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React (Day-1)
Quiz by Khemraj Shrestha
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âReact is...
A programming language for mobile app development.
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A database management system.
A server-side scripting language.
âReact is not open source...
React is...
React is not open source...
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Owls, 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 biologyâthe 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 organismâs 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 (Owlâs 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 lifeâs 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 owlâs ner- vous system is made up of a brain, sense organs, nerve cells, and other parts that sense and respond to the owlâs surroundings. Organ systems are made up of organs. Organs are structures that carry out specialized jobs within an organ system. An owlâs 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 stimulusâa 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 âsmall room,â or âhutâ 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 cellâs 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 doesnât 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 owlâs temperature is maintained at about 40°C (104°F). To keep a constant temperature, an owlâs cells burn fuel to produce body heat. In addition, an owlâs feathers can fluff up in cold weather. In this way, they trap an insulating layer of air next to the birdâs 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 sunâs energy to generate sugar molecules during a process called photosynthesis. Some organisms depend on obtaining food energy from other organisms. For instance, an owlâs 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 frogsâ 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 booksâgenesâthat 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 frogâs sperm can fertilize a femaleâs 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 personâs 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 donât 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 âtree of lifeâ 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- vidualâs 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 âtreeâ 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 researcherâs conclusions. SECTION 3 OBJECTIVES â Outline the main steps in the scientific method. â Summarize how observations are used to form hypotheses. â List the elements of a controlled experiment. â Describe how scientists use data to draw conclusions. â Compare a scientific hypothesis and a scientific theory. â 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 questionâhypotheses. 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 preyâs 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 mouseâs 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 preyâs 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 mouseâs 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 owlâs strike relative to each mouseâs 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 owlâs 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 teacherâs 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 owlâs strike to the mouseâs head. Testing the Experiment Some controlled experiments are conducted âblind.â 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 variableâthe dependent variable. This measurement provides quantitative data, data measured in numbers. For example, in the experiment above, scientists mea- sured the distance of an owlâs strike from the preyâs head in cen- timeters, as shown in step of Figure 1-9. An eventâs 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 owlâs strike relative to the mouseâs 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 mouseâs 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 âtheoryâ in a different way than scientists use the word. People may say âItâs just a theoryâ 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 owlâs 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 âspend a great deal of time at a lab bench running analysis after analysis.â Many of the methods used in animal forensics, such as DNA sequenc- ing, are also used in human forensics. Education and Skills âą High schoolâthree years of science courses and four years of math courses. âą Collegeâbachelor of science in biol- ogy, including course work in zoology and genetics, plus experience in per- forming DNA analyses. âą Skillsâpatience, 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, âitâs just a theoryâ misleading? 6. Give another example of a conflict of interest. CRITICAL THINKING 7. Making Hypotheses On a nocturnal owlâs 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 owlâs 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 otherâs 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 drugâs 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 drugâs 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 siteâs 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 âdot govâ or .gov), by educational institutions (ends in âdot eduâ or .edu), by organizations (ends in âdot orgâ or .org), or by commercial businesses (ends in âdot comâ 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 siteâs 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 natureâs 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 â List the function of each of the major parts of a compound light microscope. â Compare two kinds of electron microscopes. â Describe the importance of having the SI system of measurement. â 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 objectâs 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 specimenâs 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 cellsA BAD CASE OF THE STRIPES By David Shannon Parts(18): Camilla Narrator 1 Narrator 2 Narrator 3 Narrator 4 Mr. Harms Mother Father Dr. Bumble Old Woman Environmental Therapist Dr. Grop Dr. Gourd Dr. Sponge Mr. Mellon Dr. Cricket Dr. Young <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> Narrator 1: A BAD CASE OF THE STRIPES By David Shannon Narrator 2: Camilla Cream loved lima beans. But she never ate them. Narrator 3: All of her friends hated lima beans, and she wanted to fit in. Camilla always worried about what other people thought of her. Narrator 4: Today she was fretting even more than usual. It was the very first day of school, and she couldn't decide what to wear. There were so many people to impress! Narrator 1: She tried on forty-two outfits, but none seemed quite right. She put on a pretty red dress and looked in the mirror. Then she screamed. Narrator 2: Her mother ran into the room, and she screamed, too. Mother: "Oh my heavens! You're completely covered with stripes!" Narrator 3: she cried. This was certainly true. Camilla was striped from head to toe. She looked like a rainbow. Narrator 4: Mrs. Cream felt Camilla's forehead. Mother: "Do you feel all right?" Narrator 1: she asked. Camilla: "I feel fine, but just look at me!" Narrator 2: Camilla answered. Mother: "You get back in bed this instant. You're not going to school today." Narrator 3: her mother ordered. Camilla was relieved. She didn't want to miss the first day of school, but she was afraid of what the other kids would say. And she had no idea what to wear with those crazy stripes. Narrator 4: That afternoon, Dr. Bumble came to examine Camilla. Dr. Bumble: "Most extraordinary! I've never seen anything like it! Are you having any coughing, sneezing, runny nose, aches, pains, chills, hot flashes, dizziness, drowsiness, shortness of breath, or uncontrollable twitching?" Narrator 1: he asked. Camilla: "No, I feel fine." Narrator 2: Camilla told him. Dr. Bumble: "Well then, I don't see any reason why she shouldn't go to school tomorrow. Here's some ointment that should help clear up those stripes in a few days. If it doesn't, you know where to reach me." Narrator 3: Dr. Bumble said, turning to Mrs. Cream. And off he went. Narrator 4: The next day was a disaster. Everyone at school laughed at Camilla. They called her "Camilla Crayon" and "Night of the Living Lollipop." Narrator 1: She tried her best to act as if everything were normal, but when the class said the Pledge of Allegiance, her stripes turned red, white, and blue, and she broke out in stars! Narrator 2: The other kids thought this was great. One yelled out, Narrator 3: "Let's see some purple polka dots!" Narrator 4: Sure enough, Camilla turned all purple polka-dotty. Someone else shouted, Narrator 1: "Checkerboard!" Narrator 4: and a pattern of squares covered her skin. Soon everyone was calling out different shapes and colors, and poor Camilla was changing faster than you can change channels on a T.V. Narrator 2: That night, Mr. Harms, the school principal, called. Mr. Harms: "I'm sorry, Mrs. Cream, I'm going to have to ask you to keep Camilla home from school. She's just too much of a distraction, and I've been getting phone calls from the other parents. They're afraid those stripes may be contagious." Narrator 3: he said. Camilla was so embarrassed. She couldn't believe that two days ago everyone liked her. Now, nobody wanted to be in the same room with her. Narrator 1: Her father tried to make her feel better. Father: "Is there anything I can get you, sweetheart?" Narrator 2: he asked. Camilla: "No, thank you," Narrator 3: sighed Camilla. What she really wanted was a nice plate of lima beans, but she had been laughed at enough for one day. Dr. Bumble: "Hmm, well, yes, I see. I think I'd better bring in the Specialists. We'll be right over.â Narrator 4: said Dr. Bumble to Mr. Cream on the phone. About an hour later, Dr. Bumble arrived with four people in long white coats. He introduced them to the Creams. Dr. Bumble: "This is Dr. Grop, Dr. Sponge, Dr. Cricket, and Dr. Young." Narrator 1: Then the Specialists went to work on Camilla. They squeezed and jabbed, tapped and tested. It was very uncomfortable. Dr. Grop: "Well, it's not the mumps." Dr. Sponge: "Or the measles." Dr. Cricket:"Definitely not chicken pox." Dr. Young: "Or sunburn." Narrator 2: replied the Specialists. Specialists:"Try these. Take one of each before bed." Narrator 4: said the specialists. They each handed her a bottle filled with different colored pills. Then they filed out the front door followed by Dr. Bumble. Narrator 1: That night, Camilla took her medicine. It was awful. Narrator 2: When she woke up the next morning, she did feel different, but when she got dressed, her clothes didn't fit right. She looked in the mirror, and there, staring back at her, was a giant, multi-colored pill with a face on it. Narrator 3: Dr. Bumble rushed over as soon as Mrs. Cream called. But this time, instead of the Specialists, he brought the Experts. Narrator 4: Dr. Gourd and Mr. Mellon were the finest scientific minds in the land. Once again, Camilla was poked and prodded, looked at and listened to. Narrator 1: The Experts wrote down lots of numbers. Then they huddled together and whispered. Dr. Gourd finally spoke. Dr. Gourd: "It might be a virus," Narrator 2: he announced with authority. Suddenly, fuzzy little virus balls appeared all over Camilla. Mr. Mellon: "Or possibly some form of bacteria," Narrator 3: said Mr. Mellon. Out popped squiggly little bacteria tails. Dr. Gourd: "Or it could be a fungus," Narrator 4: added Dr. Gourd. Instantly, Camilla was covered with different colored fungus blotches. The experts looked at Camilla, then each other. Experts: "We need to go over these numbers again back at the lab. Weâll call you when we know something," Narrator 1: said the Experts. But the Experts didn't have a clue, much less a cure. Narrator 2: By now, the T.V. news had found out about Camilla. Reporters from every channel were outside her house, telling the story of "The Bizarre Case of the Incredible Changing Kid." Narrator 3: Soon a huge crowd was camped out on the front lawn. Narrator 4: The Creams were swamped with all kinds of remedies from psychologists, allergists, herbalists, nutritionists, psychics, an old medicine man, a guru, and even a veterinarian. Narrator 1: Each so-called cure only added to poor Camilla's strange appearance until it was hard to even recognize her. She sprouted roots and berries and crystals and feathers and a long furry tail. But nothing worked. Narrator 2: One day, a woman who called herself an Environmental Therapist claimed she could cure Camilla. She said, Environmental Therapist: "Close your eyes, breathe deeply, and become one with your room." Camilla: "I wish you hadn't said that," Narrator 3: Camilla groaned. Slowly, she started to melt into the walls of her room. Her bed became her mouth, her nose was a dresser, and two paintings were her eyes. The therapist screamed and ran from the house. Mother: "What are we going to do? It just keeps getting worse and worse!" Narrator 4: cried Mrs. Cream. She began to sob. Narrator 1: At that moment, Mr. Cream heard a quiet little knock at the front door. He opened it, and there stood an old woman who was just as plump and sweet as a strawberry. Old Woman: "Excuse me, but I think I can help." Narrator 2: she said brightly. Narrator 3: She went into Camilla's room and looked around. Old Woman: "My goodness, what we have here is a bad case of the stripes. One of the worst I've ever seen!" Narrator 4: she said with a shake of her head. She pulled a container of small green beans from her bag. She said, Old Woman: "Here. These might do the trick." Mother: "Are those magic beans?" Narrator 1: asked Mrs. Cream. The old woman replied, Old Woman: "Oh my, no, there's no such thing. These are just plain old lima beans. I'll bet you'd like some, wouldn't you?" Narrator 2: she asked Camilla. Camilla wanted a big, heaping plateful of lima beans more than just about anything, but she was still afraid to admit it. She said, Camilla: "Yuck! No one likes lima beans, especially me!" Old Woman: "Oh, dear, I guess I was wrong about you." Narrator 3: said the old woman sadly. She put the beans back in her bag and started toward the door. Narrator 4: Camilla watched the old woman walk away. Those beans would taste so good. And being laughed at for eating them was nothing, compared to what she'd been going through. She finally couldn't stand it. Camilla: "Wait! The truth is...I really love lima beans." Narrator 1: she cried. The old woman smiled, popping a handful of beans into Camilla's mouth, and said, Old Woman: "I thought so." Camilla: "Mmmmmmm," Narrator 2: said Camilla. Suddenly the branches, feathers, and squiggly tails began to disappear.Then the whole room swirled around. When it stopped, there stood Camilla, and everything was back to normal. Camilla: "I'm cured!" Narrator 3: she shouted. The old woman said, Old Woman: "Yes, I knew the real you was in there somewhere." Narrator 4: She patted Camilla on the head and went outside and vanished into the crowd. Narrator 1: Afterward, Camilla wasn't quite the same. Narrator 2: Some of the kids at school said she was weird, but she didn't care a bit. Narrator 3: She ate all the lima beans she wanted, and she never had even a touch of stripes again.Juneteenth is an important holiday in American history. It honors the day in 1865 when enslaved people in Texas found out they were free. This day marked a major milestone on the path to ending slavery throughout the U.S. On June 19, 1865, Major General Gordon Granger of the Union army arrived in Galveston, Texas. He informed the enslaved people of Texas about the Emancipation Proclamation. The Emancipation Proclamation was a speech made by President Abraham Lincoln two years earlier, on January 1, 1863. It stated that enslaved people in many of the southern states were now free. President Lincoln gave this speech during the height of the Civil War. But by the time the Union soldiers made it to Texas, the Civil War had ended. It took over two years for this message to reach the people still enslaved in Texas! More than 250,000 people celebrated their newfound freedom on June 19. Soon after, many of these freed people decided to migrate to northern states to start a new life. But they continued to celebrate Juneteenth year after year and to share this holiday with their community. In 1872, a group of formerly enslaved people raised money to buy 10 acres of land near Houston, Texas. They named this land âEmancipation Parkâ. To this day, many Americans celebrate Juneteenth in this park to remember their history. Texas also holds a special parade to celebrate this day. Thousands of people participate and enjoy learning and celebrating African American culture and history. They fly the Juneteenth flag. The Juneteenth flag has a white star that symbolizes freedom and new hope for African Americans. Juneteenth is a day to remember the triumphs and struggles of African Americans. Even though enslaved people in Texas learned of their freedom on Juneteenth, they still faced violence, discrimination and inequality. That is why Juneteenth celebrations are so important to many Americans. Juneteenth recognizes the hardships of gaining freedom and the importance of remembering Black history in the United States.What is a Hurricane, Typhoon, or Tropical Cyclone? The terms "hurricane" and "typhoon" are regionally specific names for a strong "tropical cyclone". A tropical cyclone is the generic term for a non-frontal synoptic scale low-pressure system over tropical or sub-tropical waters with organized convection (i.e. thunderstorm activity) and definite cyclonic surface wind circulation (Holland 1993). Tropical cyclones with maximum sustained surface winds of less than 17 m/s (34 kt, 39 mph) are usually called "tropical depressions" (This is not to be confused with the condition mid-latitude people get during a long, cold and grey winter wishing they could be closer to the equator). Once the tropical cyclone reaches winds of at least 17 m/s (34 kt, 39 mph) they are typically called a "tropical storm" or in Australia a Category 1 cyclone and are assigned a name. If winds reach 33 m/s (64 kt, 74 mph), then they are called: "hurricane" (the North Atlantic Ocean, the Northeast Pacific Ocean east of the dateline, or the South Pacific Ocean east of 160E) "typhoon" (the Northwest Pacific Ocean west of the dateline) "severe tropical cyclone" or "Category 3 cyclone" and above (the Southwest Pacific Ocean west of 160°E or Southeast Indian Ocean east of 90°E) "very severe cyclonic storm" (the North Indian Ocean) "tropical cyclone" (the Southwest Indian Ocean) Coriolis Effect The Coriolis Effectâthe deflection of an object moving on or near the surface caused by the planetâs spinâis important to fields, such as meteorology and oceanography. Storm Approaching Southeast Asia Because of the Coriolis Effect, hurricanes spin counterclockwise in the Northern Hemisphere, while these types of storms spin clockwise in the Southern Hemisphere. This Northern Hemisphere storm, approaching Southeast Asia, is spinning counterclockwise. Earth is a spinning planet, and its rotation affects climate, weather, and the ocean through the Coriolis Effect. Named after the French mathematician Gaspard Gustave de Coriolis (born in 1792), the Coriolis Effect refers to the curved path that objects moving on Earthâs surface appear to follow because of the spinning of the planet. As Earth turns, points near the equatorâcountries like Ecuador and Kenyaâare moving much faster than places near the planetâs poles. This is because Earth is shaped like a marble: Its circumference is larger near its middle (the equator) than near its top and bottom. All places on Earth experience a day that is about 24 hours long, but points near the equator have to travel longer distances in the same period of time, which means that those places move faster. Scientists say these points have more âangular momentum.â This is why rockets are usually launched from places near the equator, like Cape Canaveral, Florida, United States. Such locations give rockets a large initial speed, which helps them get into orbit using the least possible amount of fuel. The Coriolis Effect influences wind patterns, which in turn dictate how ocean currents move. Imagine wind near the equator flowing to the north. That wind starts with a certain speed due to Earthâs rotation (near the equator, Earth rotates at a speed of roughly 1,600 kilometers per hour (1,000 miles per hour) from west to east). As the wind travels north toward the North Pole, it moves over parts of Earth that are rotating progressively more slowly. Since the wind retains its angular momentum, it keeps moving from west to east, overtaking the part of Earth turning more slowly below it. As a result, the wind appears to bend to the east (that is, to the right). This is the Coriolis Effect in action. Wind flowing south from the equator would likewise bend to the east. This effect is responsible for many meteorological and oceanographic phenomena. For instance, due to the Coriolis Effect, hurricanes in the Northern Hemisphere spin in a counterclockwise direction, while hurricanes in the Southern Hemisphere (known as cyclones) spin in a clockwise direction. Ocean-circling currents known as âgyresâ also spin in spiral patterns thanks to the Coriolis Effect. There is an urban legend that water in toilets spins in opposite directions in the Northern and Southern Hemispheres because of the Coriolis Effect. But that isn't trueâa toilet bowl is too small for the effect to be observed. Instead, other factors like the shape of the toilet bowl and the direction that the water enters are largely responsible for how the flushing water moves.Communication is the process of passing information, news, ideas or feelings from one person to another. For communication to take place, there must be a sender and a receiver of the message. System of communication is the different ways in which messages are sent and received. THE FOLLOWING ARE THE MAIN MEANS OF COMMUNICATION: 1.Traditional means: These are the means used to pass ideas or information in the past. The following are the various means used: Drumming, Message Carrier, Town Criers, Smoke Signal, Gun Shots, sending of symbolic items (such as a gun or bullets to announce war, Sponge and Soap to announce the safe delivery of a pregnant woman). 2. Modern means: These are the means used to pass ideas or information in the present day. The following are the various means used: Radio, Television, Telephone, Newspapers and Magazines, The Internet, Fax machine, Handsets, Telegram, Satellite, Road signs, Posters and billboards. DIFFERENCES BETWEEN TRADITIONAL AND MODERN MEANS OF COMMUNICATION. Traditional means Modern means 1.It makes use of local items such as drum, gong etc. It makes use of modern technology 2.Messages cannot travel very long distances. Messages can travel far and wide. 3. Delivery of message is slow. It may take days or weeks or months. Delivery of message is faster. Can reach the recipient within seconds. 4. It is cheaper It is very expensive. 5.It does not use electricity. It uses electricity. A recipient is the person or people receiving a message. While the sender is the person or people who sends the message.GUIDELINES ON THE ESTABLISHMENT AND IMPLEMENTATION OF THE RESULTS-BASED PERFORMANCE MANAGEMENT SYSTEM IN THE DEPARTMENT OF EDUCATION I. Rationale 1. The Civil Service Commission (CSC), through the issuance of Memorandum Circular (MC) No. 06, series of 2012, sets the guidelines on the establishment and implementation of the Strategic Performance Management System (SPMS) in all government agencies. The SPMS gives emphasis to the strategic alignment of the agencyâs thrusts with the day-to-day operation of the units and individual personnel within the organization. It focuses on measures of performance vis-a-vis the targeted milestones, and provides a credible and verifiable basis for assessing the organizational outcomes and the collective performance of the government employees. 2. As a learner-centered institution, the Department of Education (DepEd) is committed to continuously improve itself to better serve the Filipino learners and the community. The adoption of the SPMS in DepEd strengthens the culture of performance and accountability in the agency, with the DepEdâs mandate, vision and mission at its core. 3. There is a need to concretize the linkage between the organizational thrusts and the performance management system. It is important to ensure organizational effectiveness and track individual improvement and efficiency by cascading the institutional accountabilities to the various levels, units and individual personnel, as anchored on the establishment of a rational and factual basis for performance targets and measures. Finally, it is necessary to link the SPMS with other systems relating to human resources and to ensure adherence to the principle of performance-based tenure and incentives. 4. In view of the above, this Order aims to adopt the SPMS as the Results-based Performance Management System (RPMS). II. Scope of Policy 5. This DepEd Order provides for the establishment and implementation of the RPMS in all DepEd schools and offices, covering all officials and employees, school-based and non school-based, in the Department holding regular plantilla positions. It stipulates the specific mechanisms, criteria and processes for the performance target setting, monitoring, evaluation and development planning. IV. Policy Statement 9. The DepEd hereby sets the guidelines on the establishment and implementation of the Results-based Performance Management System (RPMS) in the Department, stipulating the strategies, methods, tools and rewards for assessing the accomplishments vis-a-vis the commitments. This will be used for measuring and rewarding higher levels of performance of the various units and development planning of all personnel in all levels. 10. For non school-based personnel, the RPMS shall provide for an objective and verifiable basis for rating and ranking the performance of units and individual personnel in view of the granting of the Performance-Based Bonus (PBB) starting 2015. 11. For school-based personnel, the RPMS shall be used only as an appraisal tool, which shall be the basis for training and development. The granting of PBB shall be governed by the existing PBB guidelines. 12. The Department shall adopt the RPMS framework shown in Annex B. 13. The DepEd RPMS shall follow the four-stage performance management system cycle as prescribed by the CSC: i. Performance planning and commitment (Phase I); ii. Performance monitoring and coaching (Phase II); iii. Performance review and evaluation (Phase III); and iv. Performance rewarding and development planning (Phase IV). V. Performance Cycle/Process 14. The RPMS shall align the performance targets and accomplishments with the Departmentâs mandate, vision, mission and strategic goals. It shall ensure 100% results orientation vis-a-vis the planned targets. On the other hand, the rateeâs demonstration of the required competencies shall be monitored for developmental purposes only. 15. The RPMS cycle shall cover performance for one whole year. All school-based personnel shall follow a performance cycle starting in April of the current year and ending in March of the following year; while non school-based personnel shall follow a performance cycle starting in January and ending in December. Annexes C and D illustrate the performance cycles which shall apply to school-based and non school-based personnel, respectively. 16. The performance planning and commitment shall be done prior to the beginning of the performance cycle; while the performance monitoring and coaching shall take place immediately after Phase I, and continue throughout the performance cycle. The performance review and evaluation, as well as the performance rewarding and development planning shall be done at the end of the performance cycle. A. Phase I: Performance Planning and Commitment 17. The performance planning and commitment shall be done prior to the start of the performance cycle where the rater meets with the ratee to discuss and agree on the following: i. Office KRAs, Objectives and Performance Indicators as anchored to the overall organizational outcomes; and ii. Individual KRAs, Objectives and Performance Indicators as anchored to the Office KRAs and Objectives. 18. The Office Performance Commitment and Review Form (OPCRF) shall be accomplished by the head of office to reflect the Office KRAs, Objectives and Performance Indicators. The head of office, in coordination with the Planning Office, shall ensure alignment of the office plans and commitments to the overall organizational outcomes. The OPCRF shall be equivalent to the IPCRF of the head of office. A sample of the filled out OPCRF, including the instructions for accomplishing the form, is shown in Annex E. 19. The Individual Performance Commitment and Review Form (IPCRF) shall be accomplished by the individual personnel to reflect the agreed Individual KRAs, Objectives and Performance Indicators. A sample of the filled out IPCRF, including the instructions for accomplishing the form, is shown in Annex F. 20. Defining the Key Result Areas. The head of office, in coordination with the Planning Office, shall define the office KRAs as anchored on the overall organizational outcomes. The rater and the ratee shall discuss and agree on the break down of the office KRAs into individual KRAs. Three (3) to five (5) KRAs shall be defined for each office and individual employee. KRAs are broad categories of general outputs or outcomes. It is the mandate or function of the office and/or individual employee. The KRA is the reason why an office and/or job exist. It is an area where the office and/or individual employee are expected to focus on. 21. Setting the Objectives. The head of office shall set three (3) objectives per office KRA. The rater and the ratee shall discuss and agree on three (3) objectives per individual KRA. Objectives are specific tasks, which an office and/or employee need to do to achieve their specific KRAs. In objective setting, the SMART criteria, which stands for Specific, Measurable, Attainable, Relevant, Time Bound, shall be applied. The SMART criteria are illustrated in Annex G. 22. Setting the Timeline. The timeline shall define the target date for accomplishing each of the Objectives. The timeline for the office Objectives shall be set by the head of office in coordination with the Planning Office and School Planning Team; while the timeline for the individual Objectives shall be discussed and agreed by the rater and the ratee. 23. Assigning the Weight. Assigning of weights shall be done per KRA. Weights for each office KRA shall be assigned by the head of office in coordination with the Planning Office; while the weights for each of the individual KRAs shall be discussed and agreed upon by the rater and the ratee. 24. Identifying the Performance Indicators. Using a five (5)-point rating scale, the head of office shall identify a performance indicator for each of the office objectives, while the rater and the ratee shall identify and agree on the performance indicator for each of the individual objectives. Performance indicators are exact quantification of objectives expressed through rubrics. They are assessment tools, which gauge whether a performance is positive or negative. In identifying the performance indicator, the operational definition or meaning of each numerical rating shall be indicated under each relevant dimension (i.e., quality, efficiency, or timeliness) per performance target or success indicator. This shall ensure that the rating is objective, impartial and verifiable. Table 1 below discusses the performance measures by which the indicator must satisfy. Table 1. Performance Measures CATEGORY DEFINITION Effectiveness/Quality The extent to which actual performance compares with targeted performance. The degree to which objectives are achieved and the extent to which targeted problems are solved. In management, effectiveness relates to getting the right things done. Efficiency The extent to which time or resources is used for the intended task or purpose. Measures whether targets are accomplished with a minimum amount or quantity of waste, expense, or unnecessary effort. Timeliness Measures whether the deliverable was done on time based on the requirements of the rules and regulations, and/or clients/stakeholders. Time-related performance indicators evaluate such things as project completion deadlines, time management skills and other time-sensitive expectations. Some Performances are only rated on quality and efficiency, some on quality and timeliness, and others on efficiency only. You need not use all three (3) categories. 25. Demonstration of Competencies. During Phase I, the rater shall discuss with the ratee the competencies required of the individual personnel. Competencies are defined as the knowledge, skills and behavior that individuals demonstrate in achieving oneâs results. Competencies shall uphold the DepEdâs core values. They represent the way individuals define and live the values. 26. DepEd shall adopt four classes of competencies as follows: i. Core behavioral competencies are competencies, which cut across the organization; ii. Leadership competencies are competencies intended for managerial positions; a. Third level officials b. Chiefs and Assistant Chiefs c. School Heads and Department Heads iii. Staff Core Skills are competencies intended for staff and teaching-related personnel; and iv. Teaching competencies are competencies intended for teachers. The DepEd-required competencies are illustrated in Annex I. 27. The rateeâs demonstration of the required competencies shall be monitored to effectively plan the interventions needed for behavioral and professional development. The assessment in the demonstration of competencies shall not be reflected in the final rating. 28. Reaching Agreement. Once the office and individual KRAs, Objectives and Performance Indicators are clearly defined, the rater and the ratee shall commit and reach an agreement by signing the OPCRF and IPCRF. The signed/approved OPCRF and IPCRF shall be the basis for monitoring and assessment, which shall take place in Phases II and III, respectively. B. Phase II: Performance Monitoring and Coaching 29. The performance monitoring and coaching shall commence after the rater and the ratee commit on the KRAs, Objectives and Performance Indicators, and sign the OPCRF and IPCRF. This shall be done throughout the year. 30. The two (2) main components of Phase II are the following: i. Performance monitoring; and ii. Coaching and feedback. 31. Performance monitoring shall provide key inputs and objective basis for rating. It shall facilitate feedback and provide evidence of performance. Performance monitoring shall be the responsibility of both the rater and the ratee who agree to track and record significant incidents through the use of the Performance Monitoring and Coaching Form (PMCF) shown in Annex J. Significant incidents are actual events and behaviors in which both positive and negative performances are observed and documented. 32. Coaching and feedback shall be a continuous process. Coaching and feedback shall be provided by the rater and/or shall be sought by the ratee to improve work performance and behavior. The rater, as the coach or mentor of the ratee, playing a critical role in the performance monitoring and coaching, shall provide an enabling environment and intervention to improve the office performance and to manage and develop individual potentials. 33. The PMCF shall capture the significant incidents. It shall provide a record of demonstrated behaviors, competencies and performance, and shall be an effective substitute in the absence of quantifiable data. The rater and the ratee shall sign each significant incident recorded in the PMCF to ensure that agreement has been reached. C. Phase III: Performance Review and Evaluation 34. The performance review and evaluation shall be done at the end of the performance cycle to assess the office and individual employeeâs performance level based on the commitments and measures as contained in the signed OPCRF and IPCRF. 35. A mid-year review is prescribed to determine the progress in achieving the Objectives. In exceptional cases, and only if the situation warrants, a one-time recalibration of office and individual Objectives shall be allowed during the mid-year review. Exceptional cases shall include instances when high level decisions are taken into effect such as changes in strategic directions, and circumstances beyond the control of the ratee such as natural and/or man-made calamities, including typhoon, earthquake and other fortuitous events. During the mid-year review, the rater shall inform in writing the ratee of the status of performance, in case of an Unsatisfactory or Poor performance. Coaching, feedback and appropriate interventions shall be provided where necessary. 36. The RPMS shall put premium on KRAs towards the realization of organizational vision, mission, strategic priorities and the OPIF logframe. Hence, rating for planned and/or intervening tasks shall always be supported by reports, documents or any output as proofs of actual performance. In the absence of said bases or proofs, a particular task shall not be rated and shall be disregarded. 37. Office and Individual Performance Assessment. The head of office, in coordination with the Planning Office, shall assess the performance of the office vis-a-vis the committed targets at the beginning of the performance cycle. The rater and the ratee shall discuss and agree on the individual assessment based on the actual accomplishments of each of the KRAs and Objectives. The final rating shall be based solely on the accomplishment of the specific objectives as measured by the Performance Indicators. The OPCRF and IPCRF shall be accomplished and completed by the rater and the ratee to: i. Reflect actual accomplishments and results; ii. Rate each of the objectives; iii. Compute for the score per objective; iv. Determine the overall rating for accomplishments; v. Reach an agreement; and vi. Assess the competencies. 38. Initial self-rating shall be encouraged prior to the rater-ratee discussion. 39. Third Level Officials, as heads of offices, shall accomplish the OPCRF for submission to the Planning Office. The individual assessment of Third Level Officials shall be contained in the CESPES Forms for submission to the Career Executive Service Board (CESB). The BHROD and Personnel Division shall be furnished a copy of both forms. 40. Actual Results. The rater and the ratee shall discuss and agree on the actual accomplishments and results based on the performance commitments and measures made at the beginning of the rating period. They shall evaluate each objective whether it has been achieved or not. The significant incidents as reflected in the PMCF shall be considered for the actual results. 41. Rating the Objectives. Based on the actual accomplishments and results, each of the Objectives shall be rated using the rating scale specified below: Table 2. The RPMS Rating Scale NUMERICAL RATING ADJECTIVAL RATING DESCRIPTION OF MEANING OF RATING 5 Outstanding Performance represents an extraordinary level of achievement and commitment in terms of quality and time, technical skills and knowledge, ingenuity, creativity and initiative. Employees at this performance level should have demonstrated exceptional job mastery in all major areas of responsibility. Employee achievement and contributions to the organization are of marked excellence. 4 Very Satisfactory Performance exceeded expectations. All goals, objectives and targets were achieved above the established standards. 3 Satisfactory Performance met expectations in terms of quality of work, efficiency and timeliness. The most critical annual goals were met. 2 Unsatisfactory Performance failed to meet expectations, and/or one or more of the most critical goals were not met. 1 Poor Performance was consistently below expectations, and/or reasonable progress toward critical goals was not made. Significant improvement is needed in one or more important areas. The final assessment shall correspond to the adjectival description of Outstanding, Very Satisfactory, Satisfactory, Unsatisfactory or Poor. The range of adjectival rating is as per attached in Forms A, B, and C. 42. Process for Computing the Score per KRA. i. The rater and ratee shall ensure that each KRA has been assigned weight according to priority. ii. As an option, the rater and ratee may assign weights to objectives which shall be equal to the total weight assigned to a particular KRA. KRA 1 â Weight assigned is 40% Objective 1 is 20% Objective 2 is 10% Objective 3 is 10% iii. The score per KRA shall be computed using the following formula: 43. Plus Factor. The plus factor shall be considered as another KRA. These are value adding accomplishments, which are not covered within the regular duties and responsibilities. The weight on the plus factor shall not exceed the weight of the highest mandated KRA. For teachers, the plus factor shall be limited to work/activities, which contribute to the teaching-learning process. 44. Determining the Overall Rating for Accomplishments. The overall rating/assessment for the accomplishments shall fall within the following adjectival ratings and shall be in three (3) decimal points: Table 3. Adjectival Ratings RANGE ADJECTIVAL RATING 4.500-5.000 Outstanding 3.500-4.499 Very Satisfactory 2.500-3.499 Satisfactory 1.500-2.499 Unsatisfactory below 1.499 Poor 45. Reaching Agreement. Upon determining the overall rating for the actual accomplishments and results, the rater and the ratee shall reach an agreement by signing the OPCRF and IPCRF. The average rating of individual staff members should not go higher than the collective performance assessment of the office. 46. Assessing the Competencies. The rater shall discuss with the ratee the set of competencies observed during the performance cycle. The competencies shall not be reflected in the final rating. Competencies shall be monitored for developmental purposes. In evaluating the individualâs demonstration of competencies, the rating scale in Table 4 shall apply: Table 4. The DepEd Competencies Scale SCALE DEFINITION 5 Role model 4 Consistently demonstrates 3 Most of the time demonstrates 2 Sometimes demonstrates 1 Rarely demonstrates 5 (role model) â all competency indicators 4 (consistently demonstrates) â four competency indicators 3 (most of the time demonstrates) â three competency indicators 2 (sometimes demonstrates) â two competency indicators 1 (rarely demonstrates) â one competency indicator D. Phase IV: Performance Rewarding and Development Planning 47. The results of the performance review and evaluation shall be used in performance rewarding and development planning. This phase shall be done after Phase III. 48. The rater shall discuss and provide qualitative comments, observations and recommendations in the individual employeeâs performance commitment, competency assessment and significant incidents which shall be used for training and professional development. These can be written under the strengths and development needs column of the Part IV-Development Plans of the IPCRF. 49. The rater and the ratee shall identify and discuss the individualâs strengths and development needs, and reflect them in the Part IV-Development Plans of the IPCRF. The competencies which the ratee demonstrated consistently and the areas, where the ratee meet or exceed expectations shall be referred to as the rateeâs strengths. The competencies, which the ratee rarely demonstrates and the areas where the ratee has room for improvement and has not met the expectations, shall be identified as the rateeâs development needs. Make a situational SOLO-based questions in the context of school leadershipReact (Day-2)Memory Adventure: From Learning to Forgetting Imagine Alex is preparing for a school science fair. Storing Memories (2.5) Alex studies a science experiment. The semantic memory (facts and knowledge, like âwater boils at 100°Câ) is stored in the brain, while episodic memory (personal experiences, like âI mixed vinegar and baking soda yesterdayâ) records the event. The hippocampus (the brainâs âsave buttonâ) helps transfer these memories into long-term memory. During sleep, memory consolidation (making memories stable and long-lasting) happens, and Alex vividly remembers the fun surprise when the mixture fizzesâa flashbulb memory (emotionally strong, vivid memory). Alex also learns the skill of carefully pouring liquids, a procedural memory stored in the basal ganglia, and how to react when the mixture splashes, a conditioned response stored in the cerebellum. Emotions make the memory even stronger, thanks to the amygdala. Retrieving Memories (2.6) The next day, Alex goes to the science fair. Seeing the experiment table triggers priming (unconscious memory activationâseeing the table makes Alex remember steps). Being in the same classroom helps context-dependent memory (better recall in the same place as learning). Alex is also in the same excited mood as while practicing, so mood-congruent memory helps remember details of the experiment. When listing the steps, Alex remembers the first step clearly and the last step best, thanks to the serial position effect. Using strategies like quizzing himself earlier (testing effect) and spacing study sessions (spacing effect) improves retrieval. Forgetting & Memory Errors (2.7) During the fair, Alex tries to remember an old trick learned last year, but some details are fuzzy. This is retroactive interference (new memories block old ones). At the same time, old steps from last year sometimes confuse him, an example of proactive interference (old memories block new info). Alexâs friend jokingly says he added glitter to the experiment last week. Alex later misremembers seeing glitterâthis is the misinformation effect. He even forgets where he first learned the correct steps, a case of source amnesia, and feels a strange sense of dĂ©jĂ vu when looking at a similar experiment table. Unfortunately, Alexâs cousin has anterograde amnesia (cannot form new memories) and can only remember things from before last year, while his neighbor has retrograde amnesia (loses past memories) and cannot recall last weekâs fair prep. Luckily, Alexâs strong study habits, sleep, and emotional engagement helped protect his memories from being forgotten too quickly.