Loading...

The conditions and nullifiers of prayer-Gr.3
Quiz by Feda Odeh
Customize this quiz to suit your class
Instantly translate to 100+ languages
Tag the questions with any skills you have. Your dashboard will track each student's mastery of each skill.
She stood praying while she was chewing food.
He speaks on the phone whilst praying.
She stood praying while she was chewing food.
He speaks on the phone whilst praying.
He prays in a place known to be clean.
He faces the Qiblah during prayer.
A girl prays wearing short clothes
Give this quiz to my class
Certainly, let's expand on each section in detail so you can learn more from the provided text: # Summary This text aims to explain various aspects related to technology, particularly focusing on a concept known as "Tech Disruption." It explores how technology affects different sectors, outlines the conditions for tech disruption, discusses the industrial revolutions, introduces the laws of disruption, and mentions factors influencing technology choices. ## Concept of Technology **Technology** encompasses a range of elements within organizations. It includes **expertise, equipment, and procedures** used to convert inputs, such as resources or raw materials, into outputs, which can be products or services. This involves various aspects, such as **product design, production techniques, quality assurance measures, human resource development, and management systems**. In essence, technology represents the tools and knowledge used to create and deliver goods or services effectively. ## What is Tech Disruption **Tech Disruption** refers to a phenomenon where smaller companies with limited resources successfully challenge well-established incumbent businesses. This disruption is primarily driven by **technology**, which acts as the catalyst, enabler, or even the sole reason behind the change. The significance of this concept lies in the fact that entrepreneurs must make careful and thoughtful decisions when it comes to adopting and investing in technology. **Why it's Important?** These decisions are crucial because they involve significant investments and will have a substantial impact on a company's ability to create, innovate, and operate its services in a sustainable and cost-effective manner. ## Four Main Impact **Tech Disruption** has four main impacts on businesses and industries: 1. **Shifting Customer Expectations**: As technology evolves, customer expectations change. Companies must adapt to meet these evolving demands to remain competitive. 2. **Enhanced Products Through Data**: Data-driven insights improve the productivity and efficiency of assets, leading to better products and services. 3. **New Partnerships and Collaboration**: Tech disruption encourages companies to form new partnerships and collaborations, recognizing the importance of working together to stay relevant. 4. **Transformation of Operating Models**: Traditional operating models are being transformed into digital models, where technology plays a central role in how businesses operate and deliver value. ## The 11 Macro Sources of Distribution The **11 Macro Sources of Distribution** represent various factors that influence the distribution of resources and opportunities in society. These factors include: 1. **Wealth Distribution**: How wealth is distributed among individuals and entities. 2. **Education**: The availability and quality of education opportunities. 3. **Infrastructure**: The state of infrastructure, such as transportation and communication networks. 4. **Government**: Government policies and regulations that impact resource distribution. 5. **Geopolitics**: Geopolitical factors, such as international relations and conflicts. 6. **Economy**: Economic conditions and trends, including markets and financial systems. 7. **Public Health**: The state of healthcare and public health systems. 8. **Demographics**: Characteristics of the population, such as age and gender. 9. **Environment**: Environmental factors and sustainability concerns. 10. **Media and Telecommunications**: The role of media and communication technologies. 11. **Technology**: Technological advancements and their impact on society. ## When Does Tech Disruption Happen? **Tech Disruption** occurs when specific conditions are met: ### Technology Is Mature Enough - **Technology Accessibility**: Technology must be accessible to a wide range of people and organizations. - **Critical Mass**: It should have reached a critical mass where it can create significant impact. - **Affordability**: Technology must be affordable for businesses to adopt. ### Sector Is Ready For Change - **Tech Infrastructure**: The sector should have the necessary technological infrastructure in place. - **Policy Framework**: A conducive policy framework is essential to support and regulate the use of technology. - **Lack of Disruption**: If the sector is stagnant or facing issues, it becomes ripe for tech disruption. ### Sector + Technology + Timing + Product - **Mature Technology with an Unready Sector**: If technology is mature but the sector is not ready, it can lead to building the wrong product based on incorrect assumptions. - **Unmatured Technology with a Ready Sector**: Conversely, if technology is not matured but the sector is ready, it may take longer to develop the product. ## Ready for Industri 5.0? This section briefly outlines the five industrial revolutions: 1. **Industri 1.0 (1784)**: Marked by mass production assembly lines using electrical power. 2. **Industri 2.0 (1870)**: Introduced mechanization, steam, and water power. 3. **Industri 3.0 (1969)**: Characterized by automated production, computers, IT systems, and robotics. 4. **Industri 4.0 (Present)**: Involves smart factories, autonomous systems, IoT (Internet of Things), and machine learning. 5. **Industri 5.0 (Future)**: Envisions mass customization and cyber-physical cognitive systems. ## Three Laws of Disruption These laws explain the nature of disruption: 1. **Disruption Comes to All**: Disruption is a universal phenomenon; it affects all industries and businesses sooner or later. 2. **Product-Market Fit**: Disruption occurs due to changes in Product-Market Fit, which means aligning a product with its target market effectively. 3. **Methods to Change Product-Market Fit**: To address disruption, a company can change the product, the target market, or influence people's preferences regarding the product. ## The 40% Rule This rule provides a framework for evaluating the fit between a product and its market: - **Value Proposition**: The product should solve customers' problems effectively. - **Channels**: The product should be able to reach customers cost-effectively. - **Monetization**: Customers should be willing to pay for the product. ## PMF Framework: 5 Steps to Product/Market Fit The **PMF (Product/Market Fit) Framework** consists of five steps: 1. **Business Modeling**: Developing a business model that aligns with the market. 2. **Market Validation**: Confirming that there is demand for the product in the market. 3. **Customer Interviews**: Gaining insights from potential customers. 4. **Product Development and Customer Acquisition**: Creating the product and acquiring customers. 5. **Product Analytics**: Using data to determine if the product has achieved Product/Market Fit. ## Factors Determining the Choice of Technology Several factors influence the choice of technology: 1. **Government Policy**: Government regulations and policies can encourage or restrict the adoption of specific technologies. 2. **Available Resources**: The resources, both financial and human, impact the adoption of technology. 3. **Technological Capability**: The organization's technological capabilities influence the choice of technology. 4. **Existing Technological Level**: The current technological state of the industry or organization plays a role. 5. **Institutional Arrangement**: Organizational structures and arrangements affect technology choices. ## Conclusion In conclusion, the text emphasizes the critical role of technology in driving change and disruption in various industries. It highlights the need for informed decision-making when it comes to technology investments, as well as the conditions necessary for tech disruption to occur. Understanding the historical context of industrial revolutions, the laws of disruption, and the factors influencing technology choices is essential in today's fast-paced and tech-driven business environment. Embracing technology disruption is crucial for transforming business models and adapting to evolving market dynamics.
If we look at the United States on a map today, it is very difficult to imagine that where we see borders, cities, and states, there once existed nothing but open land, uncharted mountain ranges, and miles of untouched wilderness. North America was a highly desired destination for exploration and settlement for Europeans. In the early 1500s, expeditions from Europe to North America were funded by Europe's kings and queens in hopes of expanding their territories across the world. The voyages were treacherous with unknown dangers and many attempts to settle in this new land were faced with failure. In the early 1600’s however, the settlers of Jamestown and Plymouth survived the harsh conditions and established the first two permanent English settlements in North America. Jamestown Colony in Virginia Jamestown was founded in 1607. Of course, its colonists did not know it would go on to become the the first permanent English settlement in the Americas. The settlement was located along the James River off Chesapeake Bay in modern-day Virginia. Life in Jamestown was very hard, and nearly 80% of the first settlers died in the first year due to disease and starvation. The region was warm and had fertile soil, making it a perfect place for growing crops, specifically tobacco. Sponsored by a joint stock company known as the Virginia Company of London, Jamestown was originally established as a profit-making enterprise. The first settlers looked for gold and other natural resources that could bring a profit to the company's investors. After several very difficult years, the colonists were eventually able to grow tobacco that was popular in England and it became a valuable cash crop. Jamestown's colonists were primarily all supporters of the Church of England and felt a strong connection to their homeland. Many, like John Smith, returned to England, or would move back and forth between the two locations. Being that Jamestown was founded by a corporation looking to make a profit, it began using enslaved labor in 1619. Indentured servants and enslaved Africans made up much of the workforce on the growing tobacco and cotton plantations. The system of using enslaved Africans for the profit of American plantations has been described as America's "original sin". About 400 miles to the north of Jamestown, a group of Pilgrims seeking religious freedom established Plymouth in 1620 as the second English colony in North America. Located in modern day Massachusetts, the colder climate and rocky soil made farming and agriculture more difficult. Instead of growing cash crops, settlers turned to lumber, shipbuilding, and fishing for trade. Unlike the settlers of Jamestown, the Pilgrims of Plymouth Colony were dissenters from the Church of England. They came to the New World so that they could freely practice their religion without fear of persecution. Although their reasons for settling were different, the settlements had many similar experiences. Jamestown and Plymouth both faced harsh and demanding climates and struggled with hunger, disease, and death. In their first years they had much difficulty establishing housing and finding a sustainable source of food. Plymouth Colony in New England While the settlers in Jamestown used the House of Burgesses as a legislative body for laws and decisions, the Pilgrims in Plymouth wrote and agreed to the Mayflower Compact as a set of rules for self-government. Both helped maintain the rule of law in new places far from the courts and tradition of England. Settlers of both colonies experienced complicated and, at times, violent relationships with local Native Americans that owned the land. While some American Indian groups offered help to the new settlers, oftentimes both sides needed to defend themselves from attacks. Nevertheless, the settlers of Jamestown and Plymouth persevered through these difficulties and maintained their establishments, providing inspiration for future colonies and settlers in search of a new life in the New World.
Escape from Unsuitable Conditions Some species can survive unfavorable environmental conditions by escaping from them temporarily. For example, desert animals usually hide underground or in the shade during the hottest part of the day. Many desert species are active at night, when temper- atures are much lower. A longer-term strategy is to enter a state of reduced activity, called dormancy, during periods of unfavorable conditions, such as winter or drought. Another strategy is to move to a more favorable habitat, called migration. An example of migration is the seasonal movements of birds, which spend spring and summer in cooler climates and migrate to warmer climates in the fall. THE NICHE Species do not use or occupy all parts of their habitat at once. The specific role, or way of life, of a species within its environment is its niche (NICH). The niche includes the range of conditions that the species can tolerate, the resources it uses, the methods by which it obtains resources, the number of offspring it has, its time of reproduction, and all other interactions with its environment. Parts of a lion’s niche are shown in Figure 18-6. Generalists are species with broad niches; they can tolerate a range of conditions and use a variety of resources. An example of a generalist is the Virginia opossum, found across much of the United States. The opossum feeds on almost anything, from eggs and dead animals to fruits and plants. In contrast, species that have narrow niches are called specialists. An example is the koala of Australia, which feeds only on the leaves of a few species of eucalyptus trees. Some species have more than one niche within a lifetime. For example, caterpillars eat the leaves of plants, but as adult butter- flies, they feed on nectar. Plants and animals are able to share the same habitats because they each have different niches. FIGURE 18-6 niche from the Old French nichier, meaning “to nest” Word Roots and Origins www.scilinks.org Topic: Niche/Habitats Keyword: HM61029 mb06se_iecs02.qxd 5/24/07 10:25 AM Page 365 366 CHAPTER 18 ENERGY TRANSFER All organisms need energy to carry out essential functions, such as growth, movement, maintenance and repair, and reproduction. In an ecosystem, energy flows from the sun to autotrophs, then to organisms that eat the autotrophs, and then to organisms that feed on other organisms. The amount of energy an ecosystem receives and the amount that is transferred from organism to organism affect the ecosystem’s structure. PRODUCERS Autotrophs, which include plants and some kinds of protists and bacteria, manufacture their own food. Because autotrophs cap- ture energy and use it to make organic molecules, they are called producers. Recall that organic molecules are molecules that con- tain carbon. Most producers are photosynthetic, so they use solar energy to power the production of food. However, some autotrophic bacteria do not use sunlight as an energy source. These bacteria carry out chemosynthesis (KEE-moh-SIN-thuh-sis), in which they use energy stored in inorganic molecules to produce carbohydrates. In terres- trial ecosystems, plants are usually the major producers. In aquatic ecosystems, photosynthetic protists and bacteria are usu-
Classification of plants • Plants can be classified as cultivated and wild plants. • Both cultivated and wild plants are very useful to people, animals and the environment. 1. Cultivated plants: • Cultivated plants are plants grown by people for selling. • They can be grown in the field, vegetable garden, home garden and orchard. Classification of plants 2. Wild plants Wild plants are plants that grow on their own outside the garden, orchard or field. They have many uses such as: • Food for people and animals • Shelter • Source of fuel in form of firewood. • Examples include, grasses, msasa, yellow wood, mahogany, mopane Plant Nutrition • The presence of plant nutrients in the soil make them grow well. • The three major plant nutrients are nitrogen, phosphorus and potassium. Sources of plant nutrients • The source for plant nutrients are grouped into organic and inorganic sources. Organic sources of plant nutrients • These are found in nature. • They are natural materials such, decayed plant and animal matter which include: • Animal manure from cattle, sheep, goats, poultry and pigs. • Green manure • Legume crops like beans, peas and groundnuts. • Humus • These material sources may also be called natural fertilizers. Inorganic sources of plant nutrients • These are sources of plant nutrients made by people in industries. They include: • Compound fertilizers like compound A, B, C and D. • These have two or more nutrients. • Straight fertilizers like ammonium nitrate, single super phosphate and urea. • A straight fertilizer supplies a single or more nutrient to the crop. A straight fertilizer A Compound fertilizer Sources of N,P,K • Ammonium nitrate and Urea- contain nitrogen Double super Phosphate, Single super phosphate-contain phosphorus • Muriate of Potash contains Potassium 2 . Compound fertilisers -have two or three of the three major plant nutrients (N.P.K). N-nitrogen P-phosphorus K-potassium Examples Compound D Wednesday 17 May 2023 Revision exercise (Plant nutrition) 1 .Name the 3 plant nutrients needed by plants. 2. What are the 2 groups of plant nutrients sources? 3. Give 3 examples of organic sources of plant nutrients. 4. What is a straight fertilizer? 5. Compound fertilizer supplies ……………or ………………. Nutrients. Vegetable crops • A vegetable is any part of a plant that is eaten by humans as food part of a meal. • Vegetables are grouped and named according to the part that is eaten. • These are leaf, root, fruit, flower, bulb, tuber and legume vegetables. Leaf vegetables Types of veg Legume etable cropsvegetables Fruit vegetables Root, bulb and tuber Flower vegetables Cabbage Peas Tomato Root: carrots Cauliflower Rape Green beans Pepper Parsnip broccoli Spinach Melons Beetroot Tsunga Cucumber Bulb: onion Lettuce Squash Garlic kale Egg plant Leek chillies Tuber: Irish potato Wednesday 31 May 2023 Vegetable crops 1. What is a vegetable? 2. Which one is not a vegetable from the list below? a. Covo B. cabbage C. wheat D. tomato 3. Choose a vegetable which is not a fruit vegetable. a. tomato B. pepper C. kale D. egg plant 4. From which pair of vegetables do we eat the flower? A. cauliflower and garlic B. broccoli and cauliflower C. broccoli and rape D. cauliflower and pepper 5. Give one example of a vegetable belonging to each of the following groups. a. root b. legume c. bulb 6. Name any 5 groups of vegetable classification according to the parts eaten. Growing leaf vegetables • Although there are many types of vegetables, the leaf, fruit and bulb vegetables are widely grown. • Leaf vegetables form the greater part of vegetable crops. • Leaf vegetables belong to a family called brassica. • Brassicas include cabbages, lettuce, spinach, covo and many others. • Each brassica family has got its own varieties called cultivar. • They usually grow under the same climatic conditions and are affected by the same pests and diseases. • The selection of a variety depends on the following : The intended use of the vegetable, for example, salad, stew or snacks. Days taken to mature. Disease resistant Season of the year Seedbed preparation • Brassica vegetables are usually raised in seedbeds. • The seedbeds are prepared by: • Marking the position of the bed 1 meter in width by any length using a tape measure, hammer and pegs. • Digging a seedbed to a depth of 25 to 30cm using a hoe. • Breaking lumps of soil using a garden rake. Soil requirements • Brassicas need: • Well drained soils. • Fertile soil for good growth • Slightly acidic soils (pH 5.5-6) Climatic requirements • Brassicas need cool to warm temperatures. • Very low temperatures cause cabbages to flower which is called bolting. • Brassicas can be grown throughout the year. Seedbed preparation • Brassica seedlings are usually raised in seedbeds. • A seedbed is prepared by: Marking the position of the bed 1 metre in width by any length using a tape measure, hammer and pegs. Digging a seedbed to depth of 25 to 30 cm using a hoe. Breaking lumps of soil using a garden rake. This is done in order to have a fine tilth and improve soil to seed contact. Making ridges that a 15cm high. Apply 3 to 5kg/m² of well decomposed manure. 60 to 100g/m² of compound fertilizer can be added into the soil. Management of vegetable crops • After transplanting the seedlings, the seedlings need to be looked after. (a)Controlling weeds: all vegetables must be kept weed free. • This is done either by hand pulling weeds or shallow cultivation using a hand fork. (b) Pest control: common pests that affect the brassicas are aphids and diamond black moth larva. • Aphids are small green insects that suck the juice from the leaves leaving them with curls. • They are controlled by spraying malathion using the instructions on the label. (c) Disease control: bacterial diseases are common in brassicas. • Common diseases are black rot and soft rot, especially in cabbages. • These are controlled by: Crop rotation Early planting Planting resistant cultivars (d) Top dressing: brassicas are top dressed using Ammonium Nitrate at a rate of 2.5g per plant. • Top dressing is usually done 3 or 4 weeks after germination. FIELD CROPS • Field crops are crops that are grown on a large piece of land. • Example of field crops: Maize Cotton Groundnuts Roundnuts Wheat Sunflower Tobacco Sugar cane Tea Coffee Soya beans sorghum Classification of field • Field crops can be classified according to use such crops cereal, fibre, sugar and oil. 1. Cereal crops: • A cereal is a grass grown for its edible seeds. • They are also known as grain crops. • The major cereal crops are maize, wheat, rice, barley, sorghum and millet. 2 . fiber crops : • these are crops which are grown for their fiber and are used in making textiles, ropes and rugs. • Important fiber crops are cotton, flax and sisal 3. Oil seed crops: • These crops are grown for the purpose of extracting oil from their seed. • The main oil seed crops are groundnuts, sunflower, soyabean and cotton seed. 4 . Sugar crops : • Sugar crops include sugarcane,
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 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 cells
HEALTH EDUCATION 3. SPECIFIC OBJECTIVES: Students should able to know about_______ 1. definition of health education 2. aims of health education 3. objectives of health education 4. principles of health education 5. scope of health education 6. planning of health education 7. steps in planning health education 8. levels of health education 9. doctors s responsibility 4. INTRODUCTION: Health education is a term frequently used by health care professional. its aims at individual and community health. Health education is the translation of what is known about health into desirable individual and community behaviour pattern by means of an education process. Definition: “A process aimed at encouraging people to want to be healthy , to know how to stay healthy, to do what they can individually and collectively to maintain health And seek help when needed”. OBJECTIVES - To inform people or disseminate scientific knowledge about prevention of disease and promotion of health - To motivate people to change their habits and lifestyle that are harmful to their health also motivate people to adopt habits and ways of living conducive to healthy living. - To guide the people who need help to adapt and maintain healthy practices and lifestyle by showing proper community resources. --- PRINCIPLES OF HEALTH EDUCATION - Credibility Of Message: It is the degree to which the message to be communicated is perceived as trustworthy by the receiver. - Creating interest among participants: It is a psychological principle that people are unlikely to listen to things that are not of their interest. If a health programme is based on the felt needs, people will participate in the programme willingly. - Motivating the participants: Motivation is like a petrol engine that drives the mental engine. It is the fundamental desire in every person to learn. Motivation is contagious; one motivated person may spread motivation throughout the group. 13. - Enhance comprehension of content: It means health education should be based on the level of understanding, education and literacy of people at whom the teaching is directed. Teaching should be within the mental capacity of the audience. - Ensure reinforcement: Repetition at intervals is necessary to promote learning. Without reinforcement and feedback, students can go back to the pre-awareness stage. - Encourage active participation: Health education should aim at encouraging people to work actively with health workers and others in identifying their own health problems and also in developing solutions. 14. - Learning by doing: Teaching is effective when individuals actively participate in health education. Learning becomes active and quicker if the individuals are made active physically as well as psychologically. - Known to unknown: The people in a community know something and the health educator enlarges this knowledge. If the health educator links new knowledge with the old knowledge, it can enhance learning. - Maintaining good human relations: Sharing of information, ideas and feelings happens most easily between people who have a good relationship. 15. - Setting an example: The health educators should set a good example in the topic they are dealing with as it fosters better understanding. - Regular feedback: Feedback is one of the key concepts of the system approach. The health educator can modify the elements of the system in light of the feedback from his audience. For effective communication, feedback is of paramount importance - Efficient leadership: Leaders are agents of change and they can be made use of in health education work. Psychologists have shown and established that we learn best from people we respect and regard. 16. The essential attributes of a leader are as follows - Understands the needs of the community. - Provides proper guidance. - Takes initiative. - Is receptive to the views and suggestions of people. - Identifies himself with the community. Is selfless, honest, impartial, considerate and sincere. - Is easily accessible to people. 17. SCOPE OF HEALTH EDUCATION 1. Nutrition 2. Hygiene 3. Family health 4. Disease prevention and cantrol 5. Psychological health 6. Prevention of accident 7. Use of health services 8. Human biology 19. - Nutrition: The aim of nutrition education is to guide people to choose optimum and balanced diets, remove prejudices and promote good dietary habits. nutrition education is a major intervention for the prevention of malnutrition, promotion of health and improving the quality of life. 20. - Hygiene: This has two aspects: personal and environmental. Personal: The aim of personal hygiene is to promote standards of personal cleanliness . Environmental: Has two aspects: Domestic and community. All environmental sanitation programmes should include health education 21. - Family health: The family is the first defence as well as the chief reliance for the well-being of its members. One of the main tasks of health education is to promote family self-reliance, especially regarding the family's responsibilities in child bearing, child rearing, self-care and in influencing their children to adopt a healthy lifestyle. 22. - Disease prevention and control: Drugs alone will not solve health problems. Without health education, a person may fall sick again and again from the same disease. Educating the people about the prevention and control of locally endemic diseases is the first of the eight essential activities in primary health care. 23. - Psychological health: Psychological health problem can occur everywhere. There is a tendency to an increase in the prevalence of psychological diseases when there is a change in society from agriculture to an industrial economy and when people move from the warm intimacy of a village. 24. - Prevention of accidents: Accidents are a feature of the complexity of modern life. Accidents can occur in home, road and place of work. The predominant factor in accidents is carelessness that can be tackled by health education. 25. - Use of health services: Many people, particularly in rural areas, do not know what health services are available and many more do not know. There is a communication gap between the public and state health administration in the form of feedback for further improvement of health services. One of the declared aims of health education is to inform people about the health services available in their community. 26. PLANNING FOR HEALTH EDUCATION planning: is the process of making thoughtful and systemic decision about what needs to be done , how it has to be done, by whom And with what sources. 27. Principles of planning health education 1) Focus on actual current needs and context of community: It is important that plans are made with the needs and context of the community in mind. Health education should try to understand what is currently happening in the community one works in. 2) Plan for basic needs and interest of the community: Consider the basic needs and interests of the community. If the local needs and interests are not kept under consideration, the plans may not be effective. 28. 3) Planning with actual beneficiaries of health education: Plan with the people involved in the implementation of an activity. If people are included in planning, they will be more likely to participate and the plan will be more likely to succeed. 4) Identify and use all relevant community resources: It is essential that the health educator identify all the relevant resources that are locally available which could be used for benefit of people receiving the health education. 29. 5) Follow principle of flexibility: Planning should be flexible, not rigid. One should be able to modify the plans when necessary. For example, you would have to change your priorities if a new problem needing an urgent response arose. 6) A realistic plan not hypothetical: The planned activity should be achievable and take into consideration the financial, personal resources available and time constraints. Planning must be realistic; do not plan unachievable activities. 30. Steps in planning health education Planning is a continuous process. It does not just happen at the start of project . Health education must be well planned to actually improve and promote individual, family and community health 31. - Needs assessment: Conducting needs assessment is the first and probably the most important step in any successful planning process. assessment is the process of identifying and understanding the health problems of the community and their possible causes. - Identify priorities: After identifying the needs and resources of the community, the next is to identify their priorities because each community may have several problems but the urgent have to be given top priority in health education. For example: goitre 32. - Set the goals and objectives: In planning the process of health education, setting goals and objectives is the third and most essential step because these goals and objectives serve as consciously thought baseline parameters to be achieved during health education. - Develop strategies: Prior to the implementation of the health education intervention one must plan, develop and evaluate the several alternative strategies to achieve the set goals and objectives of health education because each problem and target community is quite unique. 33. - Implementation: This is the core phase of the health education process which includes carrying out the planned strategies so that the set goals and objectives of health education may be achieved. - Monitor and evaluation: This is the final step of the planning process of health education where continuous monitoring as well as end evaluation is carried out to ensure the degree to which stated goals and objectives have been achieved. 34. LEVELS/APPROACH OF HEALTH EDUCATION 35. INDIVIDUAL LEVEL - Individual Approach: The health education must first create an atmosphere of friendship and allow the individual to talk as much as possible. In this individual teaching we can discuss, argue and persuade the individual to change his behaviour. But by this we can reach to a small population and who come in contact with us. Methods of individual health education 1) Home visit 2) Personal contact/ counselling 3) Personnel letters 36. 1) Home visit: A home visit is one of the best approaches for individual health education because it can become one of the best opportunities for health education with individuals and their families. Home visits are important to understand the real background of families, their living conditions and the environment in which they live. 37. 2) Personal contact/counseling : Personal contacts or counselling (one-to-one communication) is a helping process where one person explicitly and purposefully gives his or her time to assist people explore their situations and act on a solution. After this the counsellor needs to work together with the person to find solutions that are appropriate to their situation. 38. 3) personal letters: Personal letters may also be used for individual health education, where health educators may get an opportunity to dispatch letters or printed education material to the people in a target community. 39. GROUP LEVEL Group health education may be useful way to deliver health education massages in efficient manner. A well organized group permits sharing of experiences and skills so that people are able to learn from each other. 40. Methods of group discussion 1)Lecture method: (Chalk & Talk ) A lecture may be defined as carefully prepared oral presentation of facts organized thoughts and ideas by a qualified person. The group should not be more than 30 and talk should not exceed 15-20 minutes. By using suitable audiovisual aids. 2) Group discussion: A group is an aggregation of people interacting in a face to face situation. It is a very effective method of health communication. 41. 3) Demonstration: A demonstration is a carefully prepared presentation to show how to perform a skill. This procedure is carried out step by step before an audience. 4) Panel discussion: In a panel discussion 4-8 qualified persons talk about the topic. Sit and discuss a given topic in front of a large group/audience. The chairman opens the meeting. Panel comprises of a chair person and 4-8 speakers. After the main aspect of the subject are explored, the audience is invited to take part. 42. 5) Symposium: It is a series of speeches on a selected subject. Each expert person present it briefly and at the end of session the chair person make a comprehensive summary. Audience are allowed to raise question. 6) Workshops : It consists of series of meetings usually 4 or more with emphasis on an individual work, within the group and with the help of consultants and response personnel. 7) Role play: This is a brief acting out of an actual situation for the benefit of the audience for better understanding. 43. 8) Conference and seminars: This programmes are usually held on a regional, state/national level. Where several experts from different disciplines meet to deliberate on a particular theme, to appraise others of latest knowledge and research in a particular field. 9) Open forum: It refers to the public meeting which are held for various purposes in the community, for example: gram sabha 44. COMMUNITY LEVEL It is meant for a defined community and is not only to create awareness but also to help people understand their health problems and needs, find alternatives solutions to their problems and needs , implement them, evaluate and get feedback and accordingly do the needful. For health education at the community level, it is better to approach local leaders who are influential and who have the people’s confidence. These may include local officers such as gramsevak, panchayat sarpanch ,police officer or block development officer etc . 45. HOSPITAL LEVEL 1) Health Education in OPD/Outdoor: The patient and his attendants have to spend a lot of time in the outpatient department for health check-up, treatment, registration, diagnosis, admission procedure etc. This period can be utilised for health education. For this, the following means/devices can be used: - Exhibiting pictures, posters, charts, bulletin board and models in the waiting hall. - Arranging group discussion, slide show, or documentary film in a proper place and on a proper topic. - Giving health education on a personal level in the consulting room. This mainly includes nutrition clinic, family planning clinic, psychiatric clinic etc. 46. - Distributing pamphlets. - Arranging street plays or nukkad naatak in the outpatient department or its neighbourhood. 47. 2) Health Education in wards/ IPD: While taking care of the patients the indoor patients, doctors s have the opportunities to educate them. This period can be fully utilised to give health education to the patients. For this the following methods can be effective: - Conversation with the patient and motivating him for change in his behaviour. - Imparting health education by arranging live demonstration for nutrition, treatment, diagnosis etc. - Providing clinical or bedside teaching. - Providing incidental teaching to patient and his attendants. 48. - Presenting examples. To describe the gains of health education in an individual suffering from the same health education in an individual suffering from the same disease and arranging a meeting between the patient and the cured old patients.
Learners should know and understand the role of practitioners in supporting children (and their families/carers) living with a range of conditions and/or additional needs.
By the late 1800s, the Spanish were losing control of Cuba. Concerned about insurrection in the countryside, they moved rural Cubans to “reconcentration” camps where the Spanish claimed they would be better able to protect them. U.S. Consul-General Fitzhugh Lee forwarded the following account of the conditions of the camps to the U.S. Assistant Secretary of State on November 27, 1897. Lee said the author of the note was “a man of integrity and character.” “[W]e will relate to you what we saw with our own eyes: “Four hundred and sixty women and children thrown on the ground, heaped pellet-mell as animals, some in a dying condition, others sick and others dead. . . . “There is still alive the only living witness, a young girl of 18 years, whom we found seemingly lifeless on the ground; on her right-hand side was the body of a young mother, cold and rigid, but with her young child still alive clinging to her dead body; on her left-hand side was also the corpse of a dead woman holding her son in a dead embrace. . . . “The circumstances are the following: complete accumulation of bodies dead and alive, so that it was impossible to take one step without walking over them; the greatest want of cleanliness, want of light, air, and water; the food lacking in quality and quantity what was necessary to sustain life. . . . From all this we deduct that the number of deaths among the reconcentrados has amounted to 77 per cent.” Source: Unsigned note that was included in a telegram sent by Fitzhugh Lee, U.S. Consul-General in Cuba, to the U.S. Assistant Secretary of State November 27, 1897. consul-general: a government official living in a foreign country charged with overseeing the protection of U.S. citizens and promoting trade pell-mell: state of disorder accumulation: pile want: lack reconcentrados: the reconcentration camp prisoners; The following is an excerpt from Albert J. Beveridge’s speech, delivered September 16, 1898. Beveridge gave this speech while he was campaigning to become a senator for Indiana. The speech helped him win the election and made him one of the leading advocates of American expansion. “Fellow citizens, it is a noble land that God has given us; a land that can feed and clothe the world;. . . . It is a mighty people that he has planted on this soil . . . It is a glorious history our God has bestowed upon his chosen people; . . .a history of soldiers who carried the flag across the blazing deserts and through the ranks of hostile mountains, even to the gates of sunset. . . . “The Opposition tells us that we ought not to govern a people without their consent. I answer: The rule of liberty that all just government derives its authority from the consent of the governed, applies only to those who are capable of self-government. I answer, We govern the Indians without their consent, we govern our territories without their consent, we govern our children without their consent. “They ask us how we will govern these new possessions. I answer: If England can govern foreign lands, so can America. If Germany can govern foreign lands, so can America. . . . “What does all this mean for every one of us? It means opportunity for all the glorious young manhood of the republic, the most virile, ambitious, impatient, militant manhood the world has ever seen. It means that the resources and the commerce of these immensely rich dominions will be increased. . . . “In Cuba, alone, there are 15,000,000 acres of forest unacquainted with the axe. There are exhaustless mines of iron. . . . There are millions of acres yet unexplored. . . . It means new employment and better wages for every laboring man in the Union. . . .