STS SCIENCE TECHNOLOGY ANS SOCIETY, Lecture notes of Mathematics

Download STS SCIENCE TECHNOLOGY ANS SOCIETY and more Lecture notes Mathematics in PDF only on Docsity! Prof. Richelle O. Tuvillo Team Leader/Coordinator Authors/Contributors: Dr. Larry D. Buban Dr. Anita Estela M. Monroy Dr. Harlan C. Dureza Ms. Vivien Mei C. Reyes Prof. Eileen L. Loreno Dr. Stephen G. Sabinay Dr. Grace A. Manajero Dr. Agatha Z. Senina College of Arts and Sciences Physical Science Department Module in NSCI 110: Science, Technology and Society Dr. Larry D. Buban Team Editor 1 Physicsal Science Department Dr. Harlan C. Dureza Unit 1: Introduction to Science, Technology and Society NSCI 110 2 Physicsal Science Department How well did you do? How do you feel about the test? Did it make you feel confident or insecure? Your feelings will be your guide to go slow or breezw through this module. Here is the answer key and category to your pre-test. A perfect 10 makes you Science Enthusiast. Please continue to study this module as a review. If you go lower than 10, studying this module is a must. 7-9 Science Imitator 4-6 Science Aspirant 0-3 Science Hopeful 1. False 6. False 2. False 7. D 3. True 8. B 4. True 9. A 5. False 10. B 5 Physicsal Science Department UNIT 1. Introduction to Science, Technology and Society Lesson 1. Nature of Science (Week 2) Introduction: Over the course of human history, people have developed many interconnected and validated ideas about the physical, biological, psychological, and social worlds. Those ideas have enabled successive generations to achieve an increasingly comprehensive and reliable understanding of the human species and its environment. The means used to develop these ideas are particular ways of observing, thinking, experimenting, and validating. These ways represent a fundamental aspect of the nature of science and reflect how science tends to differ from other modes of knowing. It is the union of science, mathematics, and technology that forms the scientific endeavour and that makes it so successful. Although each of these human enterprises has a character and history of its own, each is dependent on and reinforces the others. Accordingly, the first three chapters of recommendations draw portraits of science, mathematics, and technology that emphasize their roles in the scientific endeavour and reveal some of the similarities and connections among them. This lesson lays out recommendations for what knowledge of the way science works is requisite for scientific literacy. The chapter focuses on three principal subjects: the scientific world view, scientific methods of inquiry, and the nature of the scientific enterprise. Further discussions consider ways in which mathematics and technology differ from science in general and views of the world as depicted by current science; Historical Perspectives, covers key episodes in the development of science; and Common Themes, pulls together ideas that cut across all these views of the world. 6 Physicsal Science Department Activate your Prior Knowledge This time relate your prior knowledge to the lesson. Read on the story of Galileo as a scientist who faced opposition for his science theories or investigations. Galileo’s story Like almost everyone in sixteenth century Italy, where Galileo was born, Galileo was taught that Earth was the centre of the Universe and that other heavenly bodies were smooth, shining spheres – perfect examples of God’s creation. According to the Church, any other belief would be contrary to what it said in the Bible, and therefore heresy. However, when Galileo used his telescope to study the Moon, he observed no smoothness, but what looked like mountains and valleys. By focusing on the boundary between the dark part of the Moon and the area lit by the Sun where shadows were longest, and measuring the shadows there, he could calculate the heights of some of the mountains. He realised that the surface of the Moon was very jagged and rocky. He also thought that the dark, smoother spots on the Moon indicated seas. All these observations went right against current concepts about the Moon – and they supported the forbidden belief that there were other worlds like the Earth, a belief for which Bruno had been convicted and burnt to death. As Galileo improved his telescopes, he was also able to observe Jupiter. He determined that the four ‘stars’ that moved with it could not be fixed stars but were four moons. Learning Outcomes: 1. understood and explained how science works, what exactly science explained. 2. discussed where does science begin and end? 3. explained the development of many interconnected and validated ideas about the physical, biological, psychological, and social worlds. 4. understood that the means used to develop ways of observing, thinking, experimenting, and validating. These ways represent a fundamental aspect of the nature of science and reflect how science tends to differ from other modes of knowing. At the end of this lesson the students must have, 7 Physicsal Science Department Acquire New Knowledge This part will present the ideas aligned with the objectives of the lesson. THE SCIENTIFIC WORLD VIEW Scientists share certain basic beliefs and attitudes about what they do and how they view their work. These have to do with the nature of the world and what can be learned about it. The World Is Understandable Science presumes that the things and events in the universe occur in consistent patterns that are comprehensible through careful, systematic study. Scientists believe that through the use of the intellect, and with the aid of instruments that extend the senses, people can discover patterns in all ofnature. Science also assumes that the universe is, as its name implies, a vast single system in which the basic rules are everywhere the same. Knowledge gained from studying one part of the universe is applicable to other parts. For instance, the same principles of motion and gravitation that explain the motion of falling objects on the surface of the earth also explain the motion of the moon and the planets. With some modifications over the years, the same principles of motion have applied to other forces—and to the motion of everything, from the smallest nuclear particles to the most massive stars, from sailboats to space vehicles, from bullets to light rays. 10 Physicsal Science Department Scientific Ideas Are Subject To Change Science is a process for producing knowledge. The process depends both on making careful observations of phenomena and on inventing theories for making sense out of those observations. Change in knowledge is inevitable because new observations may challenge prevailing theories. No matter how well one theory explains a set of observations, it is possible that another theory may fit just as well or better, or may fit a still wider range of observations. In science, the testing and improving and occasional discarding of theories, whether new or old, go on all the time. Scientists assume that even if there is no way to secure complete and absolute truth, increasingly accurate approximations can be made to account for the world and how it works. Scientific Knowledge Is Durable Although scientists reject the notion of attaining absolute truth and accept some uncertainty as part of nature, most scientific knowledge is durable. The modification of ideas, rather than their outright rejection, is the norm in science, as powerful constructs tend to survive and grow more precise and to become widely accepted. For example, in formulating the theory of relativity, Albert Einstein did not discard the Newtonian laws of motion but rather showed them to be only an approximation of limited application within a more general concept. (The National Aeronautics and Space Administration uses Newtonian mechanics, for instance, in calculating satellite trajectories.) Moreover, the growing ability of scientists to make accurate predictions about natural phenomena provides convincing evidence that we really are gaining in our understanding of how the world works. Continuity and stability are as characteristic of science as change is, and confidence is as prevalent as tentativeness. 11 Physicsal Science Department Science Cannot Provide Complete Answers to All Questions There are many matters that cannot usefully be examined in a scientific way. There are, for instance, beliefs that—by their very nature—cannot be proved or disproved (such as the existence of supernatural powers and beings, or the true purposes of life). In other cases, a scientific approach that may be valid is likely to be rejected as irrelevant by people who hold to certain beliefs (such as in miracles, fortune-telling, astrology, and superstition). Nor do scientists have the means to settle issues concerning good and evil, although they can sometimes contribute to the discussion of such issues by identifying the likely consequences of particular actions, which may be helpful in weighing alternatives. SCIENTIFICINQUIRY Fundamentally, the various scientific disciplines are alike in their reliance on evidence, the use of hypothesis and theories, the kinds of logic used, and much more. Nevertheless, scientists differ greatly from one another in what phenomena they investigate and in how they go about their work; in the reliance they place on historical data or on experimental findings and on qualitative or quantitative methods; in their recourse to fundamental principles; and in how much they draw on the findings of other sciences. Still, the exchange of techniques, information, and concepts goes on all the time among scientists, and there are common understandings among them about what constitutes an investigation that is scientifically valid. Scientific inquiry is not easily described apart from the context of particular investigations. There simply is no fixed set of steps that scientists always follow, no one path that leads them unerringly to scientific knowledge. There are, however, certain features of science that give it a distinctive character as a mode of inquiry. Although those features are especially characteristic of the work of professional scientists, everyone can exercise them in thinking scientifically about many matters of interest in everyday life. Science Demands Evidence Sooner or later, the validity of scientific claims is settled by referring to observations of phenomena. Hence, scientists concentrate on getting accurate data. Such evidence is obtained by observations and measurements taken in situations that range from natural settings (such as a forest) to completely contrived ones (such as the laboratory). To make their observations, scientists use their own senses, instruments (such as microscopes) that enhance those senses, and instruments that tap characteristics quite different from what humans can sense (such as magnetic fields). Scientists observe passively (earthquakes, bird migrations), make collections (rocks, shells), and actively probe the world (as by boring into the earth's crust or administering experimental medicines). In some circumstances, scientists can control conditions deliberately and precisely to obtain their evidence. They may, for example, control the temperature, change the concentration of chemicals, or choose which organisms mate with which others. By varying just one condition at a time, they can hope to identify its exclusive effects on what happens, uncomplicated by changes in other conditions. 12 Physicsal Science Department possible bias in their own work as in that of other scientists, although such objectivity is not always achieved. One safeguard against undetected bias in an area of study is to have many different investigators or groups of investigators working in it. Science Is Not Authoritarian It is appropriate in science, as elsewhere, to turn to knowledgeable sources of information and opinion, usually people who specialize in relevant disciplines. But esteemed authorities have been wrong many times in the history of science. In the long run, no scientist, however famous or highly placed, is empowered to decide for other scientists what is true, for none are believed by other scientists to have special access to the truth. There are no pre-established conclusions that scientists must reach on the basis of their investigations. In the short run, new ideas that do not mesh well with mainstream ideas may encounter vigorous criticism, and scientists investigating such ideas may have difficulty obtaining support for their research. Indeed, challenges to new ideas are the legitimate business of science in building valid knowledge. Even the most prestigious scientists have occasionally refused to accept new theories despite there being enough accumulated evidence to convince others. In the long run, however, theories are judged by their results: When someone comes up with a new or improved version that explains more phenomena or answers more important questions than the previous version of the scientific law, the newer one eventually takes the place of the older one. Nature of the Scientific Enterprise Science as an enterprise has individual, social, and institutional dimensions. Scientific activity is one of the main features of the contemporary world and, perhaps more than any other, distinguishes our times from earlier centuries. Science Is a Complex Social Activity Scientific work involves many individuals doing many different kinds of work and goes on to some degree in all nations of the world. Men and women of all ethnic and national backgrounds participate in science and its applications. These people— scientists and engineers, mathematicians, physicians, technicians, computer programmers, librarians, and others—may focus on scientific knowledge either for its own sake or for a particular practical purpose, and they may be concerned with data gathering, theory building, instrument building, or communicating. As a social activity, science inevitably reflects social values and viewpoints. The history of economic theory, for example, has paralleled the development of ideas of social justice—at one time, economists considered the optimum wage for workers to be no more than what would just barely allow the workers to survive. Before the twentieth century, and well into it, women and people of different race were essentially excluded from most of science by restrictions on their education and employment opportunities; the remarkable few who overcame those obstacles were even then likely to have their work belittled by the science establishment. 15 Physicsal Science Department The direction of scientific research is affected by informal influences within the culture of science itself, such as prevailing opinion on what questions are most interesting or what methods of investigation are most likely to be fruitful. Elaborate processes involving scientists themselves have been developed to decide which research proposals receive funding, and committees of scientists regularly review progress in various disciplines to recommend general priorities for funding. Science goes on in many different settings. Scientists are employed by universities, hospitals, business and industry, government, independent research organizations, and scientific associations. They may work alone, in small groups, or as members of large research teams. Their places of work include classrooms, offices, laboratories, and natural field settings from space to the bottom of the sea. Because of the social nature of science, the dissemination of scientific information is crucial to its progress. Some scientists present their findings and theories in papers that are delivered at meetings or published in scientific journals. Those papers enable scientists to inform others about their work, to expose their ideas to criticism by other scientists, and, of course, to stay abreast of scientific developments around the world. The advancement of information science (knowledge of the nature of information and its manipulation) and the development of information technologies (especially computer systems) affect all sciences. Those technologies speed up data collection, compilation, and analysis; make new kinds of analysis practical; and shorten the time between discovery and application. Science Is Organized Into Content Disciplines and Is Conducted in Various Institutions. Organizationally, science can be thought of as the collection of all of the different scientific fields, or from anthropology through zoology, there are dozens of such disciplines. They differ from one another in many ways, including history, phenomena studied, techniques and language used, and kinds of outcomes desired. With respect to purpose and philosophy, however, all are equally scientific and together make up the same scientific endeavour. The advantage of having disciplines is that they provide a conceptual structure for organizing research and research findings. The disadvantage is that their divisions do not necessarily match the way the world works, and they can make communication difficult. In any case, scientific disciplines do not have fixed borders. Physics shades into chemistry, astronomy, and geology, as does chemistry into biology and psychology, and so on. New scientific disciplines (astrophysics and socio-biology, for instance) are continually being formed at the boundaries of others. Some disciplines grow and break into sub disciplines, which then become disciplines in their own right. Universities, industry, and government are also part of the structure of the scientific endeavour. University research usually emphasizes knowledge for its own sake, although much of it is also directed toward practical problems. Universities, of course, are also particularly committed to educating successive generations of scientists, mathematicians, and engineers. Industries and businesses usually emphasize research directed to practical ends, but many also sponsor research that has no immediately obvious applications, partly on the premise that it will be applied fruitfully in the long run. The federal government funds much of the research in 16 Physicsal Science Department universities and in industry but also supports and conducts research in its many national laboratories and research centres. Private foundations, public-interest groups, and state governments also support research. Funding agencies influence the direction of science by virtue of the decisions they make on which research to support. Other deliberate controls on science result from federal (and sometimes local) government regulations on research practices that are deemed to be dangerous and on the treatment of the human and animal subjects used in experiments. There Are Generally Accepted Ethical Principles in the Conduct of Science. Most scientists conduct themselves according to the ethical norms of science. The strongly held traditions of accurate recordkeeping, openness, and replication, buttressed by the critical review of one's work by peers, serve to keep the vast majority of scientists well within the bounds of ethical professional behavior. Sometimes, however, the pressure to get credit for being the first to publish an idea or observation leads some scientists to withhold information or even to falsify their findings. Such a violation of the very nature of science impedes science. When discovered, it is strongly condemned by the scientific community and the agencies that fund research. Another domain of scientific ethics relates to possible harm that could result from scientific experiments. One aspect is the treatment of live experimental subjects. Modern scientific ethics require that due regard must be given to the health, comfort, and well-being of animal subjects. Moreover, research involving human subjects may be conducted only with the informed consent of the subjects, even if this constraint limits some kinds of potentially important research or influences the results. Informed consent entails full disclosure of the risks and intended benefits of the research and the right to refuse to participate. In addition, scientists must not knowingly subject co-workers, students, the neighbourhood, or the community to health or property risks without their knowledge and consent. The ethics of science also relates to the possible harmful effects of applying the results of research. The long-term effects of science may be unpredictable, but some idea of what applications are expected from scientific work can be ascertained by knowing who is interested in funding it. If, for example, the Department of Defense offers contracts for working on a line of theoretical mathematics, mathematicians may infer that it has application to new military technology and therefore would likely be subject to secrecy measures. Military or industrial secrecy is acceptable to some scientists but not to others. Whether a scientist chooses to work on research of great potential risk to humanity, such as nuclear weapons or germ warfare, is considered by many scientists to be a matter of personal ethics, not one of professional ethics. Scientists Participate in Public Affairs both as Specialists and as Citizens Scientists can bring information, insights, and analytical skills to bear on matters of public concern. Often they can help the public and its representatives to understand the likely causes of events (such as natural and technological disasters) and to 17 Physicsal Science Department Assess your Knowledge Multiple Choice. Identify the letter of the choice that best completes the statement or answers the question. 1. Which of the following is NOT a goal of science? A. to investigate and understand the natural world B. to explain events in the natural world C. to establish a collection of unchanging truths D. to use derived explanations to make useful predictions. 2. Science differs from other disciplines, such as history and the arts, because science relies on A. facts. C. testing explanations. B. observations. D. theories. 3. Scientists will never know for sure why dinosaurs became extinct. Therefore, scientists should A. stop studying dinosaurs and study only living animals. B. work to raise live dinosaurs to study. C. continue to learn as much as they can about dinosaur extinction. D. accept the current theory about dinosaur extinction as the best possible theory. 4. The work of scientists usually begins with A. testing a hypothesis. C. careful observations. B. creating experiments. D. drawing conclusions. 5. A student sees a bee on a flower. The student wonders how the bee finds flowers. This student is displaying the scientific attitude of A. creativity. C. curiosity. B. open-mindedness. D. skepticism. 6. Suppose that a scientist proposes a hypothesis about how a newly discovered virus affects humans. Other virus researchers would likely A. reject the hypothesis right away. B. change the hypothesis to fit their own findings. C. design new experiments to test the proposed hypothesis. D. assume that the hypothesis is true for all viruses. 7. Why is creativity considered a scientific attitude? A. Scientists need creativity to make good posters to explain their ideas. B. Creativity helps scientists come up with different experiments. C. Creative scientists imagine the results of experiments without doing them. D. Scientists who are creative are better at handling and training animals. 8. After a scientist publishes a paper, someone else finds evidence that the paper’s hypothesis may not be correct. The scientist is unhappy, but studies the new evidence anyway. The scientist is showing which scientific attitude? A. creativity C. curiosity B. open-mindedness D. scepticism 20 Physicsal Science Department 9. Suppose a scientist must choose whether to publish a report in a newspaper or in a peer-reviewed journal. What is a benefit of publishing in the journal? A. Other scientists will know that everything in the report is true. B. The reviewers will fix mistakes in the report’s experiment. C. The report will be published more quickly in the journal. D. The quality of the report will meet high scientific standards. 10. Who reviews articles for peer-reviewed journals? A. friends of the scientists who wrote the articles B. anonymous and independent experts C. the scientists who did the experiments D. people who paid for the experiments 11. How does sharing ideas through peer-reviewed articles help advance science? A. Peer-reviewed articles are published only when the ideas they contain have been accepted by most scientists. B. Experiments in peer-reviewed articles do not need to be repeated. C. Scientists reading the articles may come up with new questions to study. D. Ideas in the articles always support and strengthen dominant theories. 12. A scientist discovers an important breakthrough in cancer treatment. The scientist thinks the information could save thousands of lives and immediately announces the results on national television, skipping peer review. How might other scientists react to this news? A. They will be skeptical because the report was not peer-reviewed. B. They will quickly start to use the new treatment on their patients. C. They will congratulate the scientist for the discovery. D. They will denounce the work and call the scientist a fraud. 13. Suppose that a scientific idea is well-tested and can be used to make predictions in numerous new situations, but cannot explain one particular event. This idea is A. hypothesis that is incorrect. B. hypothesis that must be retested. C. theory that should be discarded. D. theory that may need revision. 21 Physicsal Science Department 14. A theory A. is always true. B. is the opening statement of an experiment. C. maybe revised or replaced. D. is a problem to be solved. 15. Which of the following is a question that can be answered by science? A. What is beauty? B. Is it ethical to do experiments on animals? C. How does DNA influence a person’s health? D. Do people watch too much television? 16. A personal preference or point of view is A. a bias. B. a theory. C. a hypothesis. D. an inference. 17. How does society help science advance? A. Society’s biases steer scientists toward studying certain ideas. B. Society produces technology that can be used in science. C. Society’s morals help scientists make good decisions. D. Society raises questions that science can help answer.____ 18. How does studying science help you be a better member of society? A. Learning the biases of science will help you know what is right or wrong. B. Understanding how science works will help you make better decisions. C. Memorizing science facts will help you become more intelligent. D. Knowing science will help you live without the aid of technology.____ 19. Which of the following is NOT a way that science influences society? A. Science provides answers to some of society’s practical problems. B. Science gives society answers to difficult ethical issues. C. Science advances technology that is useful to society. D. Science increases society’s understanding of how people affect the environment. 20. Scientists often try to repeat each other’s results. Which of the following should a scientist do to make it easier for others to replicate his or her experiment? A. Not use a control to save time. B. Collect only one set of data. C. Skip peer-review so the results are available sooner. D. Use the metric system when communicating procedures and results 22 Physicsal Science Department How well did you do? How do you feel about the test? Did it make you feel confident or insecure? Your feelings will be your guide to go slow or breezy through this module. Here is the answer key and category to your pre-test. A perfect 10 makes you Science Enthusiast. Please continue to study this module as a review. If you go lower than 10, studying this module is a must. 7-9 Science Imitator 4-6 Science Aspirant 0-3 Science Hopeful 1. C 6. C 2. D 7. A 3. B 8. C 4. A 9. A 5. D 10. A 25 Physicsal Science Department UNIT 1. Science and Its Conceptual Foundations Lesson 2. Nature of Mathematics Introduction: Mathematics relies on both logic and creativity, and it is pursued both for a variety of practical purposes and for its intrinsic interest. For some people, and not only professional mathematicians, the essence of mathematics lies in its beauty and its intellectual challenge. For others, including many scientists and engineers, the chief value of mathematics is how it applies to their own work. Because mathematics plays such a central role in modern culture, some basic understanding of the nature of mathematics is requisite for scientific literacy. To achieve this, students need to perceive mathematics as part of the scientific endeavour, comprehend the nature of mathematical thinking, and become familiar with key mathematical ideas and skills. The discussion focuses on mathematics as part of the scientific endeavour and then on mathematics as a process, or way of thinking. Learning Outcome: 1. understood the nature and importance of mathematics as an applied science. At the end of this lesson the students must have, 26 Physicsal Science Department Activate your Prior Knowledge This time relate your prior knowledge to the lesson. Do you agree with the statement? Why or why not? 1. Leopold Kronecker once said: 2. Euclid once said: 27 Physicsal Science Department Mathematics and technology have also developed a fruitful relationship with each other. The mathematics of connections and logical chains, for example, has contributed greatly to the design of computer hardware and programming techniques. Mathematics also contributes more generally to engineering, as in describing complex systems whose behavior can then be simulated by computer. In those simulations, design features and operating conditions can be varied as a means of finding optimum designs. For its part, computer technology has opened up whole new areas in mathematics, even in the very nature of proof, and it also continues to help solve previously daunting problems. Using mathematics to express ideas or to solve problems involves at least three phases: (1) representing some aspects of things abstractly, (2) manipulating the abstractions by rules of logic to find new relationships between them, and (3) seeing whether the new relationships say something useful about the original things. 30 Physicsal Science Department Abstraction and Symbolic Representation Mathematical thinking often begins with the process of abstraction—that is, noticing a similarity between two or more objects or events. Aspects that they have in common, whether concrete or hypothetical, can be represented by symbols such as numbers, letters, other marks, diagrams, geometrical constructions, or even words. Whole numbers are abstractions that represent the size of sets of things and events or the order of things within a set. The circle as a concept is an abstraction derived from human faces, flowers, wheels, or spreading ripples; the letter A may be an abstraction for the surface area of objects of any shape, for the acceleration of all moving objects, or for all objects having some specified property; the symbol + represents a process of addition, whether one is adding apples or oranges, hours, or miles per hour. And abstractions are made not only from concrete objects or processes; they can also be made from other abstractions, such as kinds of numbers (the even numbers, for instance). 31 Physicsal Science Department Such abstraction enables mathematicians to concentrate on some features of things and relieves them of the need to keep other features continually in mind. As far as mathematics is concerned, it does not matter whether a triangle represents the surface area of a sail or the convergence of two lines of sight on a star; mathematicians can work with either concept in the same way. The resulting economy of effort is very useful—provided that in making an abstraction, care is taken not to ignore features that play a significant role in determining the outcome of the events being studied. Manipulating Mathematical Statements After abstractions have been made and symbolic representations of them have been selected, those symbols can be combined and recombined in various ways according to precisely defined rules. Sometimes that is done with a fixed goal in mind; at other times it is done in the context of experiment or play to see what happens. Sometimes an appropriate manipulation can be identified easily from the intuitive meaning of the constituent words and symbols; at other times a useful series of manipulations has to be worked out by trial and error. Typically, strings of symbols are combined into statements that express ideas or propositions. For example, the symbol A for the area of any square may be used with the symbol s for the length of the square's side to form the proposition A = s2. This equation specifies how the area is related to the side—and also implies that it depends on nothing else. The rules of ordinary algebra can then be used to discover that if the length of the sides of a square is doubled, the square's area becomes four times as great. More generally, this knowledge makes it possible to find out what happens to the area of a square no matter how the length of its sides is changed, and conversely, how any change in the area affects the sides. Mathematical insights into abstract relationships have grown over thousands of years, and they are still being extended—and sometimes revised. Although they began in the concrete experience of counting and measuring, they have come through many layers of abstraction and now depend much more on internal logic than on mechanical demonstration. In a sense, then, the manipulation of abstractions is much like a game: Start with some basic rules, then make any moves that fit those rules—which includes inventing additional rules and finding new connections between old rules. The test for the validity of new ideas is whether they are consistent and whether they relate logically to the other rules. 32 Physicsal Science Department Answer Key Let’s check your answers. Fill in the blank 1. Mathematics 2. Abstraction 3. Theoretical mathematics 4. Symbols 5. Consistent Short response. Are you satisfied with your score? If you are not satisfied with the feedback, you may then go back to some points that you may have missed. You will now proceed to the next lesson. 35 Physicsal Science Department UNIT 1. Science and Its Conceptual Foundations Lesson 3. Nature of Technology (Week 3) How Much Do You Know? Let’s check your knowledge relative to the lesson. TRUE or FALSE. Write the word true if the statement is correct. 1. Because they ensure that an entire system functions properly, controls are complex devices. 2. A ladder is an example of a technological invention. 3. Biologists, chemists, and physicists are all technologists. 4. When technologists can't include everything they want in a design, they are forced to make trade-offs, exchanges of options for better ones. 5. Technologically literate people understand how technological processes work and how products are made. MULTIPLE CHOICE. Identify the letter of the choice that best completes the statement or answers the question. 6. To observe and record the events around them, scientists use the process of ____. A. Technology C. scientific inquiry B. scientific literacy D. designing 7. Technology extends people's natural _____. A. Resources C. abilities B. Inclinations D. innovations 8. Which of the following is NOT an example of a new problem created by existing technology? A. illness caused by contaminated food B. noise pollution from automobile traffic C. waste created by disposable products D. eyestrain from computer use Write false if the statement is incorrect. 36 Physicsal Science Department 9. One example of a recent technological innovation is _______, which is used to produce foods that stay fresh longer. A. Mechanical engineering C. Cloning B. Genetic Engineering D. Cancer Treatment 10. Technologically literate people understand that the laws of nature impose _____ on what technology can do. A. Limit C. Freedom B. Choices D. Unlimited resources 37 Physicsal Science Department Activate your Prior Knowledge This time relate your prior knowledge to the lesson. Consider the downsides of the modern technology below. 1. Cell Phones 2. Virtual Reality Headset 40 Physicsal Science Department Acquire New Knowledge This part will present the ideas aligned with the objectives of the lesson. TECHNOLOGY AND SCIENCE Technology Draws on Science and Contributes to it. In earlier times, technology grew out of personal experience with the properties of things and with the techniques for manipulating them, out of know-how handed down from experts to apprentices over many generations. The know-how handed down today is not only the craft of single practitioners but also a vast literature of words, numbers, and pictures that describe and give directions. But just as important as accumulated practical knowledge is the contribution to technology that comes from understanding the principles that underlie how things behave—that is, from scientific understanding. Engineering, the systematic application of scientific knowledge in developing and applying technology, has grown from a craft to become a science in itself. Scientific knowledge provides a means of estimating what the behavior of things will be even before we make them or observe them. Moreover, science often suggests new kinds of behavior that had not even been imagined before, and so leads to new technologies. Engineers use knowledge of science and technology, together with strategies of design, to solve practical problems. In return, technology provides the eyes and ears of science—and some of the muscle, too. The electronic computer, for example, has led to substantial progress in the study of weather systems, demographic patterns, gene structure, and other complex systems that would not have been possible otherwise. Technology is essential to science for purposes of measurement, data collection, treatment of samples, computation, transportation to research sites (such as Antarctica, the moon, and the ocean floor), sample collection, protection from hazardous materials, and communication. More and more, new instruments and techniques are being developed through technology that make it possible to advance various lines of scientific research. Technology does not just provide tools for science, however; it also may provide motivation and direction for theory and research. The theory of the conservation of energy, for example, was developed in large part because of the technological problem of increasing the efficiency of commercial steam engines. The mapping of the locations of the entire set of genes in human DNA has been motivated by the technology of genetic engineering, which both makes such mapping possible and provides a reason for doing so. As technologies become more sophisticated, their links to science become stronger. In some fields, such as solid-state physics (which involves transistors and superconductors), the ability to make something and the ability to study it are so interdependent that science and engineering can scarcely be separated. New technology often requires new understanding; new investigations often require new technology. 41 Physicsal Science Department Engineering Combines Scientific Inquiry and Practical Values The component of technology most closely allied to scientific inquiry and to mathematical modelling is engineering. In its broadest sense, engineering consists of construing a problem and designing a solution for it. The basic method is to first devise a general approach and then work out the technical details of the construction of requisite objects (such as an automobile engine, a computer chip, or a mechanical toy) or processes (such as irrigation, opinion polling, or product testing). Much of what has been said about the nature of science applies to engineering as well, particularly the use of mathematics, the interplay of creativity and logic, the eagerness to be original, the variety of people involved, the professional specialties, public responsibility, and so on. Indeed, there are more people called engineers than people called scientists, and many scientists are doing work that could be described as engineering as well as science. Similarly, many engineers are engaged in science. Scientists see patterns in phenomena as making the world understandable; engineers also see them as making the world manipulable. Scientists seek to show that theories fit the data; mathematicians seek to show logical proof of abstract connections; engineers seek to demonstrate that designs work. Scientists cannot provide answers to all questions; mathematicians cannot prove all possible connections; engineers cannot design solutions for all problems. But engineering affects the social system and culture more directly than scientific research, with immediate implications for the success or failure of human enterprises and for personal benefit and harm. Engineering decisions, whether in designing an airplane bolt or an irrigation system, inevitably involve social and personal values as well as scientific judgments. 42 Physicsal Science Department gas used in their cooling systems may have substantial adverse effects on the earth's atmosphere. Some side effects are unexpected because of a lack of interest or resources to predict them. But many are not predictable even in principle because of the sheer complexity of technological systems and the inventiveness of people in finding new applications. Some unexpected side effects may turn out to be ethically, aesthetically, or economically unacceptable to a substantial fraction of the population, resulting in conflict between groups in the community. To minimize such side effects, planners are turning to systematic risk analysis. For example, many communities require by law that environmental impact studies be made before they will consider giving approval for the introduction of a new hospital, factory, highway, waste-disposal system, shopping mall, or other structure. Risk analysis, however, can be complicated. Because the risk associated with a particular course of action can never be reduced to zero, acceptability may have to be determined by comparison to the risks of alternative courses of action, or to other, more familiar risks. People's psychological reactions to risk do not necessarily match straightforward mathematical models of benefits and costs. People tend to perceive a risk as higher if they have no control over it (smog versus smoking) or if the bad events tend to come in dreadful peaks (many deaths at once in an airplane crash versus only a few at a time in car crashes). Personal interpretation of risks can be strongly influenced by how the risk is stated—for example, comparing the probability of dying versus the probability of surviving, the dreaded risks versus the readily acceptable risks, the total costs versus the costs per person per day, or the actual number of people affected versus the proportion of affected people. 45 Physicsal Science Department All Technological Systems Can Fail Most modern technological systems, from transistor radios to airliners, have been engineered and produced to be remarkably reliable. Failure is rare enough to be surprising. Yet the larger and more complex a system is, the more ways there are in which it can go wrong—and the more widespread the possible effects of failure. A system or device may fail for different reasons: because some part fails, because some part is not well matched to some other, or because the design of the system is not adequate for all the conditions under which it is used. One hedge against failure is overdesign— that is, for example, making something stronger or bigger than is likely to be necessary. Another hedge is redundancy—that is, building in one backup system or more to take over in case the primary one fails. If failure of a system would have very costly consequences, the system may be designed so that its most likely way of failing would do the least harm. Examples of such "fail-safe" designs are bombs that cannot explode when the fuse malfunctions; automobile windows that shatter into blunt, connected chunks rather than into sharp, flying fragments; and a legal system in which uncertainty leads to acquittal rather than conviction. Other means of reducing the likelihood of failure include improving the design by collecting more data, accommodating more variables, building more realistic working models, running computer simulations of the design longer, imposing tighter quality control, and building in controls to sense and correct problems as they develop. All of the means of preventing or minimizing failure are likely to increase cost. But no matter what precautions are taken or resources invested, risk of technological failure can never be reduced to zero. Analysis of risk, therefore, involves estimating a probability of occurrence for every undesirable outcome that can be foreseen—and also estimating a measure of the harm that would be done if it did occur. The expected importance of each risk is then estimated by combining its probability and its measure of harm. The relative risk of different designs can then be compared in terms of the combined probable harm resulting from each. ISSUES IN TECHNOLOGY The Human Presence The earth's population has already doubled three times during the past century. Even at that, the human presence, which is evident almost everywhere on the earth, has had a greater impact than sheer numbers alone would indicate. We have developed the capacity to dominate most plant and animal species—far more than any other species can—and the ability to shape the future rather than merely respond to it. 46 Physicsal Science Department Use of that capacity has both advantages and disadvantages. On the one hand, developments in technology have brought enormous benefits to almost all people. Most people today have access to goods and services that were once luxuries enjoyed only by the wealthy—in transportation, communication, nutrition, sanitation, health care, entertainment, and so on. On the other hand, the very behaviour that made it possible for the human species to prosper so rapidly has put us and the earth's other living organisms at new kinds of risk. The growth of agricultural technology has made possible a very large population but has put enormous strain on the soil and water systems that are needed to continue sufficient production. Our antibiotics cure bacterial infection, but may continue to work only if we invent new ones faster than resistant bacterial strains emerge. Our access to and use of vast stores of fossil fuels have made us dependent on a non-renewable resource. In our present numbers, we will not be able to sustain our way of living on the energy that current technology provides, and alternative technologies may be inadequate or may present unacceptable hazards. Our vast mining and manufacturing efforts produce our goods, but they also dangerously pollute our rivers and oceans, soil, and atmosphere. Already, by-products of Industrialization in the atmosphere may be depleting the ozone layer, which screens the planet's surface from harmful ultraviolet rays, and may be creating a build-up of carbon dioxide, which traps heat and could raise the planet's average temperatures significantly. The environmental consequences of a nuclear war, among its other disasters, could alter crucial aspects of all life on earth. From the standpoint of other species, the human presence has reduced the amount of the earth's surface available to them by clearing large areas of vegetation; has interfered with their food sources; has changed their habitats by changing the temperature and chemical composition of large parts of the world environment; has destabilized their ecosystems by introducing foreign species, deliberately or accidentally; has reduced the number of living species; and in some instances has actually altered the characteristics of certain plants and animals by selective breeding and more recently by genetic engineering. What the future holds for life on earth, barring some immense natural catastrophe, will be determined largely by the human species. The same intelligence that got us where we are—improving many aspects of human existence and introducing new risks into the world—is also our main resource for survival. 47 Physicsal Science Department Apply your Knowledge Now, let’s check what you have learned. Creative work: Design/Draw a technological project related to your course. Considering these questions does not ensure that the best decision will always be made, but the failure to raise key questions will almost certainly result in poor decisions. The key questions concerning any proposed new technology should include the following: a) What are alternative ways to accomplish the same ends? What advantages and disadvantages are there to the alternatives? b) What trade-offs would be necessary between positive and negative side effects of each? c) Who are the main beneficiaries? Who will receive few or no benefits? d) Who will suffer as a result of the proposed new technology? e) How long will the benefits last? Will the technology have other applications? f) Whom will they benefit? g) What will the proposed new technology cost to build and operate? h) How does that compare to the cost of alternatives? i) Will people other than the beneficiaries have to bear the costs? j) Who should underwrite the development costs of a proposed new technology? i) How will the costs change over time? J) What will the social costs be? k) What risks are associated with the proposed new technology? l) What risks are associated with not using it? Who will be in greatest danger? m) What risk will the technology present to other species of life and to the environment? In the worst possible case, what trouble could it cause? n) Who would be held responsible? o) How could the trouble be undone or limited? p) What people, materials, tools, knowledge, and know-how will be needed to build, install, and operate the proposed new technology? q) Are they available? If not, how will they be obtained, and from where? r) What energy sources will be needed for construction or manufacture, and also for operation? s) What resources will be needed to maintain, update, and repair the new technology? t) What will be done to dispose safely of the new technology's waste materials? As it becomes obsolete or worn out, how will it be replaced? And finally, u) What will become of the material of which it was made and the people whose jobs depended on it? 50 Physicsal Science Department Assess your Knowledge Some Questions to Work with… 1. Aside from communication, what other aspects of society is/are being influence by the information age? How? 2. What other technological advancements can be developed in the future? Explain. 3. How would you reconcile the emerging needs of human beings regarding their health and the need to protect the growth of biodiversity? 4. Do you think that Earth can exist without human beings for it to be in a continuous growing process? 5. What are small ways that you think would promote safekeeping our biodiversity? What do you think are the common human activities that can harm biodiversity? Why? What would be the consequences if these human activities might be stopped and prohibited? Why? 6. How would you reconcile the advantages and disadvantages that GMO’s bring to humans? 7. What are the contributions of Nanotechnology for the improvement and sustainability of the environment? 8. Would you subject yourself to gene therapy without its 100% assurance of effectiveness or future negative side effects? 9. What significant contribution can individuals make in response to climate change? 10. What should be the significant contribution of the society as well as the government in mitigating the hazards caused by climate change? 51 Physicsal Science Department Answer Key Your responses will be marked using the rubric. Criteria Unsatisfactory 0 pts Needs Improvement 5 pts Satisfactory 15 pts Outstanding 25 pts Content & Develop ment - Content is incomplete. - Major points are not clear. -Specific examples are not used. - Content is not comprehensive and /or persuasive. - Major points are addressed, but not well supported. - Responses are inadequate or do not address topic. -Specific examples do not support topic. - Content is accurate and persuasive. - Major points are stated. - Responses are adequate and address topic. - Content is clear. -Specific examples are used. - Content is comprehensive, accurate, and persuasive. - Major points are stated clearly and are well supported. - Responses are excellent, timely and address topic. - Content is clear. -Specific examples are used. Organizat ion & Structure - Organization and structure detract from the message. - Writing is disjointed and lacks transition of thoughts. - Structure of the paper is not easy to follow. - Transitions need improvement. - Conclusion is missing, or if provided, does not flow from the body of the paper. - Structure is mostly clear and easy to follow. - Transitions are present. - Conclusion is logical. -Structure of the paper is clear and easy to follow. - Transitions are logical and maintain the flow of thought throughout the paper. - Conclusion is logical and flows from the body of the paper. Grammar , Punctuati on & Spelling - Paper contains numerous grammatical, punctuation, and spelling errors. - Paper contains few grammatical, punctuation and spelling errors. - Rules of grammar, usage, and punctuation are followed with minor errors. Spelling is correct. - Rules of grammar, usage, and punctuation are followed; spelling is correct. Are you satisfied with your score? If you are not satisfied with the feedback, you may then go back to some points that you may have missed. You will now proceed to the next lesson. 52 Physicsal Science Department How well did you do? How do you feel about the test? Did it make you feel confident or insecure? Your feelings will be your guide to go slow or breezw through this module. Here is the answer key and category to your pre-test. A perfect 10 makes you Science Enthusiast. Please continue to study this module as a review. If you go lower than 10, studying this module is a must. 7-9 Science Imitator 4-6 Science Aspirant 0-3 Science Hopeful 1. C 6. B 2. D 7. D 3. A 8. D 4. A 9. B 5. A 10. D 55 Physicsal Science Department UNIT 1. Science and Its Conceptual Foundations Lesson 4. The Physical Setting Introduction: Humans have never lost interest in trying to find out how the universe is put together, how it works, and where they fit in the cosmic scheme of things. The development of our understanding of the architecture of the universe is surely not complete, but we have made great progress. Given a universe that is made up of distances too vast to reach and of particles too small to see and too numerous to count, it is a tribute to human intelligence that we have made as much progress as we have in accounting for how things fit together. All humans should participate in the pleasure of coming to know their universe better. This discussion consists of recommendations for basic knowledge about the overall structure of the universe and the physical principles on which it seems to run, with emphasis on the earth and the solar system. It focuses on two principal subjects: the structure of the universe and the major processes that have shaped the planet earth, and the concepts with which science describes the physical world in general— organized for convenience under the headings of matter, energy, motion, and forces. Learning Outcome: 1. understood how the universe had been put together and how it works. At the end of this lesson the students must have: 56 Physicsal Science Department Activate your Prior Knowledge This time relate your prior knowledge to the lesson. The earth is a perfect place to live but WHY DO YOU THINK THIS YOUNG DREAMER WISH TO LIVE IN MARS, INSTEAD? For Alyssa Carson, colonizing Mars is just the first step in saving the human race. The 18-year-old astrobiology student at Florida Tech remembers when she was nine years old, she had the opportunity to meet and speak to former NASA astronaut Sandra Magnus at the Sally Ride Science Festival in Louisiana. "I asked her, 'When did you decide to become an astronaut,' and she told me that she was around nine or so," Carson, a freshman at Florida Tech told FLORIDA TODAY. Already engrossed in all things space, the brief encounter with Magnus gave Carson the extra push to continue to pursue a career in the space industry. "She just kind of inspired me that you can decide what you want to do at a young age, work hard and it can actually become a reality," Carson said. She's now 18 years old, with a pilot's license, is "certified" to go to space and hopes to be a part of the crew that lays down the foundation to colonize the red planet. 57 Physicsal Science Department its surface or from satellites orbiting above the surface. What we know about the evolution of the sun and planets comes from studying the radiation from a small sample of stars, visual features of the planets, and samples of material (such as rock, meteorites, and moon and Mars scrapings), and imagining how they got to be the way they are. THE EARTH We live on a fairly small planet, the third from the sun in the only system of planets definitely known to exist (although similar systems are likely to be common in the universe). Like that of all planets and stars, the earth's shape is approximately spherical, the result of mutual gravitational attraction pulling its material toward a common center. Unlike the much larger outer planets, which are mostly gas, the earth is mostly rock, with three-fourths of its surface covered by a relatively thin layer of water and the entire planet enveloped by a thin blanket of air. Bulges in the water layer are raised on both sides of the planet by the gravitational tugs of the moon and sun, producing high tides about twice a day along ocean shores. Similar bulges are produced in the blanket of air as well. Of all the diverse planets and moons in our solar system, only the earth appears to be capable of supporting life as we know it. The gravitational pull of the planet's mass is sufficient to hold onto an atmosphere. This thin envelope of gases evolved as a result of changing physical conditions on the earth's surface and the evolution of plant life, and it is an integral part of the global ecosystem. Altering the concentration of its natural component gases of the atmosphere, or adding new ones, can have serious consequences for the earth's life systems. The distance of the earth from the sun ensures that energy reaches the planet at a rate sufficient to sustain life, and yet not so fast that water would boil away or that molecules necessary to life would not form. Water exists on the earth in liquid, solid, and gaseous forms—a rarity among the planets (the others are either closer to the sun or too hot or farther from the sun and too cold). The motion of the earth and its position with regard to the sun and the moon have noticeable effects. The earth's one-year revolution around the sun, because of the tilt of the earth's axis, changes how directly sunlight falls on one part or another of the earth. This difference in heating different parts of the earth's surface produces seasonal variations in climate. The rotation of the planet on its axis every 24 hours produces the planet's night-and-day cycle—and (to observers on earth) makes it seem as though the sun, planets, stars, and moon are orbiting the earth. The combination of the earth's motion and the moon's own orbit around the earth, once in about 28 days, results in the phases of the moon (on the basis of the changing angle at which we see the sunlit side of the moon). The earth has a variety of climatic patterns, which consist of different conditions of temperature, precipitation, humidity, wind, air pressure, and other atmospheric phenomena. These patterns result from an interplay of many factors. The basic energy source is the heating of land, ocean, and air by solar radiation. Transfer of heat energy at the interfaces of the atmosphere with the land and oceans produces layers at different temperatures in both the air and the oceans. 60 Physicsal Science Department These layers rise or sink or mix, giving rise to winds and ocean currents that carry heat energy between warm and cool regions. The earth's rotation curves the flow of winds and ocean currents, which are further deflected by the shape of the land. The cycling of water in and out of the atmosphere plays an important part in determining climatic patterns—evaporating from the surface, rising and cooling, condensing into clouds and then into snow or rain, and falling again to the surface, where it collects in rivers, lakes, and porous layers of rock. There are also large areas on the earth's surface covered by thick ice (such as Antarctica), which interacts with the atmosphere and oceans in affecting worldwide variations in climate. The earth's climates have changed radically and they are expected to continue changing, owing mostly to the effects of geological shifts such as the advance or retreat of glaciers over centuries of time or a series of huge volcanic eruptions in a short time. But even some relatively minor changes of atmospheric content or of ocean temperature, if sustained long enough, can have widespread effects on climate. The earth has many resources of great importance to human life. Some are readily renewable, some are renewable only at great cost, and some are not renewable at all. The earth comprises a great variety of minerals, whose properties depend on the history of how they were formed as well as on the elements of which they are composed. Their abundance ranges from rare to almost unlimited. But the difficulty of extracting them from the environment is as important an issue as their abundance. A wide variety of minerals are sources for essential industrial materials, such as iron, aluminum, magnesium, and copper. Many of the best sources are being depleted, making it more and more difficult and expensive to obtain those minerals. Fresh water is an essential resource for daily life and industrial processes. We obtain our water from rivers and lakes and from water that moves below the earth's surface. This groundwater, which is a major source for many people, takes a long time to accumulate in the quantities now being used. In some places it is being depleted at a very rapid rate. Moreover, many sources of fresh water cannot be used because they have been polluted. Wind, tides, and solar radiation are continually available and can be harnessed to provide sources of energy. In principle, the oceans, atmosphere, topsoil, sea creatures, and trees are renewable resources. However, it can be enormously expensive to clean up polluted air and water, restore destroyed forests and fishing grounds, or restore or preserve eroded soils of poorly managed agricultural areas. Although the oceans and atmosphere are very large and have a great capacity to absorb and recycle materials naturally, they do have their limits. They have only a finite capacity to withstand change without generating major ecological alterations that may also have adverse effects on human activities. Processes that Shape the Earth The interior of the earth is hot, under high pressure from the weight of overlying layers, and more dense than its rocky crust. Forces within the earth cause continual changes on its surface. The solid crust of the earth—including both the continents and ocean basins—consists of separate sections that overlie a hot, almost molten layer. The separate crustal plates move on this softer layer—as much as an inch or more per year—colliding in some places, pulling apart in others. Where the crustal plates collide, they may scrape sideways, or compress the land into folds that eventually become mountain ranges (such as the Rocky Mountains and the Himalayas); or one plate may slide under the other and sink deeper into the earth. 61 Physicsal Science Department Along the boundaries between colliding plates, earthquakes shake and break the surface, and volcanic eruptions release molten rock from below, also building up mountains. Where plates separate under continents, the land sinks to form ever- widening valleys. When separation occurs in the thin regions of plates that underlie ocean basins, molten rock wells up to create ever-wider ocean floors. Volcanic activity along these mid-ocean separations may build up undersea mountains that are far higher than those rising from the land surface—sometimes thrusting above the water's surface to create mid-ocean islands. Waves, wind, water, and ice sculpt the earth's surface to produce distinctive landforms. Rivers and glacial ice carry off soil and break down rock, eventually depositing the material in sediments or carrying it in solution to the sea. Some of these effects occur rapidly and others very slowly. For instance, many of the features of the earth's surface today can be traced to the motion of glaciers back and forth across much of the northern hemisphere over a period lasting more than a million years. By contrast, the shoreline can change almost overnight—as waves erode the shores, and wind carries off loose surface material and deposits it elsewhere. Elements such as carbon, oxygen, nitrogen, and sulfur cycle slowly through the land, oceans, and atmosphere, changing their locations and chemical combinations. Minerals are made, dissolved, and remade—on the earth's surface, in the oceans, and in the hot, high-pressure layers beneath the crust. Sediments of sand and shells of dead organisms are gradually buried, cemented together by dissolved minerals, and eventually turned into solid rock again. Sedimentary rock buried deep enough may be changed by pressure and heat, perhaps melting and recrystallizing into different kinds of rock. Buried rock layers may be forced up again to become land surface and eventually even mountains. Thousands upon thousands of layers of sedimentary rock testify to the long history of the earth, and to the long history of changing life forms whose remains are found in successive layers of rock. Plants and animals reshape the landscape in many ways. The composition and texture of the soil, and consequently its fertility and resistance to erosion, are greatly influenced by plant roots and debris, bacteria, and fungi that add organic material to the soil, and by insects, worms, and burrowing animals that break it up. The presence of life has also altered the earth's atmosphere. Plants remove carbon dioxide from the air, use the carbon for synthesizing sugars, and release oxygen. This process is responsible for the oxygen in our air today. The landforms, climate, and resources of the earth's surface affect where and how people live and how human history has unfolded. At the same time, human activities have changed the earth's land surface, oceans, and atmosphere. For instance, reducing the amount of forest cover on the earth's surface has led to a dramatic increase in atmospheric carbon dioxide, which in turn may be leading to increased average temperature of the earth's atmosphere and surface. Smoke and other substances from human activity interact chemically with the atmosphere and produce undesirable effects such as smog, acid rain, and perhaps an increase in the damaging ultraviolet radiation that penetrates the atmosphere. Intensive farming has stripped land of vegetation and topsoil, creating virtual deserts in some parts of the world. 62 Physicsal Science Department Each of the elements that make up familiar substances consists of only a few naturally occurring isotopes. Most other possible isotopes of any element are unstable and, if they happen to be formed, sooner or later will decay into some isotope of another element (which may itself be unstable). The decay involves emission of particles and radiation from the nucleus—that is, radioactivity. In the materials of the earth, there are small proportions of some radioactive isotopes that were left over from the original formation of heavy elements in stars. Some were formed more recently by impacts of nuclear particles from space, or from the nuclear decay of other isotopes. Together, these isotopes produce a low level of background radiation in the general environment. It is not possible to predict when an unstable nucleus will decay. We can determine only what fraction of a collection of identical nuclei are likely to decay in a given period of time. The half-life of an unstable isotope is the time it takes for half of the nuclei in any sample of that isotope to decay; half-lives of different isotopes range from less than a millionth of a second to many millions of years. The half-life of any particular isotope is constant and unaffected by physical conditions such as pressure and temperature. Radioactivity can therefore be used to estimate the passage of time, by measuring the fraction of nuclei that have already decayed. For example, the fraction of an unstable, long-half-life isotope remaining in a sample of rock can be used to estimate how long ago the rock was formed. ENERGY TRANSFORMATIONS Energy appears in many forms, including radiation, the motion of bodies, excited states of atoms, and strain within and between molecules. All of these forms are in an important sense equivalent, in that one form can change into another. Most of what goes on in the universe—such as the collapsing and exploding of stars, biological growth and decay, the operation of machines and computers— involves one form of energy being transformed into another. Forms of energy can be described in different ways: Sound energy is chiefly the regular back-and forth motion of molecules; heat energy is the random motion of molecules; gravitational energy lies in the separation of mutually attracting masses; the energy stored in mechanical strains involves the separation of mutually attracting electric charges. Although the various forms appear very different, each can be measured in a way that makes it possible to keep track of how much of one form is converted into another. Whenever the amount of energy in one place or form diminishes, the amount in another place or form increases by an equivalent amount. Thus, if no energy leaks in or out across the boundaries of a system, the total energy of all the different forms in the system will not change, no matter what kinds of gradual or violent changes actually occur within the system. But energy does tend to leak across boundaries. In particular, transformations of energy usually result in producing some energy in the form of heat, which leaks away by radiation or conduction (such as from engines, electrical 65 Physicsal Science Department wires, hot-water tanks, our bodies, and stereo systems). Further, when heat is conducted or radiated into a fluid, currents are set up that usually enhance the transfer of heat. Although materials that conduct or radiate heat very poorly can be used to reduce heat loss, it can never be prevented completely. Therefore the total amount of energy available for transformation is almost always decreasing. For example, almost all of the energy stored in the molecules of gasoline used during an automobile trip goes, by way of friction and exhaust, into producing a slightly warmer car, road, and air. But even if such diffused energy is prevented from leaking away, it tends to distribute itself evenly and thus may no longer be useful to us. This is because energy can accomplish transformations only when it is concentrated more in some places than in others (such as in falling water, in high-energy molecules in fuels and food, in unstable nuclei, and in radiation from the intensely hot sun). When energy is transformed into heat energy that diffuses all over, further transformations are less likely. The reason that heat tends always to diffuse from warmer places to cooler places is a matter of probability. Heat energy in a material consists of the disordered motions of its perpetually colliding atoms or molecules. As very large numbers of atoms or molecules in one region of a material repeatedly and randomly collide with those of a neighboring region, there are far more ways in which their energy of random motion can end up shared about equally throughout both regions than there are ways in which it can end up more concentrated in one region. The disordered sharing of heat energy all over is therefore far more likely to occur than any more orderly concentration of heat energy in any one place. More generally, in any interactions of atoms or molecules, the statistical odds are that they will end up in more disorder than they began with. It is, however, entirely possible for some systems to increase in orderliness—as long as systems connected to them increase even more in disorderliness. The cells of a human organism, for example, are always busy increasing order, as in building complex molecules and body structures. But this occurs at the cost of increasing the disorder around us even more—as in breaking down the molecular structure of food we eat and in warming up our surroundings. The point is that the total amount of disorder always tends to increase. Different energy levels are associated with different configurations of atoms in molecules. Some changes in configuration require additional energy, whereas other changes release energy. For example, heat energy has to be supplied to start a charcoal fire (by evaporating some carbon atoms away from others in the charcoal); however, when oxygen molecules combine with the carbon atoms into the lower- energy configuration of a carbon dioxide molecule, much more energy is released as heat and light. Or a chlorophyll molecule can be excited to a higher-energy configuration by sunlight; the chlorophyll in turn excites molecules of carbon dioxide and water so they can link, through several steps, into the higher-energy configuration of a molecule of sugar (plus some regenerated oxygen). Later, the sugar molecule may subsequently interact with oxygen to yield carbon dioxide and water molecules again, transferring the extra energy from sunlight to still other molecules. It becomes evident, at the molecular level and smaller, that energy as well as matter occurs in discrete units: When energy of an atom or molecule changes from one value to another, it does so in definite jumps, with no possible values in between. These quantum effects make phenomena on the atomic scale very different from what we are familiar with. When radiation encounters an atom, it can 66 Physicsal Science Department excite the atom to a higher internal energy level only if it can supply just the right amount of energy for the step. The reverse also occurs: When the energy level of an atom relaxes by a step, a discrete amount (quantum) of radiation energy is produced. The light emitted by a substance or absorbed by a substance can therefore serve to identify what the substance is, whether the substance is in the laboratory or is on the surface of a distant star. Reactions in the nuclei of atoms involve far greater energy changes than reactions between the outer electron structures of atoms (that is, chemical reactions). When very heavy nuclei, such as those of uranium or plutonium, split into middle-weight ones, or when very light nuclei, such as those of hydrogen and helium, combine into somewhat heavier ones, large amounts of energy are released as radiation and rapidly moving particles. Fission of some heavy nuclei occurs spontaneously, producing extra neutrons that induce fission in more nuclei and so on, thus giving rise to a chain reaction. The fusion of nuclei, however, occurs only if they collide at very great speeds (overcoming the electric repulsion between them), such as the collisions that occur at the very high temperatures produced inside a star or by a fission explosion. MOTION Motion is as much a part of the physical world as matter and energy are. Everything moves—atoms and molecules; the stars, planets, and moons; the earth and its surface and everything on its surface; all living things, and every part of living things. Nothing in the universe is at rest. Since everything is moving, there is no fixed reference point against which the motion of things can be described. All motion is relative to whatever point or object we choose. Thus, a parked bus has no motion with reference to the earth's surface; but since the earth spins on its axis, the bus is moving about 1,000 miles per hour around the center of the earth. If the bus is moving down the highway, then a person walking up the aisle of the bus has one speed with reference to the bus, another with respect to the highway, and yet another with respect to the earth's center. There is no point in space that can serve as a reference for what is actually moving. Changes in motion—speeding up, slowing down, changing direction—are due to the effects of forces. Any object maintains a constant speed and direction of motion unless an unbalanced outside force acts on it. When an unbalanced force does act on an object, the object's motion changes. Depending on the direction of the force relative to the direction of motion, the object may change its speed (a falling apple) or its direction of motion (the moon in its curved orbit), or both (a fly ball). The greater the amount of the unbalanced force, the more rapidly a given object's speed or direction of motion changes; the more massive an object is, the less rapidly its speed or direction changes in response to any given force. And whenever something A exerts a force on something B, B exerts an equally strong force back on A. For example, iron nail A pulls on magnet B with the same amount of force as magnet B pulls on iron nail A—but in the opposite direction. 67 Physicsal Science Department Depending on how many of the electric charges in them are free to move, materials show great differences in how much they respond to electric forces. At one extreme, an electrically insulating material such as glass or rubber does not ordinarily allow any passage of charges through it. At the other extreme, an electrically conducting material such as copper will offer very little resistance to the motion of charges, so electric forces acting on it readily produce a current of charges. (Most electrical wires are a combination of extremes: a very good conductor covered by a very good insulator.) In fact, at very low temperatures, certain materials can become superconductors, which offer zero resistance. In between low- and high-resistance materials are semiconducting materials in which the ease with which charges move may vary greatly with subtle changes in composition or conditions; these materials are used in transistors and computer chips to control electrical signals. Water usually contains charged molecular fragments of dissolved impurities that are mobile, and so it is a fairly good conductor. Magnetic forces are very closely related to electric forces—the two can be thought of as different aspects of a single electromagnetic force. Both are thought of as acting by means of fields: an electric charge has an electric field in the space around it that affects other charges, and a magnet has a magnetic field around it that affects other magnets. What is more, moving electric charges produce magnetic fields and are affected by magnetic fields. This influence is the basis of many natural phenomena. For example, electric currents circulating in the earth's core give the earth an extensive magnetic field, which we detect from the orientation of our compass needles. The interplay of electric and magnetic forces is also the basis of much technological design, such as electric motors (in which currents produce motion), generators (in which motion produces currents), and television tubes (in which a beam of moving electric charges is bent back and forth by a periodically changing magnetic field). More generally, a changing electric field induces a magnetic field, and vice versa. Other types of forces operate only at the subatomic scale. For example, the nuclear force that holds particles together within the atomic nucleus is much stronger than the electric force, as is evident in the relatively great amounts of energy released by nuclear interactions. 70 Physicsal Science Department Apply your Knowledge Now, let’s check what you have learned. Reflect on the following questions, then answer the following questions logically. 1. How can the interplay of electric and magnetic forces in technological design? 2. How did light become a significant aid in understanding the Universe? 3. What are the balanced forces that keeps earth from motion? How and what will happened if this forces will be altered? 4. Explain the idea “energy does tend to leak across boundaries”. 5. As students in your chosen field, practically what is the significance of knowing the structure and properties of matter? Your responses will be marked using the rubric. Criteria Unsatisfactor y 0 pts Needs Improvement 5 pts Satisfactory 15 pts Outstanding 25 pts Content & Developmen t - Content is incomplete. - Major points are not clear. -Specific examples are not used. - Content is not comprehensive and /or persuasive. - Major points are addressed, but not well supported. - Responses are inadequate or do not address topic. -Specific examples do not support topic. - Content is accurate and persuasive. - Major points are stated. - Responses are adequate and address topic. - Content is clear. -Specific examples are used. - Content is comprehensive, accurate, and persuasive. - Major points are stated clearly and are well supported. - Responses are excellent, timely and address topic. - Content is clear. -Specific examples are used. Organization & Structure - Organization and structure detract from the message. - Writing is disjointed and lacks transition of thoughts. - Structure of the paper is not easy to follow. - Transitions need improvement. - Conclusion is missing, or if provided, does not flow from the body of the paper. - Structure is mostly clear and easy to follow. - Transitions are present. - Conclusion is logical. -Structure of the paper is clear and easy to follow. - Transitions are logical and maintain the flow of thought throughout the paper. - Conclusion is logical and flows from the body of the paper. Grammar, Punctuation & Spelling - Paper contains numerous grammatical, punctuation, and spelling errors. - Paper contains few grammatical, punctuation and spelling errors. - Rules of grammar, usage, and punctuation are followed with minor errors. Spelling is correct. - Rules of grammar, usage, and punctuation are followed; spelling is correct. 71 Physicsal Science Department Assess your Knowledge Multiple Choice. Identify the letter of the choice that best completes the statement or answers the question. 1. When a pair of balanced forces acts on an object, the net force that results is A. greater in size than one of the forces. B. equal to zero. C. equal in size to one of the forces. D. greater in size than both forces combined. 2. Energy from the sun reaches Earth mostly by A. convection. C.conduction. B. thermal expansion. D.radiation. 3. Which of the following universal forces is the most effective over long distances? A. Gravitational C. strong nuclear B. Magnetic D. electric 4. Which of the following statements best describes what happens when chocolate melts? A. This is a physical change, and the molecules move farther apart. B. This is a chemical change, and the molecules move farther apart. C. This is a physical change, and the molecules move closer together. D. This is a chemical change, and the molecules move closer together. 5. Which of the following is not true about acid-base indicators? A. They act as sensors of H+ by changing color. B. They account for the fact that roses are red and violets are blue. C. They are found in pH paper. D. They form the basis of the Scott test for cocaine. 72 Physicsal Science Department How well did you do? How do you feel about the test? Did it make you feel confident or insecure? Your feelings will be your guide to go slow or breezw through this module. Here is the answer key and category to your pre-test. A perfect 10 makes you Science Enthusiast. Please continue to study this module as a review. If you go lower than 10, studying this module is a must. 7-9 Science Imitator 4-6 Science Aspirant 0-3 Science Hopeful 1. D 2. B 3. C/D 4. Better health care so people are living longer New medicines are being developed so people don't die of previously fatal diseases Farmers are able to produce more food using new breeds and equipment Some religions do not permit the use of contraception 5. Animals and plants both compete for space [1 mark]. This is called territory for animals [1 mark]. As well as this, animals compete for food and mates [1 mark]. Whereas, plants compete for light and water and minerals from the soil [1 mark]. 75 Physicsal Science Department UNIT 1. Science and Its Conceptual Foundations Lesson 5. The Living Environment (Week 4) Introduction: People have long been curious about living things—how many different species there are, what they are like, where they live, how they relate to each other, and how they behave. Scientists seek to answer these questions and many more about the organisms that inhabit the earth. In particular, they try to develop the concepts, principles, and theories that enable people to understand the living environment better. Living organisms are made of the same components as all other matter, involve the same kind of transformations of energy, and move using the same basic kinds of forces. The Physical Setting, apply to life as well as to stars, raindrops, and television sets. But living organisms also have characteristics that can be understood best through the application of other principles. This discussion offers recommendations on basic knowledge about how living things function and how they interact with one another and their environment. The chapter focuses on six major subjects: the diversity of life, as reflected in the biological characteristics of the earth's organisms; the transfer of heritable characteristics from one generation to the next; the structure and functioning of cells, the basic building blocks of all organisms; the interdependence of all organisms and their environment; the flow of matter and energy through the grand-scale cycles of life; and how biological evolution explains the similarity and diversity of life. 1. discussed the basic knowledge about how living things function and how they interact with one another and their environment. Learning Outcome: At the end of this lesson tthe students must have: 76 Physicsal Science Department Activate your Prior Knowledge This time relate your prior knowledge to the lesson. Agree or disagree? What can you say about this quote? 77 Physicsal Science Department CELLS All self-replicating life forms are composed of cells—from single-celled bacteria to elephants, with their trillions of cells. Although a few giant cells, such as hens' eggs, can be seen with the naked eye, most cells are microscopic. It is at the cell level that many of the basic functions of organisms are carried out: protein synthesis, extraction of energy from nutrients, replication, and so forth. All living cells have similar types of complex molecules that are involved in these basic activities of life. These molecules interact in a soup, about 2/3 water, surrounded by a membrane that controls what can enter and leave. In more complex cells, some of the common types of molecules are organized into structures that perform the same basic functions more efficiently. In particular, a nucleus encloses the DNA and a protein skeleton helps to organize operations. In addition to the basic cellular functions common to all cells, most cells in multi-celled organisms perform some special functions that others do not. For example, gland cells secrete hormones, muscle cells contract, and nerve cells conduct electrical signals. Cell molecules are composed of atoms of a small number of elements—mainly carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur. Carbon atoms, because of their small size and four available bonding electrons, can join to other carbon atoms in chains and rings to form large and complex molecules. Most of the molecular interactions in cells occur in water solution and require a fairly narrow range of temperature and acidity. At low temperatures the reactions go too slowly, whereas high temperatures or extremes of acidity can irreversibly damage the structure of protein molecules. Even small changes in acidity can alter the molecules and how they interact. Both single cells and multicellular organisms have molecules that help to keep the cells' acidity within the necessary range. The work of the cell is carried out by the many different types of molecules it assembles, mostly proteins. Protein molecules are long, usually folded chains made from 20 different kinds of amino acid molecules. The function of each protein depends on its specific sequence of amino acids and the shape the chain takes as a consequence of attractions between the chain's parts. Some of the assembled molecules assist in replicating genetic information, repairing cell structures, helping other molecules to get in or out of the cell, and generally in catalyzing and regulating molecular interactions. In specialized cells, other protein molecules may carry oxygen, effect contraction, respond to outside stimuli, or provide material for hair, nails, and other body structures. In still other cells, assembled molecules may be exported to serve as hormones, antibodies, or digestive enzymes. The genetic information encoded in DNA molecules provides instructions for assembling protein molecules. This code is virtually the same for all life forms. Thus, for example, if a gene from a human cell is placed in a bacterium, the chemical machinery of the bacterium will follow the gene's instructions and produce the same protein that would be produced in human cells. A change in even a single atom in the DNA molecule, which may be induced by chemicals or radiation, can therefore change the protein that is produced. Such a mutation of a DNA segment may not make much difference, may fatally disrupt the operation of the cell, or may change the successful operation of the cell in a significant way (for example, it may foster uncontrolled replication, as in cancer). 80 Physicsal Science Department All the cells of an organism are descendants of the single fertilized egg cell and have the same DNA information. As successive generations of cells form by division, small differences in their immediate environments cause them to develop slightly differently, by activating or inactivating different parts of the DNA information. Later generations of cells differ still further and eventually mature into cells as different as gland, muscle, and nerve cells. Complex interactions among the myriad kinds of molecules in the cell may give rise to distinct cycles of activities, such as growth and division. Control of cell processes comes also from without: Cell behavior may be influenced by molecules from other parts of the organism or from other organisms (for example, hormones and neurotransmitters) that attach to or pass through the cell membrane and affect the rates of reaction among cell constituents. INTERDEPENDENCE OF LIFE Every species is linked, directly or indirectly, with a multitude of others in an ecosystem. Plants provide food, shelter, and nesting sites for other organisms. For their part, many plants depend upon animals for help in reproduction (bees pollinate flowers, for instance) and for certain nutrients (such as minerals in animal waste products). All animals are part of food webs that include plants and animals of other species (and sometimes the same species). The predator/prey relationship is common, with its offensive tools for predators—teeth, beaks, claws, venom, etc.—and its defensive tools for prey—camouflage to hide, speed to escape, shields or spines to ward off, irritating substances to repel. Some species come to depend very closely on others (for instance, pandas or koalas can eat only certain species of trees). Some species have become so adapted to each other that neither could survive without the other (for example, the wasps that nest only in figs and are the only insect that can pollinate them). There are also other relationships between organisms. Parasites get nourishment from their host organisms, sometimes with bad consequences for the hosts. Scavengers and decomposers feed only on dead animals and plants. And some organisms have mutually beneficial relationships—for example, the bees that sip nectar from flowers and incidentally carry pollen from one flower to the next, or the bacteria that live in our intestines and incidentally synthesize some vitamins and protect the intestinal lining from germs. But the interaction of living organisms does not take place on a passive environmental stage. Ecosystems are shaped by the nonliving environment of land and water—solar radiation, rainfall, mineral concentrations, temperature, and topography. The world contains a wide diversity of physical conditions, which creates a wide variety of environments: freshwater and oceanic, forest, desert, grassland, tundra, mountain, and many others. In all these environments, organisms use vital earth resources, each seeking its share in specific ways that are limited by other organisms. In every part of the habitable environment, different organisms vie for food, space, light, heat, water, air, and shelter. The linked and fluctuating interactions of life forms and environment compose a total ecosystem; understanding any one part of it well requires knowledge of how that part interacts with the others. The interdependence of organisms in an ecosystem often results in approximate stability over hundreds or thousands of years. As one species 81 Physicsal Science Department proliferates, it is held in check by one or more environmental factors: depletion of food or nesting sites, increased loss to predators, or invasion by parasites. If a natural disaster such as flood or fire occurs, the damaged ecosystem is likely to recover in a succession of stages that eventually results in a system similar to the original one. Like many complex systems, ecosystems tend to show cyclic fluctuations around a state of approximate equilibrium. In the long run, however, ecosystems inevitably change when climate changes or when very different new species appear as a result of migration or evolution (or are introduced deliberately or inadvertently by humans). FLOW OF MATTER AND ENERGY However complex the workings of living organisms, they share with all other natural systems the same physical principles of the conservation and transformation of matter and energy. Over long spans of time, matter and energy are transformed among living things, and between them and the physical environment. In these grand-scale cycles, the total amount of matter and energy remains constant, even though their form and location undergo continual change. Almost all life on earth is ultimately maintained by transformations of energy from the sun. Plants capture the sun's energy and use it to synthesize complex, energy- rich molecules (chiefly sugars) from molecules of carbon dioxide and water. These synthesized molecules then serve, directly or indirectly, as the source of energy for the plants themselves and ultimately for all animals and decomposer organisms (such as bacteria and fungi). This is the food web: The organisms that consume the plants derive energy and materials from breaking down the plant molecules, use them to synthesize their own structures, and then are themselves consumed by other organisms. At each stage in the food web, some energy is stored in newly synthesized structures and some is dissipated into the environment as heat produced by the energy-releasing chemical processes in cells. A similar energy cycle begins in the oceans with the capture of the sun's energy by tiny, plant- like organisms. Each successive stage in a food web captures only a small fraction of the energy content of organisms it feeds on. The elements that make up the molecules of living things are continually recycled. Chief among these elements are carbon, oxygen, hydrogen, nitrogen, sulfur, phosphorus, calcium, sodium, potassium, and iron. These and other elements, mostly occurring in energy-rich molecules, are passed along the food web and eventually are recycled by decomposers back to mineral nutrients usable by plants. Although there often may be local excesses and deficits, the situation over the whole earth is that organisms are dying and decaying at about the same rate as that at which new life is being synthesized. That is, the total living biomass stays roughly constant, there is a cyclic flow of materials from old to new life, and there is an irreversible flow of energy from captured sunlight into dissipated heat. An important interruption in the usual flow of energy apparently occurred millions of years ago when the growth of land plants and marine organisms exceeded the ability of decomposers to recycle them. The accumulating layers of energy-rich organic 82 Physicsal Science Department Apply your Knowledge Now, let’s check what you have learned. Reflect on the following questions, then answer the following questions logically. 1. Why do human beings laugh? 2. Why did human species develop to be dominant on the planet? 3. What distinguishes human brain from the other species? 4. Why do human beings perceive beauty? 5. How does evolution theory explain the existence of language and speech? 6. Why did humans start walking on two feet? 7. What is the evolutionary benefit of forming the society? Your responses will be marked using the rubric. Criteria Unsatisfactor y 0 pts Needs Improvement 5 pts Satisfactory 15 pts Outstanding 25 pts Content & Developmen t - Content is incomplete. - Major points are not clear. -Specific examples are not used. - Content is not comprehensive and /or persuasive. - Major points are addressed, but not well supported. - Responses are inadequate or do not address topic. -Specific examples do not support topic. - Content is accurate and persuasive. - Major points are stated. - Responses are adequate and address topic. - Content is clear. -Specific examples are used. - Content is comprehensive, accurate, and persuasive. - Major points are stated clearly and are well supported. - Responses are excellent, timely and address topic. - Content is clear. -Specific examples are used. Organization & Structure - Organization and structure detract from the message. - Writing is disjointed and lacks transition of thoughts. - Structure of the paper is not easy to follow. - Transitions need improvement. - Conclusion is missing, or if provided, does not flow from the body of the paper. - Structure is mostly clear and easy to follow. - Transitions are present. - Conclusion is logical. -Structure of the paper is clear and easy to follow. - Transitions are logical and maintain the flow of thought throughout the paper. - Conclusion is logical and flows from the body of the paper. Grammar, Punctuation & Spelling - Paper contains numerous grammatical, punctuation, and spelling errors. - Paper contains few grammatical, punctuation and spelling errors. - Rules of grammar, usage, and punctuation are followed with minor errors. Spelling is correct. - Rules of grammar, usage, and punctuation are followed; spelling is correct. 85 Physicsal Science Department Assess your Knowledge Multiple Choice. Identify the letter of the choice that best completes the statement or answers the question. 1. Process of selecting individuals with desired characters by man is called (a) Hybridization (b) Reproduction (c) Artificial selection (d) Natural selection 2. Which one of the following pairs are homologous organs? (a) Forelimbs of a bird and wings of a bat. (b) Wings of a bird and wings of a butterfly. (c) Pectoral fins of a fish and forelimbs of a horse. (d) Wings of a bat and wings of a cockroach. 3. The theory of evolution of species by natural selection was given by (a) Mendel (b) Darwin (c) Lamarck (d) Weismann 4. A cross between a tall pea-plant (TT) and a short pea-plant (tt) resulted in progenies that were all tall plants because (a) tallness is the recessive trait. (b) shortness is the dominant trait. (c) height of pea-plant is not governed by gene T or t. (d) tallness is the dominant trait. 5. The number of pairs of sex chromosomes in the zygote of a human being is (a) 2 (b) 3 (c) 1 (d) 4 6. A zygote which has an X-chromosome inherited from the father will develop into a (a) girl (b) boy (c) either boy or girl (d) X-chromosome does not influence the sex of a child. 86 Physicsal Science Department 7. A man with blood group A marries a woman having blood group O. What will be the blood group of the child? (a) O only (b) A only (c) AB (d) Equal chance of acquiring blood group A or blood group O. 8. What does the progeny of a tall plant with round seeds and a short plant with wrinkled seeds look like? (a) All are tall with round seeds. (b) All are short with round seeds. (c) All are tall with wrinkled seeds. (d) All are short with wrinkled seeds. 9. If a round, green seeded pea-plant (RRyy) is crossed with a wrinkled yellow seeded pea- plant (rrYY), the seeds produced in F1 generation are (a) round and green (b) round and yellow (c) wrinkled and green (d) wrinkled and yellow 10. The human species has genetic roots in (a) Australia (b) Africa (c) America (d) Indonesia 11. Which of the following is the ancestor of ‘Broccoli’? (a) Cabbage (b) Cauliflower (c) Wild cabbage (d) Kale 12. The process of evolution of a species whereby characteristics which help individual organisms to survive and reproduce are passed on to their offspring and those characteristics which do not help are not passed on is called (a) Artificial selection (b) Speciation (c) Hybridization (d) Natural selection 13. Identify the two organisms which are now extinct and are studied from their fossils. (a) white tiger and sparrow (b) dinosaur and fish (Knightia) (c) ammonite and white tiger (d) trilobite and white tiger 87 Physicsal Science Department 27. What is the difference between genetic drift and change due to natural selection? (a) Genetic drift does not require the presence of variation. (b) Genetic drift never occurs in nature, natural selection does. (c) Genetic drift does not involve competition between members of a species. (d) There is no difference. 28. Which concept was not included in Charles Darwin’s theory of Natural Selection? (a) Struggle for existence (b) Punctuated equilibrium (c) Survival of the fittest (d) Overproduction of offspring. 29. Natural selection is called ‘survival of the fittest’. Which of the following statements best describes an organism? (a) How strong it is compared to other individuals of the same species. (b) How much food and resources it is able to gather for its offspring. (c) The ability to adapt to the environment in the niche it occupies. (d) The number of fertile offspring it has. 30. Human offspring’s sex is determined (а) through father’s sex chromosomes. (b) through mother’s sex chromosomes. (c) by hormones. (d) by enzymes. 90 Physicsal Science Department Answer Key Let’s check your answers. 1. C 16. C 2. A 17. B 3. B 18. B 4. B 19. C 5. C 20. A 6. A 21. B 7. D 22. D 8. A 23. D 9. B 24. C 10. B 25. A 11. C 26. B 12. D 27. C 13. B 28. B 14. A 29. C 15. D 30. A Are you satisfied with your score? If you are not satisfied with the feedback, you may then go back to some points that you may have missed. You will now proceed to the next lesson. 91 Physicsal Science Department UNIT 1. Science and Its Conceptual Foundations Lesson 6. The Human Organism How Much Do You Know? Multiple Choice. 1. Identify the feedback mechanism that maintains your body temperature when your surroundings are very hot. A. The brain sends a message to the skin. The muscles in the skin contract, or shiver, to cool the body. B. The muscles in the skin contract, which sends a message to the brain that you feel hot. The brain sends a message to the skin’s heat receptors. C. Heat receptors in the skin send a message to the brain. The brain sends a response to start sweating, which cools the body. D. The skin starts sweating. The sweat sends a message to the brain, which sends a response to stop sweating. 2. Which of the following statements is TRUE about Introverts? A. Introverts have lower level of arousal than Extraverts for the same stimulus. B. Introverts can become overstimulated. C. Introverts are more easily conditioned to emotional stimuli than those high in Neuroticism. D. Introverts are more impulsive than Extraverts. 3. Which of these are associated with insecurely attached infants in later life? A. less competent C. has less mature friends B. less socially skilled D. A, B and C 4. If a young adult sees stealing as wrong because of the harm it brings to someone, which of Kolberg’ s stages are they displaying? A. punishment and obedience orientation B. good boy- good girl orientation C. legalistic orientation D. social order orientation 5. Bob hasn’t missed a day of work since he started his job three years ago. Every morning he comes in with a smile on his face that remains there until he leaves. He works for a charity and it gives him great satisfaction to know that he’s helping others. He loves his job. Bob is most likely A. a workaholic B. driven by Protestant work ethic C. burned out D. work enthusiast 92 Physicsal Science Department Activate your Prior Knowledge This time relate your prior knowledge to the lesson. Share your thoughts about the statement. 1. Development is lifelong. 2. Development is multidimensional. 3. Development is plastic. 4. Development is contextual. 5. Development involves growth, maintenance and regulation. 95 Physicsal Science Department Acquire New Knowledge This part will present the ideas aligned with the objectives of the lesson. HUMAN IDENTITY In most biological respects, humans are like other living organisms. For instance, they are made up of cells like those of other animals, have much the same chemical composition, have organ systems and physical characteristics like many others, reproduce in a similar way, carry the same kind of genetic information system, and are part of a food web. Fossil and molecular evidence supports the belief that the human species, no less than others, evolved from other organisms. Evidence continues to accumulate and scientists continue to debate dates and lineage, but the broad outlines of the story are generally accepted. Primates—the classification of similar organisms that includes humans, monkeys and apes, and several other kinds of mammals—began to evolve from other mammals less than 100 million years ago. Several humanlike primate species began appearing and branching about 5 million years ago, but all except one became extinct. The line that survived led to the modern human species. Like other complex organisms, people vary in size and shape, skin color, body proportions, body hair, facial features, muscle strength, handedness, and so on. But these differences are minor compared to the internal similarity of all humans, as demonstrated by the fact that people from anywhere in the world can physically mix on the basis of reproduction, blood transfusions, and organ transplants. Humans are indeed a single species. Furthermore, as great as cultural differences between groups of people seem to be, their complex languages, technologies, and arts distinguish them from any other species. Some other species organize themselves socially—mainly by taking on different specialized functions, such as defense, food collection, or reproduction—but they follow relatively fixed patterns that are limited by their genetic inheritance. Humans have a much greater range of social behavior—from playing card games to singing choral music, from mastering multiple languages to formulating laws. One of the most important events in the history of the human species was the turn some 10,000 years ago from hunting and gathering to farming, which made possible rapid increases in population. During that early period of growth, the social inventiveness of the human species began to produce villages and then cities, new economic and political systems, recordkeeping—and organized warfare. Recently, the greater efficiency of agriculture and the control of infectious disease has further accelerated growth of the human population, which is now more than five billion. Just as our species is biological, social, and cultural, so is it technological. Compared with other species, we are nothing special when it comes to speed, agility, strength, stamina, vision, hearing, or the ability to withstand extremes of environmental conditions. A variety of technologies, however, improves our ability to interact with the physical world. In a sense, our inventions have helped us make up for our biological disadvantages. Written records enable us to share and compile great 96 Physicsal Science Department amounts of information. Vehicles allow us to move more rapidly than other animals, to travel in many media (even in space), and to reach remote and inhospitable places. Tools provide us with very delicate control and with prodigious strength and speed. Telescopes, cameras, infrared sensors, microphones, and other instruments extend our visual, auditory, and tactile senses, and increase their sensitivity. Prosthetic devices and chemical and surgical intervention enable people with physical disabilities to function effectively in their environment. HUMAN DEVELOPMENT Human develops from a single cell, formed by the fusion of an egg cell and a sperm cell; each contributes half of the cell's genetic information. Ovaries in females produce ripened egg cells, usually one per menstrual cycle; testes in males produce sperm cells in great numbers. Fertilization of an egg cell by a sperm ordinarily occurs after sperm cells are deposited near an egg cell. But fertilization does not always result, because sperm deposit may take place at the time of the female's menstrual cycle when no egg is present, or one of the partners may be unable to produce viable sex cells. Also, contraceptive measures may be used to incapacitate sperm, block their way to the egg, prevent the release of eggs, or prevent the fertilized egg from implanting successfully. Using artificial means to prevent or facilitate pregnancy raises questions of social norms, ethics, religious beliefs, and even politics. Within a few hours of conception, the fertilized egg divides into two identical cells, each of which soon divides again, and so on, until there are enough to form a small sphere. Within a few days, this sphere embeds itself in the wall of the uterus, where the placenta nourishes the embryo by allowing the transfer of substances between the blood of the mother and that of the developing child. During the first three months of pregnancy, successive generations of cells organize into organs; during the second three months, all organs and body features develop; and during the last three months, further development and growth occur. These patterns of human development are similar to those of other animals with backbones, although the time scale may be very different. The developing embryo may be at risk as a consequence of its own genetic defects, the mother's poor health or inadequate diet during pregnancy, or her use of alcohol, tobacco, and other drugs. If an infant's development is incomplete when birth occurs, because of either premature birth or poor health care, the infant may not survive. After birth, infants may be at risk as a result of injury during birth or infection during or shortly after the event. The death rate of infants, therefore, varies greatly from place to place, depending on the quality of sanitation, hygiene, prenatal nutrition, and medical care. Even for infants who survive, poor conditions before or after birth may lead to lower physical and mental capacities. In normal children, mental development is characterized by the regular appearance of a set of abilities at successive stages. These include an enhancement of memory toward the end of the first month, speech sounds by the first birthday, connected speech by the second birthday, the ability to relate concepts and categories by the sixth birthday, and the ability to detect consistency or inconsistency in arguments by adolescence. The development of these increasingly more complex levels of intellectual competence is a function both of increasing brain maturity and of learning experiences. If appropriate kinds of stimulation are not available when the child is in an especially sensitive stage of development, some 97 Physicsal Science Department