BIOLOGY TODAY: AN ISSUES APPROACH PROTOTYPE SYLLABUS FOR A TWO-SEMESTER COURSE (revised Dec., 2003) == FIRST SEMESTER == Week 1. Introduction to science and its context. (Chapter 1.) 1. Introduction to the course. Introduction to science and its methods; distinctions (if any) between science and nonscience. 2. Biology and its relation to other sciences. Characteristics of Living Systems. 3. Science in theory and science in practice: science and scientists in a social context. History of science as an organized community of scientists. DISCUSSION QUESTIONS: What is science? What are its boundaries? How does science differ from other disciplines? Does science have one method or many? Can science be made value-free? Is science exclusively a European invention? Week 2. Ethics and social decision making. 1. Ethical systems. Ethical and unethical behavior within the scientific community. 2. Ethics and social decision-making in general. Balancing conflicting rights and conflicting ethical systems. 3. Animal rights as a case in point: ways in which "rights" for animals are justified. Balancing the rights of different species. DISCUSSION QUESTIONS: On what basis do we say that people have certain rights? What rights do animals have, and why do we recognize certain rights and not others? What happens when the rights of different species conflict? Week 3. Principles of genetics. Gene structure. (Chapter 2.) 1. Mendel's discovery of simple inheritance patterns; dominant and recessive traits; particulate inheritance and segregation; development of the concept of the gene. 2. Mitosis and chromosomes; meiosis and independent assortment; linkage and crossing over. Chromosomes and genes; sex determination; unusual chromosomal types. 3. DNA and the basis of inherited traits. Structure of DNA and RNA; DNA replication. DISCUSSION QUESTIONS: What evidence led Mendel to assume that inheritance was particular? How does meiosis differ from mitosis? What is the are structure of DNA? How are genes related to chromosomes, and how was this relation discovered? Week 4. Human genetics. (Chapter 3.) 1. Metabolic disorders and single-gene inheritance in humans. 2. Transcription from DNA to RNA; translation from RNA to proteins; basics of gene regulation (more detail in ch. 12). 3. Hereditary risks in humans: identifying traits and risks; pedigree analysis; genetic markers. DISCUSSION QUESTIONS: Does "information" flow only in one direction from DNA to RNA to protein? Is DNA the Master Molecule? Is genetics value-laden? Are there cultural biases in its terminology? What are the differences between a gene and a trait? What are the differences between a trait and a risk? Week 5. Human genetics, continued. (Chapter 3 plus start of Ch. 4.) 1. Possible actions once a gene or its trait is identified: diagnostic methods, medical treatment of individuals, eugenics proposals and their possible ramifications. 2. Alternatives to eugenics: euphenics, euthenics, eupsychics; intro. to genetic engineering. 3. Recombinant DNA technology: restriction enzymes, vectors, plasmids, cloning, methods needed to select recombinants. DISCUSSION QUESTIONS: What ethical issues are raised once genetic traits are identified? Should individual genotypes and phenotypes be altered? Should we try to alter the human gene pool? Is genetic engineering cost-effective? Is it ethical? Week 6. Genetic engineering and genomics. (Chapter 4.) 1. Recombinant DNA applied: bacterial growth of commercial gene products; genetic engineering as a form of euthenics. Forensic uses of DNA. 2. The Human Genome Project. 3. Genomics and proteomics. DISCUSSION QUESTIONS: How is DNA technology aurrently being used? Are there any ethical problems, and how can be they best be addressed? Are new safeguards needed to deal with DNA technologies? What have we learned from the Human Genome Project? What will we continue to learn? What new tools do we need? Week 7. Evolutionary processes. (Chapter 5.) 1. The Darwinian paradigm. The dynamic earth (geologic change, fossils). Adaptation; natural selection; patterns of evolution; branching descent with modification; homologous structures. 2. Creationist objections to evolution; scientific responses. Varieties of creationism, including "intelligent design". Evidence for and against creationist claims. 3. Species and modern evolutionary theory. Forces of evolution; speciation and isolating mechanisms; biogeography. DISCUSSION QUESTIONS: What observations did Darwin try to explain? Did his theories explain them adequately? What objections have creationists raised? Are creationist objections made within the boundaries of science? What constitutes evidence for or aginst creationist claims? Why are species central to modern evolutionary theory? How do new species form? MIDTERM EXAMINATION (suggested placement, for schedules that have a single major midterm plus a final). Week 8. Classifying nature's diversity. (Chapter 6.) 1. Procaryotic & eucaryotic cells; animal and plant cells. 2. Classification in general (taxonomic theory). Six-kingdom classification of organisms. Procaryotic kingdoms. 3. Kingdoms Protista, Mycota, and Plantae. DISCUSSION QUESTIONS: What evidence supports our present theory concerning the origin of life? How are organisms currently classified, and why? How are classification schemes developed? Week 9. Classifying diversity (continued). 1. Vascular plants. Simple animals. 2. Kingdom Animalia and its evolution. 3. Human evolution. Cultural versus biological evolution. Evidence of continuing evolution today. DISCUSSION QUESTIONS: What major evolutionary advances occurred in the evolution of protists, fungi, and plants? What major events occurred during the evolution of animals? What evidence do we have that humans evolved, or that evolution is still occurring? Week 10. Human populations and their variation. (Chapter 7.) 1. Concepts of population and race: their history, sociology, and relation to political power and biology. Objective use of scientific concepts versus their use as tools of power. 2. The genetic basis of human variation. Concepts of population genetics, including gene pools. Genetic variation within populations; variation between populations. Genetic equilibrium and the Hardy-Weinberg principle. Genetic drift and other forces of evolutionary change. 3. Adaptive value of many human variations: disease as an agent of selection; malaria as a disease caused by a parasite; parasite life cycle; traits that protect against malaria; traits related to vitamin D; interaction of cultural and biological evolution. DISCUSSION QUESTIONS: What are races? Do races exist, and how do we define them if they do? Is it possible to recognize races without being a racist? How much of human variation is due to adaptive forces like selection, and how much to nonadaptive forces such as genetic drift and founder effects? Week 11. Sociobiology. (Chapter 8.) 1. Sociobiology and its paradigm. Communication as a form of social behavior. Social organization is adaptive. Methods of studying social behavior; methods of distinguishing instinct from learning, or genetic from environmental influences. 2. Evolution of altruism: alternative explanations, including group selection, kin selection, and reciprocal altruism. Evolution of eusociality: haplodiploidy and kin selection. 3. Primate and human sociobiology. Extrapolation from other species and its limitations. Use of sociobiological methods to study human behaviors (like alcoholism) that don't have exact parallels among other species. DISCUSSION QUESTIONS: What are the assumptions that sociobiologists commonly make? Which assumptions are necessary (in the sense that you cannot study sociobiology without making them)? How are these assumptions justified? Why do males and females follow different reproductive strategies in many species? How do these reproductive strategies complement one another? In what ways are primates different, or are they much the same as other species? Are humans unique? How far can the findings of sociobiology be extrapolated from other species to humans? Are humans fundamentally different, and, if so, why? What parallels exist among other species to behaviors like alcoholism or homosexuality? WE RECOMMEND FILMS, as local availability permits. We recommend devoting at least one class period to films if at all possible. Week 12. Population growth and its control. (Chapter 9.) 1. Population size and the factors that regulate it. Demography and population ecology through exponential growth equations and doubling time in various actual populations. 2. Demography (continued): resource use, logistic growth, carrying capacity, r- and K-selection; controls on population growth. Introduction to reproductive biology. 3. Human reproductive anatomy and physiology. Hormones and reproductive cycles. Birth control methods. DISCUSSION QUESTIONS: Do we know how fast human populations are growing? Can we reduce the rate of human population growth? What are some social implications of urging population control on other populations? Why are different birth control methods appropriate to different people or to different societies? Week 13. Nutrition and health. (Chapter 10.) 1. The processes of digestion. Metabolism and energy trans- formation. Stepwise processing of each major nutrient type (carbohydrates, lipids, proteins). 2. Nutrients that the body needs. Molecular structures and characteristics of carbohydrates, lipids, proteins, vitamins, and minerals. 3. The process of absorption. Cell membranes; diffusion and active transport of materials across cell membranes. The circulatory system and cardiovascular health. DISCUSSION QUESTIONS: What is each nutrient needed for? How does the body process each? Why are the solubility characteristics of nutrient molecules important? What can we do to maintain cardiovascular health? Week 14. Nutrition and health (continued). 1. Cellular metabolism: oxidation-reduction reactions and ATP production; glycolysis; Krebs cycle. 2. Electron transport and the cytochrome system; processing of different nutrients. Eating disorders: anorexia, bulimia, obesity. 3. Nutritional inadequacies: fad diets; vitamins and possible overdoses; variations in nutrition around the world; micronutrient malnutrition, protein deficiency, starvation, world hunger, effects of poverty in both poor and wealthy countries. DISCUSSION QUESTIONS: What happens when there is an inadequate supply of nutrients in general, or of particular nutrients? What happens when the supply is excessive? Which problems are of greatest concern in the population around you? Which problems are of greatest concern in other populations? END OF FIRST SEMESTER ------------------------- BIOLOGY TODAY: AN ISSUES APPROACH TWO-SEMESTER COURSE SYLLABUS, continued == SECOND SEMESTER == Week 15. Plants and crops. (Chapter 11.) 1. Plant pigments and photosynthesis. Energy and metabolism. Heterotrophs and autotrophs. Producers, consumers, and decomposers. 2. Plant products other than carbohydrates. Nitrogen and its compounds in plants. Plant adaptations to obtain nitrogen. Carnivorous plants. Steps in the nitrogen cycle. 2. Structure of vascular plants. DISCUSSION QUESTIONS: How can biological systems be used to help solve environmental problems? What factors limit the effectiveness of bioremediation? In chapter 10 we studied the Krebs cycle and other processes of cell metabolism. What do these processes have in common with photosynthesis? What differences exist among these processes? What are some of the many ways in which plants and their products may be considered useful? What sorts of value judgements are embedded in terms like "useful"? What impiortant life functions are carried out by each part of a vascular plant? How do vascular plants differ from nonvascular plants? What special adaptations to flowering plants exhibit? Week 16. Plants and crops (continued). 1. Communities, ecosystems and the biosphere. Energy flow through ecosystems: food chains and food webs. Nitrogen cycle in terms of niches in the community and symbiosis. 2. Improving crop yields. Ecological succession in natural and human-designed ecosystems. Fertilizers, soil conservation and irrigation; renewable and nonrenewable resources; trophic pyramids and biomagnification. 3. Pest control methods. Genetic engineering in plants. DISCUSSION QUESTIONS: How can crop yields be increased? Will methods that work in some places always work in other places? What limitations exist to world-wide adoption of agricultural practices that increase crop yields? Why might a pesticide like DDT be used in some places and banned in other places? What are some long-term consequences of pesticide use? What are some alternatives? Should genetic engineering be used to improve plant species? What risks do we need to test for? Week 17. Stem cells and cell division. (Chapter 12). 1. Cell division and its control. Evolution of multicellularity; slime mold life cycle; division of labor among cells; cell differentiation and tissue formation. 2. Gene expression and differentiation. Control of cell division. Stem cells and their possible uses and risks. 3. Interaction of genotype and environment. Cellular detection of environmental stimuli; control of cell division and differentiation by genes and by environmental stimuli. DISCUSSION QUESTIONS: What is the relation between cell division and cancer? between cell division and differentiation? between differentiation and gene expression? How can genes and environmental stimuli influence the cell cycle? Week 18. Cancer and cancer therapy. (Chapter 12, continued) 1. How cancers arise: Possible mechanisms and known risk factors. 2. Oncogenes and proto-oncogenes. Mutagenesis and carcinogenesis. 3. Cancer prevention and treatment: Risk factors. Smoking, alcohol, nutrition. Testing of mutagens: the Ames test. DISCUSSION QUESTIONS: What evidence is adequate to implicate something as a risk factor? as a cause of cancer? How do we evaluate disputed claims? Bruce Ames says that we are surrounded by thousands of natural as well as artificial carcinogens, but that we should not be alarmed over this fact-- what does he mean by this? Week 19. The Nervous System. (Chapter 13.) 1. The brain and its parts. Circulation to the brain; blood-brain barrier. Nerve cells (neurons) and neuroglia. 2. Nerve impulses. Sense organs. 3. Neurotransmitters and their malfunctions. Brain diseases related to neurotransmitter malfunctions. DISCUSSION QUESTIONS: What evidence do we have that certain parts of the brain govern certain activities? How are nerve impulses investigated? What brain malfunctions are related to neurotransmitter activity? Can we distinguish between neurological and psychiatric disorders? How might we investigate why depression occurs more often among women than among men? Week 20. Nervous system: the brain. 1. Evidence for neurotransmitter malfunction in certain brain diseases. Therapy (including drugs) for these conditions. 2. Circadian rhythms and sleep; disturbed rhythms. 3. Learning and memory. DISCUSSION QUESTIONS: What evidence allows us to name a particular neurotransmitter as responsible for a particular type of malfunction? It is ethical to give drugs that alter personality? What rights do Alzheimer's patients have in specifying how and when their lives should be terminated? Brain wave patterns change in people who are sleep-deprived; what does this tell us about brain activity during sleep? Week 21. Drug use & abuse. (Chapter 14.) 1. Drugs in general. Drug uptake by various routes: via gas exchange in the lungs, via absorption from the digestive tract, and via blood circulation in the placenta. 2. The excretory system and its role in drug elimination. 3. Drug interactions. DISCUSSION QUESTIONS: What are some reasons why the same drug dose might affect different individuals differently? By what routes do drugs enter the body? What biological processes are involved? How are drugs eliminated from the body? What are some of the mechanisms by which drugs might interact? Week 22. Psychoactive drugs and their activity. (Chapter 14, continued). 1. Receptors and cellular mechanisms of drug action. Particular psychoactive drugs and their symptoms. 2. Drug abuse and addiction: effects on individuals. 3. Drug abuse and addiction: effects on development; effects on populations. DISCUSSION QUESTIONS: What causes certain drugs to be addictive? What evidence is needed to conclude that a particular drug is addictive? Pick a drug for discussion that is currently illegal or legally regulated; what evidence would cause you to change your mind one way or the other on the question of tightening or loosening restrictions on the use of this drug? MIDTERM EXAMINATION (suggested placement, for courses having a single major midterm exam plus a final) Week 23. Stress and the mind-body connection. (Chapter 15.) 1. The mind-body connection. The immune system as a sense organ. Feedback loops. 2. The neuroendocrine system. Hormones. Autonomic nervous system. The stress reaction. 3. Stress and immunity. Mechanisms and evidence. Individual variation. Theories of health and disease. DISCUSSION QUESTIONS: What relationship does the "mind" bear to the neuroendocrine and immune systems? How can this relationship be studied? What statements about the mind are falsifiable? Week 24. HIV and AIDS. (Chapter 16.) 1. Discovery of AIDS as a disease. Evidence to connect many diverse symptoms; evidence of a viral cause. Discovery of HIV; evidence that it causes AIDS. 2. Viruses and their life cycles. How HIV infection causes AIDS. 3. Testing for HIV and AIDS. Ethical and legal issues involved in testing. DISCUSSION QUESTIONS: How good is the evidence that HIV causes AIDS? Why are some people unconvinced? Why is it so difficult to study HIV infection? How is HIV different from most other viruses? How is AIDS different from most other diseases? Week 25. AIDS (continued); New Infectious Threats (Chapter 17). 1. Avoiding HIV and AIDS. Reducing the incidence of HIV infection in populations. 2. New infectious threats: characteristics of pathogens; evolution of virulence; factors favoring the spread of pathogens; bioterrorism. Sexually transmitted diseases and their increased spread. New transmission risks for foodborne diseases, for water- borne diseases, and for vector-borne diseases. Bacterial diseases: plague, tuberculosis, botulism, etc. Viral diseases: herpes, papilloma, West Nile, etc. Other diseases: giardiasis, leishmaniasis, etc. 3. Social issues raised by AIDS and other infectious diseases. Difficulties encountered in changing risk behaviors. Legal and ethical aspects of various public health proposals. DISCUSSION QUESTIONS: What technical and ethical limitations make it difficult to study the effectiveness of drugs that might help prevent AIDS? Are some people naturally more susceptible or more resistant to AIDS? What are the most effective ways to reduce the incidence of AIDS, and what objections might be raised to these measures? What new and changing factors are responsible for the spreading of new disease threats? What new diseases are spreading, and how? What old diseases are spreading once again, and why? How can we control these various new threats? Week 26. Biodiversity, extinction, threatened habitats. (Chapter 18.) 1. Biodiversity: its measurement and importance. Niches. Interaction and interdependence of species. 2. Extinction in the past. Extinction and threatened habitats today. 3. Communities, ecosystems, and biomes. Biogeography. Conservation. DISCUSSION QUESTIONS: What is biodiversity, and how is it threatened? How (and in what circumstances) has extinction occurred in past geologic ages? How would you evaluate conflicting theories regarding past extinctions? Are the extinctions occurring today similar to or different from extinctions in the past? Week 27. Biodiversity (continued). Protecting the Biosphere (Chapter 19.) 1. Endangered habitats. How can habitats and biodiversity be protected? Environmental ethics; social issues raised by conservation attempts. 2. Origin of life. Simplest organisms. Anaerobic and aerobic life forms. 3. The atmosphere and how it has changed. How life interacts with the atmosphere. Chlorofluorocarbons and the ozone layer. DISCUSSION QUESTIONS: Does habitat have intrinsic value, or only instrumental value? Will it be easy or difficult to get both wealthy and poor people to help protect biodiversity? Is there any way around the problem of NIMBY ("not in my back yard") thinking? Week 28. Protecting the Biosphere (continued). 1. Local and regional pollution; acid rain and similar threats. 2. Possible solutions to some environmental problems. Bioremediation. Water treatment. 3. Carbon dioxide and global warming. DISCUSSION QUESTIONS: How did life on Earth originate? How do we know that Earth's atmosphere has changed? What is the evidence that life was responsible for a major portion of this change? How can acid rain in one place be controlled if its causes are someplace else (e.g., in a different country)? Why is the ozone layer important? What causes damage to this layer, and how? Is there a way to repair the damage to the ozone layer? What causes global warming? How can global warming be mitigated? FINAL EXAMINATION. MISCELLANEOUS NOTES AND HELPFUL HINTS FOR INSTRUCTORS: 1. We assume that the above syllabus will need to be locally modified to adjust for differing semester lengths, numbers of meetings per week, and so forth. 2. If possible, we recommend weekly discussion sessions in addition to lectures. There are several possible ways of doing this. For example, students could be arranged into study groups and assigned in rotation the task of presenting material, after which all students in each group ask questions and check on each other's understanding. Instructor-led discussions are another possibility. In any event, we recommend that these discussion sections be small groups. Some instructors may even run the whole course through these discussions, without traditional lectures at all. Many additional thought questions for discussion may be found at the end of each section within each chapter. 3. The discussion questions listed on the preceding pages, as well as the Thought Questions in each section, may also be used as written critical thinking assignments. One or more questions each week may be assigned as the subject for short position papers or similar short writing assignments. The ensuing discussions often flow more smoothly if students have individually researched and/or thought about these or similar topics. 4. You may ask each student to keep a notebook or folder of clippings from newspapers and popular magazines related to course topics (or to science in general). It may be profitable to discuss some of these articles publicly in class near the end of the semester. 5. The scheduled frequency of long exams and shorter quizzes varies greatly from place to place. We fully expect individual instructors to adjust the above schedule to suit their own needs. 6. Although it is possible to teach this course without a lab, we recommend that a lab be included. We welcome hearing about any particularly successful laboratory experiences. PERMISSION IS HEREBY GRANTED to instructors who have adopted the book BIOLOGY TODAY for classroom use to download, modify, and use these notes as needed to aid them in in their teaching. Students of such instructors may likewise use and modify these notes as study aids.