EXAM, 3RD BIOL 164, GENETICS, EVOLUTION & SOCIETY, SPRING 2007 NAME (Last/Family Name First): Signature: Student ID Number: ________________________________ ________________________________ ________________________________
Instructions: Circle the correct answer, or circle the letter corresponding to the correct answer, or write in the correct answer, as appropriate. In all cases, write legibly; answers that I cannot read will be considered incorrect. All questions are of equal point value. Good luck! ~~~~~~~~~~~~~~~~~~~~~~~
1. The "irreducible complexity" argument of "Intelligent Design" (ID): a. Assumes only small, gradual morphological changes in evolution b. Assumes structures maintain essentially the same function throughout much of their evolution c. Assumes that the investigator can imagine all possible paths of evolutionary change and all possible functions for a structure d. All of the above
2. Does the Enlightenment approach to knowledge assume that we start scientific inquiry knowing all possible mechanisms? Yes OR No
3. When statistics suggest that a particular event is exceedingly unlikely: a. It is impossible that it occurred b. It must have occurred. c. We cannot decide between a & b unless we have an alternative explanation which is more or less likely.
4. When (approx.) did humans last share an ancestor with chimpanzees and bonobos? a. 5 MYR b. 10 MYR c. 20 MYR d. 35 MYR
5. Place the letter of the appropriate group on the primate phylogeny: Humans ____c____ ____b____ ____d____ ____a____
a. b. c. d.
Hylobates (gibbons) Gorilla (gorillas) Pan (chimps) Pongo (orangutan)
6. The evidence for bipedality in australopithecines versus chimpanzees does NOT include: a. foramen magnum points down/spinal cord enters from bottom of skull b. "S-curvature" of spine c. arms shorter than legs d. grasping digits
7. Which member of the genus Homo was the first to have speech, use fire, and cross ocean barriers? a. H. afarensis b. H. habilis c. H. erectus d. H. sapiens
8. The main difference between what is typically called "natural" versus "artificial" selection is that natural selection usually prevents 1-10% of the population from breeding, while artificial selection (e.g., on crops) usually prevents 90-99% of the population from breeding. True OR False (Circle one.)
9. Far less than half or more of all corn, soy, and cotton grown in the U.S. is genetically modified. True OR False (Circle one.)
10. Which of the following is NOT a benefit of genetically modified (GM) crops: a. For crops like the mustard family, which readily hybridize with wild relatives, escaped genes could create superweeds immune to insect predation b. GM corn and cotton containing Bt toxin reduces the need for broadcast spraying of insectide which can kill nontarget species (e.g., insects, birds, etc.) c. Resistance to chemicals which are sprayed and permeate the whole environment evolves much faster than resistance to GM crops with Bt toxin, which only poisons those organisms which feed on the crop d. Roundup is a relatively benign pesticide compared to DDT, etc.
11. Roughly how many generations do crops go through for every human generation? a. 2 b. 20 c. 200 d. 2,000
12. According to the World Health Organization (WHO), roughly what proportion of human deaths each year are caused by disease organisms ("communicable diseases", as opposed to non-communicable diseases, like hardening of the arteries): a. None b. One-third c. Two-thirds d. All
13. The Ebola virus is clearly not a disease that humans could normally support as hosts. Ebola needs another species to act as a: a. vector b. reservoir c. population d. conjugator
14. Bubonic plague (Yersinia pestis) is a bacterium that killed 1/3 of Europe during the Middle Ages. Plague infects rodents (e.g., Rattus spp.) often without killing them. Rats, of course, have fleas (like Xenopsylla cheopis, the oriental rat flea), which will also bite humans and can thereby infect them with plague. In the mid-1300's, the cities of Europe were at their largest sizes and highest population densities in history up to that point. Europe was ripe for an explosion of a disease in humans because (circle all that apply): a. Large host population b. Densely spaced host population c. Reservoir for disease d. Vector for disease
15. Highly virulent diseases are selected for within a host because they produce fewer spores (particles for infecting the next host); they are selected against by hosts being very abundant and close together. True OR False (Circle one.)
16. The first asexual reproduction in sharks was just recorded in an aquarium in Detroit. Reproducing asexually has a huge evolutionary advantage in the short term, in that each offspring has your whole genome, instead of just half, as in sexual reproduction. The reasons that sexual reproduction and recombination maintained, are despite this disadvantage, include that diseases evolve much faster than their hosts. True OR False (Circle one.)
17. Match the major decomposer group with the major group of which it is the most important decomposer: Bacteria Animals Fungi Plants
18. What is the name of the component of the bacterial cell wall that penicillin and related drugs prevent bacteria from making properly? a. phosphoglycan b. peptidoglycan c. aminoglycan d. carboglycan
19. The exchange of antibiotic resistance (ABR) genes among different species of bacteria can occur very rapidly when the ABR genes are carried on: a. cell membrane b. ribosomes c. chromosomes d. plasmids
20. Potential benefits to be derived from the preservation of biological diversity include: the discovery of new drugs (esp. antibiotics); the domestication of new crops; genetic traits in wild relatives of crops that are useful (drought resistance, etc.). True OR False (Circle one.)
21. Costanza et al. (1997) provided a minimal estimate of the dollar value of services that are provided for free by natural ecosystems. Was their estimate more or less than total global GNP? More OR Less
22. Historically, fire has been a normal, natural disturbance in prairies and pine forests. True OR False.
23. What makes the preservation of tropical forests a high priority? a. they have fewer species/biodiversity than other areas b. they are being cut down at low rates c. they are in countries with very low future human population growth d. all of the above e. none of the above
24. What is the general source of ill effects on the phenotype of inbred individuals? a. Deleterious recessive alleles become homozygous b. Potentially useful recessive alleles become heterozygous c. Potentially useful alleles have higher mutation rates d. They have entered into the extinction vortex
25. What undesirable phenomenon does genetic drift cause? a. inbreeding b. loss of alleles c. demographic flux d. polygyny
26. The concept of genotype-environment interaction (described briefly in lecture, but sadly ignored by authors of text) means, in essence, that the relative performance of different genotypes remains the same across all different environments. True OR False
27. Monozygotic ("identical"; MZ) twins have the same genotypes, while dizygotic ("fraternal"; DZ) twins share half their genes on average. In principle, then, the phenotypic correlation or concordance between monozygotic twins should always be twice that of dizygotic twins. When the similarity among MZ twins is more than twice that of DZ twins, where has the `missing' similarity gone? (E.g., when the MZ concordance is 80% and the DZ correlation is 20% instead of 40%.) a. the trait is entirely under genetic control b. the trait is partly under environmental control c. shared environment creates additional phenotypic similarity d. epistasis or genotype-environment interactions are occurring
28. Single locus (Mendelian) disorders like cystic fibrosis and sickle-cell anemia tend to be rare, recessive, and deleterious as homozygotes. Quantitative disorders like alcoholism and schizophrenia tend to be much more common and have substantial False environmental components to the phenotype. True OR
29. In the U.S., we currently have some of the most astounding inequities in economic wealth anywhere in the world. Some argue that the promise or possibility of being able to attain the status of being ludicrously wealthy is partly responsible for our economy's vigor and creativity. (Whether or not this is true is a matter outside of biology, but assume it is so for the purposes of this question.) Professor Rosenberg suggested in the Human Genome Project symposium that the ability to genetically engineer children would entirely eliminate the ability of the less wealthy to achieve great wealth, and create a caste system in which one's economic status could not change. This would occur because the wealthy would purchase "wealthy" alleles for their offspring, which would enhance their ability to attain wealth. Assume that the ability to become wealthier is like most other more or less continuously distributed, probabilistic behavioral traits controlled by many loci, with a heritability in the usual range of 0.3 to 0.7. Is Professor Rosenberg correct that having a certain set of genes guarantees that one's economic status cannot be changed? Yes No
30. The Human Genome Project is an effort to sequence the entire human genome, with the idea that this information will help us understand our biology better. Match the three major tasks with their projected completions: Identify all proteins in genome Sequence entire human genome Understanding all phenotypes produced by all proteins Already done Next few decades Many decades, if ever
Have a great summer! (Kindly fill out CTEC's. Grades should be posted next week. - JSW)