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4.5.2 Systems of Equations:Graphs
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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 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 cellsMake a test, with answers best on the following: Conduct an investigation to provide evidence that living things are made of cells; either one cell or many different numbers and types of cells. Supporting Content LS1.A: Structure and Function • All living things are made up of cells, which is the smallest unit that can be said to be alive. An organism may consist of one single cell (unicellular) or many different numbers and types of cells (multicellular). (MS-LS-1.1) Further Explanation: Emphasis is on developing evidence that living things are made of cells, distinguishing between living and non-living things, and understanding that living things may be made of one cell or many and varied cells. In multicellular organisms, the body is a system of multiple interacting subsystems. These subsystems are groups of cells that work together to form tissues and organs that are specialized for particular body functions. (MS-LS-1.3) Further Explanation: Emphasis is on the conceptual understanding that cells form tissues and tissues form organs specialized for particular body functions. Examples could include the interaction of subsystems within a system and the normal functioning of those systems. Organisms reproduce, either sexually or asexually, and transfer their genetic information to their offspring. (MS-LS-1.4) • Living things share certain characteristics. (These include response to environment, reproduction, energy use, growth and development, life cycles, made of cells, etc.) (MS-LS1.4) Further Explanation: Examples should include both biotic and abiotic items, and should be defended using accepted characteristics of life. Plants, algae (including phytoplankton), and many microorganisms use the energy from light to make sugars (food) from carbon dioxide from the atmosphere and water through the process of photosynthesis, which also releases oxygen. These sugars can be used immediately or stored for growth or later use. (MS-LS-1.5) Further Explanation: Emphasis is on tracing movement of matter and flow of energy. Supporting Content LS1.C: Organization for Matter and Energy Flow in Organisms • Within individual organisms, food moves through a series of chemical reactions (cellular respiration) in which it is broken down and rearranged to form new molecules, to support growth, or to release energy. (MS-LS-1.6) Further Explanation: Emphasis is on describing that molecules are broken apart and put back together and that in this process, energy is released and on understanding that the elements in the products are the same as the elements in the reactants. Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors. (MS-LS-2.1) • In any ecosystem, organisms and populations with similar requirements for food, water, oxygen, or other resources may compete with each other for limited resources, access to which consequently constrains their growth and reproduction. (MS-LS-2.1) • Growth of organisms and population increases are limited by access to resources. (MS-LS-2.1) Further Explanation: Emphasis is on cause and effect relationships between resources and growth of individual organisms and the numbers of organisms in ecosystems during periods of abundant and scarce resources. Similarly, predatory interactions may reduce the number of organisms or eliminate whole populations of organisms. Mutually beneficial interactions, in contrast, may become so interdependent that each organism requires the other for survival. Although the species involved in these competitive, predatory, and mutually beneficial interactions vary across ecosystems, the patterns of interactions of organisms with their environments, both living and nonliving, are shared. (MS-LS-2.2) Further Explanation: Emphasis is on predicting consistent patterns of interactions in different ecosystems in terms of the relationships among and between organisms and abiotic components of ecosystems. Examples of types of interactions could include competitive, predatory, and mutually beneficial. Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem. Transfers of matter into and out of the physical environment occur at every level. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem. (MS-LS-2.3) Further Explanation: Emphasis is on describing the conservation of matter and flow of energy into and out of various ecosystems, and on defining the boundaries of the system. Ecosystems are dynamic in nature; their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations. (MSLS-2.5) Further Explanation: Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems. Biodiversity describes the variety of species found in Earth’s terrestrial and oceanic ecosystems. The completeness or integrity of an ecosystem’s biodiversity is often used as a measure of its health. (MS-LS-2.6) Supporting Content LS4.D: Biodiversity • Changes in biodiversity can influence humans’ resources, such as food, energy, and medicines, as well as ecosystem services that humans rely on—for example, water purification and recycling. (MS-LS-2.6) Supporting Content ETS1.B: Developing Possible Solutions • There are systematic processes for evaluating solutions with respect to how well they meet the criteria and constraints of a problem. (MS-LS-2.6) Further Explanation: Examples of ecosystem services could include water purification, nutrient recycling, and prevention of soil erosion. Examples of design solution constraints could include scientific, economic, and social considerations. Genes are located in the chromosomes of cells, with each chromosome pair containing two variants of each of many distinct genes. Each distinct gene chiefly controls the production of specific proteins, which in turn affects the traits of the individual. Structural changes to genes (mutations) can result in changes to proteins, which can affect the structures and functions of the organism and thereby change traits. (MS-LS-3.1) Supporting Content LS3.B: Variation of Traits • In addition to variations that arise from sexual reproduction, genetic information can be altered because of mutations. Though rare, mutations may result in significant changes to the structure and function of proteins. Changes can be beneficial, harmful, or neutral to the organism. (MS-LS-3.1) Further Explanation: Emphasis is on conceptual understanding that changes in genetic material may result in making different proteins. Organisms reproduce, either sexually or asexually, and transfer their genetic information to their offspring. (MS-LS-3.2) Supporting Content LS3.A: Inheritance of Traits • Variations of inherited traits between parent and offspring arise from genetic differences that result from the subset of chromosomes (and therefore genes) inherited. (MS-LS-3.2) Supporting Content LS3.B: Variation of Traits • In sexually reproducing organisms, each parent contributes half of the genes acquired (at random) by the offspring. Individuals have two of each chromosome and hence two alleles of each gene, one acquired from each parent. These versions may be identical or may differ from each other. (MS-LS-3.2) Further Explanation: Emphasis is on using models such as simple Punnett squares and pedigrees, diagrams, and simulations to describe the cause and effect relationship of gene transmission from parent(s) to offspring and resulting genetic variation. The collection of fossils and their placement in chronological order is known as the fossil record and documents the change of many life forms throughout the history of the Earth. Anatomical similarities and differences between various organisms living today and between living and once living organisms in the fossil record enable the classification of living things. (MS-LS-4.1, MS-LS-4.2) Further Explanation: Emphasis is on finding patterns of changes in the level of complexity of anatomical structures in organisms and the chronological order of fossil appearance in the rock layers. The collection of fossils and their placement in chronological order is known as the fossil record and documents the change of many life forms throughout the history of the Earth. Anatomical similarities and differences between various organisms living today and between living and once living organisms in the fossil record enable the classification of living things. (MS-LS-4.1, MS-LS-4.2) Further Explanation: Emphasis is on explanations of the relationships among organisms in terms of similarity or differences of the gross appearance of anatomical structures. Scientific genus and species level names indicate a degree of relationship. (MS-LS-4.3) Further Explanation: Emphasis is on inferring general patterns of relatedness among structures of different organisms by comparing diagrams, pictures, specimens, or fossils. Natural selection leads to the predominance of certain traits in a population, and the suppression of others. (MS-LS-4.4) Further Explanation: Emphasis is on using concepts of natural selection, including overproduction of offspring, passage of time, variation in a population, selection of favorable traits, and heritability of traits. In artificial selection, humans have the capacity to influence certain characteristics of organisms by selective breeding. One can choose desired parental traits determined by genes, which are then passed to offspring. (MS-LS-4.5) Further Explanation: Emphasis is on identifying and communicating information from reliable sources about the influence of humans on genetic outcomes in artificial selection (such as genetic modification, animal husbandry, gene therapy), and on the influence these technologies have on society as well as the technologies leading to these scientific discoveries. Adaptation by natural selection acting over generations is one important process by which species change over time in response to changes in environmental conditions. Traits that support successful survival and reproduction in the new environment become more common; those that do not become less common. Thus, the distribution of traits in a population changes. (MS-LS-4.6) Further Explanation: Emphasis is on using mathematical models, probability statements, and proportional reasoning to support explanations of trends in changes to populations over time. Examples could include Peppered Moth population changes before and after the industrial revolution. Cells of different organisms and even cells within the same organism are very diverse in terms of shape, size, and internal organization. One theme that occurs again and again throughout biology is that form follows function. In other words, a cell’s function influences its physical features. Cell Shape The diversity in cell shapes reflects the different functions of cells. Compare the cell shapes shown in Figure 4-4. The long extensions that reach out in various directions from the nerve cell shown in Figure 4-4a allow the cell to send and receive nerve impulses. The flat, platelike shape of skin cells in Figure 4-4b suits their function of covering and protecting the surface of the body. As shown below, a cell’s shape can be simple or complex depending on the function of the cell. Each cell has a shape that has evolved to allow the cell to perform its function effectively. SECTION 2 OBJECTIVES ● Explain the relationship between cell shape and cell function. ● Identify the factor that limits cell size. ● Describe the three basic parts of a cell. ● Compare prokaryotic cells and eukaryotic cells. ● Analyze the relationship among cells, tissues, organs, organ systems, and organisms. VOCABULARY plasma membrane cytoplasm cytosol nucleus prokaryote eukaryote organelle tissue organ organ system Cells have various shapes. (a) Nerve cells have long extensions. (b) Skin cells are flat and platelike. (c) Egg cells are spherical. (d) Some bacteria are rod shaped. (e) Some plant cells are rectangular. FIGURE 4-4 (a) Nerve cell (b) Skin cells (c) Egg cell (d) Bacterial cells (e) Plant cells Copyright © by Holt, Rinehart and Winston. All rights reserved. 1. All cubes have volume and surface area. The total surface area is equal to the sum of the areas of each of the six sides (area = length X width). 2. If you split the first cube into eight smaller cubes, you get 48 sides. The volume remains constant, but the total surface area doubles. 3. If you split each of the eight cubes into eight smaller cubes, you have 64 cubes that together contain the same volume as the first cube. The total surface area, however, has doubled again. CELL STRUCTURE AND FUNCTION 73 Cell Size Cells differ not only in their shape but also in their size. A few types of cells are large enough to be seen by the unaided human eye. For example, the nerve cells that extend from a giraffe’s spinal cord to its foot can be 2 m (about 6 1/2 ft) long. A human egg cell is about the size of the period at the end of this sentence. Most cells, how- ever, are only 10 to 50 μm in diameter, or about 1/500 the size of the period at the end of this sentence. The size of a cell is limited by the relationship of the cell’s outer surface area to its volume, or its surface area–to-volume ratio. As a cell grows, its volume increases much faster than its surface area does, as shown in Figure 4-5. This trend is important because the materials needed by a cell (such as nutrients and oxygen) and the wastes produced by a cell (such as carbon dioxide) must pass into and out of the cell through its surface. If a cell were to become very large, the volume would increase much more than the surface area. Therefore, the surface area would not allow materials to enter or leave the cell quickly enough to meet the cell’s needs. As a result, most cells are microscopic in size. Comparing Surface Cells Materials microscope, prepared slides of plant (dicot) stem and ani- mal (human) skin, pencil, paper Procedure Examine slides by using medium magnification (100). Observe and draw the sur- face cells of the plant stem and the animal skin. Analysis How do the surface cells of each organism differ from the cells beneath the surface cells? What is the function of the surface cells? Explain how surface cells are suited to their function based on their shape. Quick Lab Small cells can exchange substances more readily than large cells because small objects have a higher surface area–to-volume ratio. FIGURE 4-5 mb06se_csfs02.qxd 5/18/07 10:54 AM Page 73 74 CHAPTER 4 BASIC PARTS OF A CELL Despite the diversity among cells, three basic features are common to all cell types. All cells have an outer boundary, an interior sub- stance, and a control region. Plasma Membrane The cell’s outer boundary, called the plasma membrane (or the cell membrane), covers a cell’s surface and acts as a barrier between the inside and the outside of a cell. All materials enter or exit through the plasma membrane. The surface of a plasma mem- brane is shown in Figure 4-6a. Cytoplasm The region of the cell that is within the plasma membrane and that includes the fluid, the cytoskeleton, and all of the organelles except the nucleus is called the cytoplasm. The part of the cytoplasm that includes molecules and small particles, such as ribosomes, but not membrane-bound organelles is the cytosol. About 20 percent of the cytosol is made up of protein. Control Center Cells carry coded information in the form of DNA for regulating their functions and reproducing themselves. The DNA in some types of cells floats freely inside the cell. Other cells have a mem- brane-bound organelle that contains a cell’s DNA. This membrane- bound structure is called the nucleus. Most of the functions of a eukaryotic cell are controlled by the cell’s nucleus. The nucleus is often the most prominent structure within a eukaryotic cell. It maintains its shape with the help of a protein skeleton called the nuclear matrix. The nucleus of a typical animal cell is shown inEnzyme Classifications Traditionally, enzymes were simply assigned names by the investigator who discovered the enzyme. As knowledge expanded, systems of enzyme classification became more comprehensive and complex. Currently enzymes are grouped into six functional classes by the International Union of Biochemists (I.U.B.). Number Classification Biochemical Properties 1 Oxidoreductases Act on many chemical groupings to add or remove hydrogen atoms. 2 Transferases Transfer functional groups between donor and acceptor molecules. Kinases are specialized transferases that regulate metabolism by transferring phosphate from ATP to other molecules. 3 Hydrolases Add water across a bond, hydrolyzing it. 4 Lyases Add water, ammonia or carbon dioxide across double bonds, or remove these elements to produce double bonds. 5 Isomerases Carry out many kinds of isomerization: L to D isomerizations, mutase reactions (shifts of chemical groups) and others. 6 Ligases Catalyze reactions in which two chemical groups are joined (or ligated) with the use of energy from ATP.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 agency’s 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 DepEd’s 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 Department’s mandate, vision, mission and strategic goals. It shall ensure 100% results orientation vis-a-vis the planned targets. On the other hand, the ratee’s 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 one’s results. Competencies shall uphold the DepEd’s 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 ratee’s 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 employee’s 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 – 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 individual’s 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) – all competency indicators 4 (consistently demonstrates) – four competency indicators 3 (most of the time demonstrates) – three competency indicators 2 (sometimes demonstrates) – two competency indicators 1 (rarely demonstrates) – 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 employee’s 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 individual’s 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 ratee’s 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 ratee’s development needs. Make a situational SOLO-based questions in the context of school leadershipILLINOIS PROFESSIONAL TEACHING STANDARDS (2013) Standard 1 - Teaching Diverse Students – The competent teacher understands the diverse characteristics and abilities of each student and how individuals develop and learn within the context of their social, economic, cultural, linguistic, and academic experiences. The teacher uses these experiences to create instructional opportunities that maximize student learning. Knowledge Indicators – The competent teacher: 1A) understands the spectrum of student diversity (e.g., race and ethnicity, socioeconomic status, special education, gifted, English language learners (ELL), sexual orientation, gender, gender identity) and the assets that each student brings to learning across the curriculum; 1B) understands how each student constructs knowledge, acquires skills, and develops effective and efficient critical thinking and problem-solving capabilities; 1C) understands how teaching and student learning are influenced by development (physical, social and emotional, cognitive, linguistic), past experiences, talents, prior knowledge, economic circumstances and diversity within the community; 1D) understands the impact of cognitive, emotional, physical, and sensory disabilities on learning and communication pursuant to the Individuals with Disabilities Education Improvement Act (also referred to as “IDEA”) (20 USC 1400 et seq.), its implementing regulations (34 CFR 300; 2006), Article 14 of the School Code [105 ILCS 5/Art.14] and 23 Ill. Adm. Code 226 (Special Education); 1E) understands the impact of linguistic and cultural diversity on learning and communication; 1F) understands his or her personal perspectives and biases and their effects on one’s teaching; and 1G) understands how to identify individual needs and how to locate and access technology, services, and resources to address those needs. Performance Indicators – The competent teacher: 1H) analyzes and uses student information to design instruction that meets the diverse needs of students and leads to ongoing growth and achievement; 1I) stimulates prior knowledge and links new ideas to already familiar ideas and experiences; 1J) differentiates strategies, materials, pace, levels of complexity, and language to introduce concepts and principles so that they are meaningful to students at varying levels of development and to students with diverse learning needs; 1K) facilitates a learning community in which individual differences are respected; and 1L) uses information about students’ individual experiences, families, cultures, and communities to create meaningful learning opportunities and enrich instruction for all students. Standard 2 - Content Area and Pedagogical Knowledge – The competent teacher has in-depth understanding of content area knowledge that includes central concepts, methods of inquiry, structures of the disciplines, and content area literacy. The teacher creates meaningful learning experiences for each student based upon interactions among content area and pedagogical knowledge, and evidence-based practice. Knowledge Indicators – The competent teacher: 2A) understands theories and philosophies of learning and human development as they relate to the range of students in the classroom; 2B) understands major concepts, assumptions, debates, and principles; processes of inquiry; and theories that are central to the disciplines; 2C) understands the cognitive processes associated with various kinds of learning (e.g., critical and creative thinking, problem-structuring and problem-solving, invention, memorization, and recall) 2 and ensures attention to these learning processes so that students can master content standards; 2D) understands the relationship of knowledge within the disciplines to other content areas and to life applications; 2E) understands how diverse student characteristics and abilities affect processes of inquiry and influence patterns of learning; 2F) knows how to access the tools and knowledge related to latest findings (e.g., research, practice, methodologies) and technologies in the disciplines; 2G) understands the theory behind and the process for providing support to promote learning when concepts and skills are first being introduced; and 2H) understands the relationship among language acquisition (first and second), literacy development, and acquisition of academic content and skills. Performance Indicators – The competent teacher: 2I) evaluates teaching resources and materials for appropriateness as related to curricular content and each student’s needs; 2J) uses differing viewpoints, theories, and methods of inquiry in teaching subject matter concepts; 2K) engages students in the processes of critical thinking and inquiry and addresses standards of evidence of the disciplines; 2L) demonstrates fluency in technology systems, uses technology to support instruction and enhance student learning, and designs learning experiences to develop student skills in the application of technology appropriate to the disciplines; 2M) uses a variety of explanations and multiple representations of concepts that capture key ideas to help each student develop conceptual understanding and address common misunderstandings; 2N) facilitates learning experiences that make connections to other content areas and to life experiences; 2O) designs learning experiences and utilizes assistive technology and digital tools to provide access to general curricular content to individuals with disabilities; 2P) adjusts practice to meet the needs of each student in the content areas; and 2Q) applies and adapts an array of content area literacy strategies to make all subject matter accessible to each student. Standard 3 - Planning for Differentiated Instruction – The competent teacher plans and designs instruction based on content area knowledge, diverse student characteristics, student performance data, curriculum goals, and the community context. The teacher plans for ongoing student growth and achievement. Knowledge Indicators – The competent teacher: 3A) understands the Illinois Learning Standards (23 Ill. Adm. Code 1.Appendix D), curriculum development process, content, learning theory, assessment, and student development and knows how to incorporate this knowledge in planning differentiated instruction; 3B) understands how to develop short- and long-range plans, including transition plans, consistent with curriculum goals, student diversity, and learning theory; 3C) understands cultural, linguistic, cognitive, physical, and social and emotional differences, and considers the needs of each student when planning instruction; 3D) understands when and how to adjust plans based on outcome data, as well as student needs, goals, and responses; 3E) understands the appropriate role of technology, including assistive technology, to address student needs, as well as how to incorporate contemporary tools and resources to maximize student learning; 3 3F) understands how to co-plan with other classroom teachers, parents or guardians, paraprofessionals, school specialists, and community representatives to design learning experiences; and 3G) understands how research and data guide instructional planning, delivery, and adaptation. Performance Indicators – The competent teacher: 3H) establishes high expectations for each student’s learning and behavior; 3I) creates short-term and long-term plans to achieve the expectations for student learning; 3J) uses data to plan for differentiated instruction to allow for variations in individual learning needs; 3K) incorporates experiences into instructional practices that relate to a student’s current life experiences and to future life experiences; 3L) creates approaches to learning that are interdisciplinary and that integrate multiple content areas; 3M) develops plans based on student responses and provides for different pathways based on student needs; 3N) accesses and uses a wide range of information and instructional technologies to enhance a student’s ongoing growth and achievement; 3O) when planning instruction, addresses goals and objectives contained in plans developed under Section 504 of the Rehabilitation Act of 1973 (29 USC 794), individualized education programs (IEP) (see 23 Ill. Adm. Code 226 (Special Education)) or individual family service plans (IFSP) (see 23 Ill. Adm. Code 226 and 34 CFR 300.24; 2006); 3P) works with others to adapt and modify instruction to meet individual student needs; and 3Q) develops or selects relevant instructional content, materials, resources, and strategies (e.g., project-based learning) for differentiating instruction. Standard 4 - Learning Environment – The competent teacher structures a safe and healthy learning environment that facilitates cultural and linguistic responsiveness, emotional well-being, self-efficacy, positive social interaction, mutual respect, active engagement, academic risk-taking, self-motivation, and personal goal-setting. Knowledge Indicators – The competent teacher: 4A) understands principles of and strategies for effective classroom and behavior management; 4B) understands how individuals influence groups and how groups function in society; 4C) understands how to help students work cooperatively and productively in groups; 4D) understands factors (e.g., self-efficacy, positive social interaction) that influence motivation and engagement; 4E) knows how to assess the instructional environment to determine how best to meet a student’s individual needs; 4F) understands laws, rules, and ethical considerations regarding behavior intervention planning and behavior management (e.g., bullying, crisis intervention, physical restraint); 4G) knows strategies to implement behavior management and behavior intervention planning to ensure a safe and productive learning environment; and 4H) understands the use of student data (formative and summative) to design and implement behavior management strategies. Performance Indicators – The competent teacher: 4I) creates a safe and healthy environment that maximizes student learning; 4J) creates clear expectations and procedures for communication and behavior and a physical setting conducive to achieving classroom goals; 4K) uses strategies to create a smoothly functioning learning community in which students assume responsibility for themselves and one another, participate in decision-making, work collaboratively and independently, use appropriate technology, and engage in purposeful learning activities; 4 4L) analyzes the classroom environment and makes decisions to enhance cultural and linguistic responsiveness, mutual respect, positive social relationships, student motivation, and classroom engagement; 4M) organizes, allocates, and manages time, materials, technology, and physical space to provide active and equitable engagement of students in productive learning activities; 4N) engages students in and monitors individual and group-learning activities that help them develop the motivation to learn; 4O) uses a variety of effective behavioral management techniques appropriate to the needs of all students that include positive behavior interventions and supports; 4P) modifies the learning environment (including the schedule and physical arrangement) to facilitate appropriate behaviors and learning for students with diverse learning characteristics; and 4Q) analyzes student behavior data to develop and support positive behavior. Standard 5 - Instructional Delivery – The competent teacher differentiates instruction by using a variety of strategies that support critical and creative thinking, problem-solving, and continuous growth and learning. This teacher understands that the classroom is a dynamic environment requiring ongoing modification of instruction to enhance learning for each student. Knowledge Indicators – The competent teacher: 5A) understands the cognitive processes associated with various kinds of learning; 5B) understands principles and techniques, along with advantages and limitations, associated with a wide range of evidence-based instructional practices; 5C) knows how to implement effective differentiated instruction through the use of a wide variety of materials, technologies, and resources; 5D) understands disciplinary and interdisciplinary instructional approaches and how they relate to life and career experiences; 5E) knows techniques for modifying instructional methods, materials, and the environment to facilitate learning for students with diverse learning characteristics; 5F) knows strategies to maximize student attentiveness and engagement; 5G) knows how to evaluate and use student performance data to adjust instruction while teaching; and 5H) understands when and how to adapt or modify instruction based on outcome data, as well as student needs, goals, and responses. Performance Indicators – The competent teacher: 5I) uses multiple teaching strategies, including adjusted pacing and flexible grouping, to engage students in active learning opportunities that promote the development of critical and creative thinking, problem-solving, and performance capabilities; 5J) monitors and adjusts strategies in response to feedback from the student; 5K) varies his or her role in the instructional process as instructor, facilitator, coach, or audience in relation to the content and purposes of instruction and the needs of students; 5L) develops a variety of clear, accurate presentations and representations of concepts, using alternative explanations to assist students’ understanding and presenting diverse perspectives to encourage critical and creative thinking; 5M) uses strategies and techniques for facilitating meaningful inclusion of individuals with a range of abilities and experiences; 5N) uses technology to accomplish differentiated instructional objectives that enhance learning for each student; 5O) models and facilitates effective use of current and emerging digital tools to locate, analyze, evaluate, and use information resources to support research and learning; 5P) uses student data to adapt the curriculum and implement instructional strategies and materials according to the characteristics of each student; 5 5Q) uses effective co-planning and co-teaching techniques to deliver instruction to all students; 5R) maximizes instructional time (e.g., minimizes transitional time); and 5S) implements appropriate evidence-based instructional strategies. Standard 6 - Reading, Writing, and Oral Communication – The competent teacher has foundational knowledge of reading, writing, and oral communication within the content area and recognizes and addresses student reading, writing, and oral communication needs to facilitate the acquisition of content knowledge. Knowledge Indicators – The competent teacher: 6A) understands appropriate and varied instructional approaches used before, during, and after reading, including those that develop word knowledge, vocabulary, comprehension, fluency, and strategy use in the content areas; 6B) understands that the reading process involves the construction of meaning through the interactions of the reader's background knowledge and experiences, the information in the text, and the purpose of the reading situation; 6C) understands communication theory, language development, and the role of language in learning; 6D) understands writing processes and their importance to content learning; 6E) knows and models standard conventions of written and oral communications; 6F) recognizes the relationships among reading, writing, and oral communication and understands how to integrate these components to increase content learning; 6G) understands how to design, select, modify, and evaluate a wide range of materials for the content areas and the reading needs of the student; 6H) understands how to use a variety of formal and informal assessments to recognize and address the reading, writing, and oral communication needs of each student; and 6I) knows appropriate and varied instructional approaches, including those that develop word knowledge, vocabulary, comprehension, fluency, and strategy use in the content areas. Performance Indicators – The competent teacher: 6J) selects, modifies, and uses a wide range of printed, visual, or auditory materials, and online resources appropriate to the content areas and the reading needs and levels of each student (including ELLs, and struggling and advanced readers); 6K) uses assessment data, student work samples, and observations from continuous monitoring of student progress to plan and evaluate effective content area reading, writing, and oral communication instruction; 6L) facilitates the use of appropriate word identification and vocabulary strategies to develop each student’s understanding of content; 6M) teaches fluency strategies to facilitate comprehension of content; 6N) uses modeling, explanation, practice, and feedback to teach students to monitor and apply comprehension strategies independently, appropriate to the content learning; 6O) teaches students to analyze, evaluate, synthesize, and summarize information in single texts and across multiple texts, including electronic resources; 6P) teaches students to develop written text appropriate to the content areas that utilizes organization (e.g., compare/contrast, problem/solution), focus, elaboration, word choice, and standard conventions (e.g., punctuation, grammar); 6Q) integrates reading, writing, and oral communication to engage students in content learning; 6R) works with other teachers and support personnel to design, adjust, and modify instruction to meet students’ reading, writing, and oral communication needs; and 6S) stimulates discussion in the content areas for varied instructional and conversational purposes. Standard 7 - Assessment – The competent teacher understands and uses appropriate formative and summative assessments for determining student needs, monitoring student progress, measuring student 6 growth, and evaluating student outcomes. The teacher makes decisions driven by data about curricular and instructional effectiveness and adjusts practices to meet the needs of each student. Knowledge Indicators – The competent teacher: 7A) understands the purposes, characteristics, and limitations of different types of assessments, including standardized assessments, universal screening, curriculum-based assessment, and progress monitoring tools; 7B) understands that assessment is a means of evaluating how students learn and what they know and are able to do in order to meet the Illinois Learning Standards; 7C) understands measurement theory and assessment-related issues, such as validity, reliability, bias, and appropriate and accurate scoring; 7D) understands current terminology and procedures necessary for the appropriate analysis and interpretation of assessment data; 7E) understands how to select, construct, and use assessment strategies and instruments for diagnosis and evaluation of learning and instruction; 7F) knows research-based assessment strategies appropriate for each student; 7G) understands how to make data-driven decisions using assessment results to adjust practices to meet the needs of each student; 7H) knows legal provisions, rules, and guidelines regarding assessment and assessment accommodations for all student populations; and 7I) knows assessment and progress monitoring techniques to assess the effectiveness of instruction for each student. Performance Indicators – The competent teacher: 7J) uses assessment results to determine student performance levels, identify learning targets, select appropriate research-based instructional strategies, and implement instruction to enhance learning outcomes; 7K) appropriately uses a variety of formal and informal assessments to evaluate the understanding, progress, and performance of an individual student and the class as a whole; 7L) involves students in self-assessment activities to help them become aware of their strengths and needs and encourages them to establish goals for learning; 7M) maintains useful and accurate records of student work and performance; 7N) accurately interprets and clearly communicates aggregate student performance data to students, parents or guardians, colleagues, and the community in a manner that complies with the requirements of the Illinois School Student Records Act [105 ILCS 10], 23 Ill. Adm. Code 375 (Student Records), the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g) and its implementing regulations (34 CFR 99; December 9, 2008); 7O) effectively uses appropriate technologies to conduct assessments, monitor performance, and assess student progress; 7P) collaborates with families and other professionals involved in the assessment of each student; 7Q) uses various types of assessment procedures appropriately, including making accommodations for individual students in specific contexts; and 7R) uses assessment strategies and devices that are nondiscriminatory, and take into consideration the impact of disabilities, methods of communication, cultural background, and primary language on measuring knowledge and performance of students. Standard 8 - Collaborative Relationships – The competent teacher builds and maintains collaborative relationships to foster cognitive, linguistic, physical, and social and emotional development. This teacher works as a team member with professional colleagues, students, parents or guardians, and community members. Knowledge Indicators – The competent teacher: 8A) understands schools as organizations within the larger community context; 7 8B) understands the collaborative process and the skills necessary to initiate and carry out that process; 8C) collaborates with others in the use of data to design and implement effective school interventions that benefit all students; 8D) understands the benefits, barriers, and techniques involved in parent and family collaborations; 8E) understands school- and work-based learning environments and the need for collaboration with all organizations (e.g., businesses, community agencies, nonprofit organizations) to enhance student learning; 8F) understands the importance of participating on collaborative and problem-solving teams to create effective academic and behavioral interventions for all students; 8G) understands the various models of co-teaching and the procedures for implementing them across the curriculum; 8H) understands concerns of families of students with disabilities and knows appropriate strategies to collaborate with students and their families in addressing these concerns; and 8I) understands the roles and the importance of including students with disabilities, as appropriate, and all team members in planning individualized education programs (i.e, IEP, IFSP, Section 504 plan) for students with disabilities. Performance Indicators – The competent teacher: 8J) works with all school personnel (e.g., support staff, teachers, paraprofessionals) to develop learning climates for the school that encourage unity, support a sense of shared purpose, show trust in one another, and value individuals; 8K) participates in collaborative decision-making and problem-solving with colleagues and other professionals to achieve success for all students; 8L) initiates collaboration with others to create opportunities that enhance student learning; 8M) uses digital tools and resources to promote collaborative interactions; 8N) uses effective co-planning and co-teaching techniques to deliver instruction to each student; 8O) collaborates with school personnel in the implementation of appropriate assessment and instruction for designated students; 8P) develops professional relationships with parents and guardians that result in fair and equitable treatment of each student to support growth and learning; 8Q) establishes respectful and productive relationships with parents or guardians and seeks to develop cooperative partnerships to promote student learning and well-being; 8R) uses conflict resolution skills to enhance the effectiveness of collaboration and teamwork; 8S) participates in the design and implementation of individualized instruction for students with special needs (i.e., IEPs, IFSP, transition plans, Section 504 plans), ELLs, and students who are gifted; and 8T) identifies and utilizes community resources to enhance student learning and to provide opportunities for students to explore career opportunities. Standard 9 - Professionalism, Leadership, and Advocacy – The competent teacher is an ethical and reflective practitioner who exhibits professionalism; provides leadership in the learning community; and advocates for students, parents or guardians, and the profession. Knowledge Indicators – The competent teacher: 9A) evaluates best practices and research-based materials against benchmarks within the disciplines; 9B) knows laws and rules (e.g., mandatory reporting, sexual misconduct, corporal punishment) as a foundation for the fair and just treatment of all students and their families in the classroom and school; 9C) understands emergency response procedures as required under the School Safety Drill Act [105 ILCS 128/1], including school safety and crisis intervention protocol, initial response 8 actions (e.g., whether to stay in or evacuate a building), and first response to medical emergencies (e.g., first aid and life-saving techniques); 9D) identifies paths for continuous professional growth and improvement, including the design of a professional growth plan; 9E) is cognizant of his or her emerging and developed leadership skills and the applicability of those skills within a variety of learning communities; 9F) understands the roles of an advocate, the process of advocacy, and its place in combating or promoting certain school district practices affecting students; 9G) understands local and global societal issues and responsibilities in an evolving digital culture; and 9H) understands the importance of modeling appropriate dispositions in the classroom. Performance Indicators – The competent teacher: 9I) models professional behavior that reflects honesty, integrity, personal responsibility, confidentiality, altruism and respect; 9J) maintains accurate records, manages data effectively, and protects the confidentiality of information pertaining to each student and family; 9K) reflects on professional practice and resulting outcomes; engages in self-assessment; and adjusts practices to improve student performance, school goals, and professional growth; 9L) communicates with families, responds to concerns, and contributes to enhanced family participation in student education; 9M) communicates relevant information and ideas effectively to students, parents or guardians, and peers, using a variety of technology and digital-age media and formats; 9N) collaborates with other teachers, students, parents or guardians, specialists, administrators, and community partners to enhance students’ learning and school improvement; 9O) participates in professional development, professional organizations, and learning communities, and engages in peer coaching and mentoring activities to enhance personal growth and development; 9P) uses leadership skills that contribute to individual and collegial growth and development, school improvement, and the advancement of knowledge in the teaching profession; 9Q) proactively serves all students and their families with equity and honor and advocates on their behalf, ensuring the learning and well-being of each child in the classroom; 9R) is aware of and complies with the mandatory reporter provisions of Section 4 of the Abused and Neglected Child Reporting Act [325 ILCS 5/4]; 9S) models digital etiquette and responsible social actions in the use of digital technology; and 9T) models and teaches safe, legal, and ethical use of digital information and technology, including respect for copyright, intellectual property, and the appropriate documentation of sources.1.Linguistics is the science that studies language. 2.Linguist:Someone who studies linguistics. 3.The Subfields of Linguistics Phonetics deals with the sounds of language. Phonology deals with how the sounds are organized. Morphology deals with how sounds are put together to form words. Syntax deals with how sentences are formed. Semantics deals with the meaning of words, sentences, and texts. Pragmatics deals with how sentences and texts are used in the world (i.e., in context) Text Linguistics deals with units larger than sentences, such as paragraphs and texts. 4.Prescriptive: This approach consists basically of stating what is considered right and wrong in language. 5.Descriptive: This approach, on the other hand, consists of describing the facts. Descriptive linguistics is dedicated to describing the rules of the language, and the language is seen as essentially rule governed. 6.Language is rule-governed, creative, universal, innate, and learned, all at the same time. 7.Linguists understand language as a system of arbitrary vocal signs. 8.Linguistic signs: involve sequences of sounds which represent concrete objects and events as well as abstractions.Signs may be related to the things they represent in a number of ways. 9.Iconic: which resemble the things they represent (as do, for example, photographs, diagrams, star charts, or chemical models). 10.Indexical: which point to or have a necessary connection with the things they represent (as do, for example, smoke to fire, a weathercock to the direction of the wind, a symptom to an illness, a smile to happiness, or a frown to anger). 11.Describe the characteristics of human language: Creative: (The structural elements of human language can be combined to produce new utterances, which neither the speaker nor his hearers may ever have made or heard before.) Rule-governed: (Language is made of rules.) Universal: (There are some aspects that are present in all languages of the world.) Innate:(all humans possess an innate capacity for language, activated in infancy by minimal environmental stimuli. Chomsky) Uniquely human: (Language is what sets us apart from other species. It is what makes us human.) Learned:(Children acquire language from their natural setting.) 12.Differentiate between iconic, indexical and symbolic signs. A. iconic, which resemble the things they represent (as do, for example, photographs, diagrams, star charts, or chemical models) B. indexical, which point to or have a necessary connection with the things they represent (as do, for example, smoke to fire, a weathercock to the direction of the wind, a symptom to an illness, a smile to happiness, or a frown to anger). c. symbolic, which are only conventionally related to the thing they represent (as do, for example, a flag to a nation, a rose to love, a wedding ring to marriage). 12. Distinguish between different senses of the grammar word. The prescriptivist´s grammar (Grammar is a set of rules that label the different utterances as either right or wrong.) The descriptivist´s grammar (Grammar is a set of rules that govern the langauge spoken by people. ) The linguist´s grammar (Grammar is the subconscious knowledge of the set of rules that enables speakers to use the language) The speaker´s grammar (Grammar is the intrinsic linguistic knowledge within a native speaker) 13.Describe common fallacies about language and grammar: ►One type of grammar is simpler than another. ►Changes in grammar involve deterioration in a language ►Grammars should be logical and analogical (that is, regular) ►People must be taught the grammatical rules of their language. ►Only some languages have grammar. ►Grammars differ from each other in unpredictable ways. 14.Generality: All Languages Have a Grammar 15. Equality: All Grammars Are Equal 16.Changeability: Grammars Change Over Time 17. Universality: Grammars Are Alike in Basic Ways 18.Tacitness: Grammatical Knowledge Is Subconscious 19.Linguistics is defined as the study of language systems. It is the scientific study of language. 20.Historical approach:It is the study of language change. 21.Linguistic Competence: is the unconscious knowledge speakers of a language have about the system that enables them to create and understand novel utterances. 22.Performance: is the use of it. Performance is “the actual use of language in concrete situations.” 23.I-Language (internal language): which is the intrinsic linguistic knowledge within a native speaker. 24.E-Language (external language): which is the observable language—the output from a speaker. 25.Parole ('speech') refers to the concrete instances of the use of langue, including texts which provide the ordinary research material for linguistics. 26.Langue: 27.Language: is a system of communication that is non-stereotyped and non-finite; it is unlimited in its scope. 28.Grammar: to refer to a subconscious linguistic system of a particular type. Grammar makes possible the production and comprehension of a potentially unlimited number of utterances. 29.Communication and animals: Selecting a mode of communication (speech,writing, gesture). Delivering the symbols through a medium, a physical basis for communication, light, air, or ink. Decoding of the symbols to obtain the information. 30.SIGNS: Communication relies on using something to stand for something else. Words are an obvious example of this: You do not have to have a car, a sandwich, or your cousin present in order to talk about them—the words car, sandwich, and cousin stand for them instead. This same phenomenon is found in animal communication as well. 31.The signifier: A signifier is that part of a sign that stimulates at least one sense organ of the receiver of a message.A signifier can also be a picture, a photograph, a sign language gesture, or one of the many other words for tree in different languages. 32.The signified: The signified component of the sign refers to both the real world object it represents and its conceptual content. The first of these is the real world content of the sign, its extension or referent within a system of signs such as English, avian communication, or sign language. 33.Iconic signs or icons: always bear some resemblance to their referent. A photograph is an iconic sign; so too is a stylized silhouette of a female or a male on a restroom door. 34.Some iconic tokens: a. open-mouth threat by a Japanese macaque; b. park recreation signs; c. onomatopoeic words in English. 35.An indexical sign, or index, fulfils its function by pointing out its referent, typically by being a partial or representative sample of it. Indexes are not arbitrary, since their presence has in some sense been caused by their referent. For this reason it is sometimes said that there is a causal link between an indexical sign and its referent.The track of an animal, for example, points to the existence of the animal by representing a part of it. The presence of smoke is an index of fire. 36.Symbolic signs: bear an arbitrary relationship to their referents and in this way are distinct from both icons and indexes. Human language is highly symbolic in that the vast majority of its signs bear no inherent resemblance or causal connection to their referents, as the following words show. 37.Mixed signs Signs: are not always exclusively of one type or another. Symptomatic signs, for example, may have iconic properties, as when a dog opens its mouth in a threat to bite. Symbolic signs such as traffic lights are symptomatic in that they reflect the internal state of the mechanism that causes them to change color. 38.Signals: All signs can act as signals when they trigger a specific action on the part of the receiver, as do traffic lights, words in human language such as the race starter's "Go!", or the warning calls of birds. 39.SIGN STRUCTURE: No matter what their type, signs show different kinds of structure. A basic distinction is made between graded and discrete sign structure. 40.Graded signs convey their meaning by changes in degree. A good example of a gradation in communication is voice volume. The more you want to be heard, the louder you speak along an increasing scale of loudness. There are no steps or jumps from one level to the next that can be associated with a specific change in meaning. 41.Discrete signs are distinguished from each other by categorical (stepwise) differences. There is no gradual transition from one sign to the next. The words of human language are good examples of discrete signs. 42.A VIEW OF ANIMAL COMMUNICATION ►Largely iconic ►Largely symptomatic ►Little arbitrary ►Not deliberate ►Not conscious ►Not symbolic ►Stimulus boundCHARACTERISTICS 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) Every living organism has a level of organization. The different levels of organization for a complex multicellular organism, such as an owl, are shown in the figure below. FIGURE 1-2 THE SCIENCE OF LIFE 7 All 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.