in the organization, and also discourses the major issues and emphases on the recent work that opens the basis to move research onward. There is much worth in taking a more focus on the essential areas of teamwork. The team signifies the spirit and working capacity of the employees as team to bring organization to the success. The various explanations, definitions, processes, dimensions, team size and benefits etc. regarding the above topic teamwork and organizational success is highlighted. Keywords: Teamwork, Success, Organization, Performance, Work Groups, Employees Introduction It is indeed human beings have learned in their beginning of life to work together as (Team) that have made such a remarkable developments as unique specie. Human beings have experience throughout their social history, lived, loved, grow younger to older and worked together in groups said West M.A. (2012).The mutual social knowledge of living and functioning together creates connection among people, society and families. When work is done cooperatively as a team it can achieve extremely extra work than individually. Team can be defined as in the human society to live, to work and to play and to cooperate with others for particular task. According to John W. Newstrom et al (1993) “team is the process of assessing performance of workers, passing information and exploring methods to increase performance”. If observe closely, one can discover the instances of The Government: Research Journal of Political Science Supplementary Edition Vol. III 88 The Government social (teams) they are functioning either effectively or ineffectively everywhere; organizations, schools, work place, home etc. “Coordinating the events of people is like sand house, making by using a sole particles of sand” expressed Belbin, R. M.(2010). Moreover it is one of the general myths that the skill of team member is more important than their vigor, attention and determination for the tasks. Another widespread myth is that the team members are not alone accountable for the achievements or failures of their tasks the truth is that the members are the small parts in the teams and their individual abilities effect on the various results in team. The working relationships exist among team that might sight these relationships at different levels of involvement or relationships among the members as they move towards the degree of communication, integration and commitment increases. Terry L.G. et al (1980) expressed that “The skills are essential if members have to work together efficiently in complex situations, only development of skills and relationships, involvement on the task regarding the particular task might be selected for reaching at target that is considered as a definition of a team”. Team often perform higher when they work together with sprit that enable them to achieve a collective goal at the workplace, it is not only benefits to the organization also affects the workers confidence and success. Cooperating on various tasks reduces workloads for all team members and enables them to share duties or ideas. Work as a team is the part of everyone's life, as one is a member of a family team, staff team, school team, and community teams etc., so as to understand how to work effectively as a team member. Especially there is a need when task is threatened with increasingly many problems for example; the energy problem has effects on organization, family life, and social development and the multi-dimensional nature of many problems require a scientific skill based problem solving approach. Terry L.G, et al (1980) expressed that “The skills, competencies and efforts of team by setting priorities the team can have better impact on the problems solving such efforts can reduce work load, work duplication, and produce a result better than separate efforts”. There are some processes of teamwork by adopting those the objectives can be achieved easily. Le Pine, et al, (2008) identified10 teamwork processes that fall in three categories following are those. TEAMWORK PROCESSES TRANSITION PROCESSES •Mission analysis •Goal specification •Strategy formulation ACTION PROCESSES •Monitoring progress toward goals •Systems monitoring •Team monitoring and backup behavior •Coordination INTERPERSONAL PROCESSES •Conflict management •Motivation and confidence building •Affect management Team Work 89 Teamwork process reduces the work stress on every member which permits members to complete given important task of organization; teamwork offers members an opening to pledge with each other. Also it develops relations between the members who start a teamwork they usually sense appreciated on productive accomplishment of task. It may be cited one of the best instances of surgical team; where surgeon is assisted by his team; nurses, anesthetist and experts etc., everyone knows that their success depends upon the teamwork. In addition they are devoted to the aim that is human life it is easy to succeed with best teamwork. The important role of manager is the team building, trust building, confidence building, in the team to achieve the task. In the Situation where all team members contribute the task, it develops the positive relationship in the team that improves the trust of team members.“Functions effectively members of team must be flexible, committed, trusting each other and help to each other’s in the progress and the achievement of goals” Expressed Plamínek (2008). The accountability of every member in the team must be increased so that they do not let each other down therefore they do their best for the achievements of their teams. In contrast, working alone on a task the pressure is generally high in team in those cases of small confidence impacts fewer on members. Team consists on members who always vary from each other’s in skills, knowledge and abilities but working together that is an opportunity for them to gain skills and knowledge from each other’s that they had never before. Working alone on a task is a challenge and using the ideas of each other brings them to come up with a mutual resolution and the achievement of the task. Nowadays theoretical development and research has rested largely a new trend that is emerging within the organizations as an essential process of teamwork. Teamwork has brought a new move in the research and development to the inputs and outputs that bound, constrain and impact on the team processes within organizations said Ilgen, D.R. (1999). The world is changes fast, any one set of instructions can’t be sufficient, changes needs flexible members, teams and organizations so as to be effective on task. This paper suggests that in teams members must use the exclusive human abilities. Cannon B.et al (1995) has précised dimensions of teams into three categories: Team dimensions 1-Cognitions: include associations, task team-mate characteristics, team mission, objectives, norms, and resources, team role interaction patterns, skills, roles, and team orientation. 2-Skills: consist on adaptability, shared situational awareness and mutual concept to conflict resolution. 90 The Government 3-Attitudes: symbolize motivation, collective potency, shared vision, team cohesion, mutual trust, collective orientation and importance of. Teamsize Researchers have given different approvals about the best size of team as Katzenbachetet al (1993) suggested that the teams should comprise on a dozen or so members which are enough to achieve a task. Although seven is the best size of the team in the organizational practices said Scharf, A. (1989). Several views of researchers are expressed in the literatures and it is difficult to decide which better is because their opinions are based on their own observations. The team size matters in the proper output and performance however from an empirical research it is also difficult to decide the suitable team size and what to accept. This study suggests that team size has a practical link with efficacy such as few or many member shave impact on the performance but size matters. Proper size of team improves the performance maximum stated Campion M. A et al (1996).These different results are expected due to the fact that appropriate team size is required for task, environment and situation where team works. However, larger teams can also experience coordination problems that delay performance. Sheppard, J. A. (1993) expressed that the question of best team’s size is a complex one; more research is required on this topic to explain the impact of team size on given definite task. Literature Review Across many different organizations and industries teamwork is focused to increase the performance of employees’ their unity and also create work culture. Organizations those regularly develop new ideas or products using a project-based approach and assemble teams in order to focus responsibilities to achieve the object. Researchers have given dissimilar meanings of “teams”. Dyer W.G. (2007) said that “teams are groups of people who trust in cooperation, if members are expert the success of goal is more possible”. It is essential due to the problemsolving cooperation added from many minds of team members working on a resolution of problems. Team members contribute their thoughts together to make exclusive plans for dealing with problems and this unity enhance the result due to interaction, trust and teamwork. Teamwork means a "work done by several companions with each doing a part but all subordinating personal prominence to the efficiency of the whole" Merriam, (2012). In addition combined employees are expected less hostile to each other and accepting more of each other’s decisions. Unity of employees can increase the flow of work in organization. When employee’s working together as a team, they learn from each other that awareness is based on their personal experiences and from coworkers; Team Work 91 employees from different departments may acquire knowledge from each other. The main object for organizations is to hold the team effort to achieve output and quality; team is a key to achieve quality productivity. According to Maddux et al (2003) “some of the organizations have major benefits from the use of teamwork which are showed in the following chart: Benefits of Teamwork 1 Improving quality of work life for employees 2 Reducing absenteeism and increasing turnover 3 Increasing innovation and change 4 Improving organizational adaptability and flexibility A real team is mostly one where members are allowed to take decisions that how to complete task. That authority enables them to control the work process, decreases the outside control and increases the sense of duty for work. Team always feels superiority on workplace and they rely on each other’s being there. Plamínek (2008) said that “affiliation with teamwork gives member a sense of belonging, interaction and recognition of success”. These actions support to remove the sense of loneliness of team member in organization. Effective teams can also improve efficacy through communication and trust between the team members, quality of work and decrease in absenteeism contribute to positive impact on team. Involving employees in teamwork helps the organization remain open to new ideas.“The world of organizations is shifting individualism is out and collectivism is in, power is out, empowerment is in.” stated G. M. Parker (1998). This study discovers the experiences and difficulties of teamwork that employees and organizations are facing nowadays due to big transformation and enlarged globalization. In recent years a remarkable amendment has been emerged in the belief of team working organizations. The modern study has explored that the scope of teamwork have been appeared in system rooted in belief, and employees accept changes that denoting a modern organizational system. The organizations which are responsive to the changes appear to achieve greater satisfaction. Although it may be suggested that, the managers should assess the values and beliefs of their employees to play more dedicated role in the development of organization by making sprit to face the modern challenges. Organizational cultural is much significant and it has the excessive impact on the performance of organization and employees’ but it is quiet arguable topic that the culture of teamwork can be developed according to the requirement. It is difficult to specify the relationships and to assess the reliable set of values to use as they believed symbol across the entire organizations. This review study focus that 92 The Government there is a great influence of organizational culture on the assumptions, values, and beliefs on the individuals’ considerations, actions and performances and so is vice versa, through learning, and training process. However the researchers believe that the organizational setup aids to unite employees of diverse cultures and dissimilar social backgrounds, traditions and have their own beliefs to work. Creating a positive teamwork culture it has several diverse aspects are goal setting, conflict resolution, empowerment, ability to accomplish tasks, measuring output and consideration for other teamwork cultures stated Pack L, et al April 27, (2012). Team work in the organization delivers employees the wisdom of unity; understand to each other’s, and reducing conflict. In addition teamwork in organization inspires employee for impartiality by affirming that no one is ignored in the organization and all treated equally. It is known that a team in organization is bound and sincere to work with dedication to bring the success. If the employees are committed and recognize the teamwork values and its benefits, as a part of the organization they can contribute a lot to the achievement of organization. One can finds the informal instances of team at these level, family, society, community, tribe and work groups etc., and formally team appears at the level of departments, functional groups, and other organizational units. The employees feel a greater sense of achievement for being a part of an organization, if they attain team work, having freedom to work not forced. The system gives best performance to achieve recognition and credit from their managers and it will increase their effort that helps them to contribute the organizational performance. Each team batter knows about their role and how to achieve tasks. The true spirit of teamwork gives benefit to organization in maintaining its standard by which it becomes identified. The team defines its specialty, and the way it is doing task that is perceived by the organization as well as its managers and it is secured by appreciation. Employees identify what they believe; that exist in their belief system and those understandings call them to change their views to develop and raise attention towards batter performance. The literature contains sufficient definitions of teamwork and the word team is used to denote a set of generally developed as to learn collective values, attitudes and cooperation to work. The study praises that the teamwork is mostly related with the team success for instance, Wagner (1995) described that “in the team individual is less valued and group is more valued, with”. It is found in the study that individualismcollectivism both regulates the relationships between team size, standing, and cooperation that have better effects on the cooperation of individualists rather than the cooperation of collectivists. Team Work 93 Conclusion The main concentration of this research paper is to examine more in-depth the fundamental of teamwork and its effectiveness to achieve the organizational goals. Teamwork provides vast amounts of knowledge and information, cultural differences each of these building a culture of teamwork and the skill to make the valuable solutions of the problems. To work efficiently, team members need a good understanding of how to do their job, to achieve goal and for that a basic way to ensure understanding is training, then they have to be motivated to do a job. Team is a vital activity of organization, when organization desires to perform sound it has to be confident that team functions effectively. Consequently it is compulsory to know how team performs, what manners within a team happen, and how they make decisions. If there is knowhow of teamwork events, it can be effective for the tasks that they have to accomplish. Organizations build up their own culture through tradition, history and structure these values can be accepted by team workers of an organization. The values and assumptions are the vital tools of organizations and are used as guidance for team. These have to do mostly with the basic dignity and worth of all members of team and the ability, necessity for them to solve the problems and work for the positive change. Through this review study is concluded that there is a good impact of teamwork on the organizations doings and success. Subsequently in recently developed literature there is a great focus amongst the social scientists and scholars’ in their discussion on the above topic teamwork. The above study is also an evidence of little effort to assess the significance of teamwork in organizations success. teams in organizReview of Related Literature for Practical quantitative research by senior high school studentsFind out information look up new words revise for the exam be absent from school do projects,do experiments,do research be keen on, be interested in, be fond of note down, catch up with, fall behind, hand in be upset about, belong to, disagree with, be bored with, borrow from