BIOLOGY 102 - HUMANKIND IN THE BIOTIC WORLD DR. ELIZABETH CANTWELL - EXAM 3, FORM A ? SPRING 2010 Instructions: In all cases, choose the option that BEST answers the question or completes the statement. Chapter 15 ? Tracing Evolutionary History 1. How is the merging of continents to form Pangaea believed to have altered Earth's environments at the end of the Paleozoic era? A. It reduced competition among terrestrial organisms by producing new geographic barriers. B. It eliminated all eukaryotes, allowing evolution to start anew. C. It reduced the number of coastal and shallow-sea environments, leading to the extinction of many marine species. ANSWER: C 2. The first step during the origination of life on Earth was probably formation of? A. Oxygen gas C. Carbon dioxide gas B. Simple organic molecules D. Protobionts ANSWER: B 3. The Cambrian explosion resulted in the evolution of more than 17,000 species of trilobites. The number of trilobite fossils found in modern times suggest that trilobites were very abundant, perhaps the rulers of the seas. Today, no living descendants of this group exist. What happened? A. In order to disappear from the planet entirely, trilobites must have undergone the process of adaptive radiation. B. It is unlikely that trilobites could have survived the increase in atmospheric oxygen once the process of photosynthesis had evolved. C. Since trilobites evolved before the first mass extinction, it is possible that one or more extinctions wiped out the entire group. ANSWER: C 4. Which of the following properly summarizes the findings and hypotheses of Pasteur, Oparin and Haldane? A. Life today does not arise from nonliving matter, but in the conditions of early Earth, it could have occurred. B. Cells come from cells in any atmosphere. C. Complex organisms can generate spontaneously from nonliving matter if the conditions encourage it. ANSWER: A 5. A bee species obtains nectar from trumpet flowers. When disease wipes out many competing plant species, the trumpet flower radiates, and five new species of flower arise. What is likely to occur with the bees? A. Since speciation will certainly to result in the extinction of the original trumpet flower species, the bees will also go extinct. B. The bees may also radiate in response to the availability of new food sources. C. Nothing is likely to occur with the bees. ANSWER: B 6. Scientists have discovered that Arctic Cod and Antarctic Icefish both produce ?antifreeze proteins? that help them survive in their cold environments. The most recent common ancestor of these fishes did not produce these proteins. The genes involved and the antifreeze proteins themselves are significantly different in the two species. Which of the following statements is likely true? A. The genes that encode these antifreeze proteins were once homologous, but were mutated in one population and are now analogous because they are different. B. Horizontal gene transfer allowed these populations to share genetic information. The proteins are homologous. C. These populations inhabit similar environments. They developed similar survival adaptations by convergent evolution. The proteins are analogous. D. These populations inhabit similar environments. They developed similar survival adaptations by convergent evolution. The proteins are homologous. ANSWER: C 7. Which of the following adjectives best describes the first life on Earth, based upon the current accepted hypothesis? A. Photosynthetic C. Simple B. Aerobic D. Eukaryotic ANSWER: C 8. The Lycopodium plant evolved before the breakup of Pangaea. Sequoia trees evolved after Pangaea split into separate land masses. Which plant would you expect to have the widest distribution across the modern continents? A. Lycopodium C. Both should be equally distributed B. Sequoia trees D. Both should be extinct ANSWER: A 9. Continental drift has played a role in which of the following? A. Habitat change C. Promoting speciation B. Extinctions D. All of the above ANSWER: D 10. Refer to the figure representing a cladistic analysis of plants. Which of the groups shown posess the shared ancestral character, chloroplasts? A. 5 only B. 1 only C. 1 and 2 D. 2 ? 5 E. 1 ? 5 ANSWER: E 11-12. Match the period/era with the description below. A. Cenozoic C. Precambrian B. Paleozoic D. Mesozoic 11. This era saw the origination of plants, insects and reptiles, as well as the radiation of plants, fish, amphibians and reptiles. ANSWER: B 12. This era saw a massive radiation of mammals, birds, insects and angiosperms, as well as the origination of primates and humans. ANSWER: A 13. In which of the following statements was parsimony applied? A. My daughter?s favorite blanket is missing. It probably involves some elaborate plot involving our dog, the cats and a bottle of mustard. B. Crabs and lobsters both have claws. Their most recent common ancestor has claws. This is clearly a result of convergent evolution. C. Police arrive at a crime scene. A man is dead and his wife is covered in his blood. They suspect she may have been the killer. ANSWER: C 14. Which of the following statements regarding emergence is FALSE? A. Emergence describes the way complex systems and patterns arise out of multiple relatively simple interactions. B. Examples of emergence are not easy to find in Biology, but are common in Chemistry. C. Origins investigators believe that, given the chemical makeup of early Earth, the emergence of life was inevitable. ANSWER: B 15. Over a span of several thousand years, a number of species show adaptations to climate change: drier, warmer conditions select for succulent vegetation and deep taproots in plants, burrowing in mammals and amphibians, and other similar adaptive changes. What will happen if the climate shifts and becomes progressively wetter and cooler? A. Ongoing processes of adaptation will continue because the course of a trend cannot change with the environment. B. The current trend toward hardiness in dry conditions is consistent with evolution's overall goal of making organisms better-prepared to deal with stress, so it will continue. C. Current adaptive trends will continue but organisms will now also have to mutate, adding on adaptations to deal with cool, wet conditions. D. Different adaptive trends will be favored in the new climatic environment. ANSWER: D 16. Which of the following statements regarding the atmospheres of Earth is FALSE? A. The first atmosphere of Earth was 100% nitrogen, and encouraged the process of planetary cooling. B. Our understanding of the second atmosphere is based upon modern volcanic venting. C. The complexity of life currently on Earth would be impossible without atmospheric oxygen. ANSWER: A 17. Which of the following statements regarding systems of arrangement is FALSE? A. While the three domains of life diverged fairly early in evolutionary history, some have suggested that genetic material has been transferred from domain to domain. B. Since they are both prokaryotes, it makes sense that Archaea are more closely related to Bacteria than they are to Eukaryotes. C. Although the Domain system is currently favored, it is constantly being reevaluated as new hypotheses are presented. ANSWER: B 18. Which of the following environments is thought to have promoted the formation of macromolecules from smaller organic monomers on a lifeless Earth? A. Quiet saltwater bodies B. Freshwater swamps and marshes C. Deep-sea hydrothermal vents D. The vacuum of outer space E. Hot sand, clay, or rock along the seashore ANSWER: E 19. Which of the following is an example of an exaptation? A. Clownfishes have evolved the ability to bleach themselves of color at night so that they can hide within an anemone?s tentacles. B. Many insects are capable of powered flight. In these species, wings originally evolved to provide insulation, but then became adapted for flight. C. Lions are color blind. As a result of natural selection, zebras evolved black and white stripes, which allowed them to blend into their grassy habitat. . ANSWER: B 20. Which of the following events would change the classification of a protobiont, which is not alive, to a prokaryote, which is? A. The ability to carry out photosynthesis B. The formation of a lipid membrane C. The formation of genes made of DNA D. The ability to replicate genes and reproduce ANSWER: D 21. The duplication of homeotic genes is believed to have led to __________ over the course of evolutionary history. A. Extinction D. Analogy B. Increased complexity E. Gradual refinement C. Exaptation ANSWER: B 22. You want to determine the evolutionary relatedness of specific species of bee, bacteria, fish, fern and chimpanzee. Which of the following sets of shared derived characters would be most appropriate for comparison? A. Life cycle characteristics C. Presence or absence of chloroplasts B. Molecular sequences D. Morphological traits ANSWER: B 23. Based on what we discussed, which of the following best describes the likely role of oxygen gas in the early stages of life's origin on Earth? A. Since oxygen disrupts organic molecules, its absence promoted the formation and stability of complex organic molecules on the early Earth. B. Oxygen promoted the formation of complex organic molecules through physical processes. C. Abundant atmospheric oxygen created an ozone layer, which blocked out ultraviolet light and thereby protected the earliest life forms. ANSWER: A 24. A chimpanzee is born with hands that are backwards (palms up, thumbs face inward instead of outward). Without doing any genetic analysis, what could you reasonably hypothesize? A. Mutation changed the meaning of a developmental gene. B. Mutation changed the expression of a developmental gene. C. Mutation changed either the meaning or expression of a developmental gene. ANSWER: C 25. Refer to the figure. According to this cladogram, which statement regarding the phylogeny of whales is FALSE? A. Humpback is more closely related to Blue than to Gray B. Bryde?s is more closely related to Sei than to Pygmy Bryde?s C. Bryde?s is more closely related to Pygmy Bryde?s than to Fin D. The Minke ancestor diverged early in the evolution of the whale lineage ANSWER: A 26. Which of the following statements regarding protobionts is FALSE? A. A protobiont is a collection of abiotically produced organic molecules within a lipid membrane. B. The internal environment of a successful protobiont would have been similar to its external environment. C. Those early protobionts that were more successful in their environments would have been favored by natural selection. ANSWER: B 27. Which of the following options lists major originations in the history of life on Earth in the proper order, from earliest to most recent? 1. Animals 2. Photosynthesis 3. Land plants 4. Prokaryotes 5. Humans 6. Eukaryotes A. 2, 4, 6, 1, 3, 5 D. 4, 2, 6, 3, 1, 5 B. 2, 4, 6, 1, 5, 3 E. 6, 2, 4, 3, 1, 5 C. 4, 2, 6, 1, 3, 5 ANSWER: C 28. The ancestors of whales were tetrapod animals that lived and moved on land. As their food supply became scarce, they went to the water to find food, using their limbs and tails to move in the water. As the lineage progressed, the whale forelimbs developed into flippers and the hindlimbs grew shorter, as the tail became larger and more muscular. Eventually, species similar to the whales, dolphins and porpoises we know today swam in the water. This is an example of? A. Gradual refinement B. Gradual adaptation ANSWER: A Chapter 16 ? The Origin and Evolution of Microbial Life: Prokaryotes and Protists 29. What is it that the two competing hypotheses regarding eukaryotic and nuclear origin cannot agree upon? A. The origin of the endomembrane system B. The origin of the nucleus and nuclear envelope C. The source of ancestral eukaryotic DNA D. A and B E. A ? C ANSWER: B 30. This structure allows a prokaryote to move in a fluid or semi-fluid environment by producing a corkscrew-like motion. A. Flagella C. Capsule B. Pili D. Cell wall ANSWER: A 31. Heliobacteria use photosynthesis to convert light energy to chemical energy. They require organic sources of carbon such as carbohydrates and fatty acids to survive. A. Photoautotroph C. Photoheterotroph B. Chemoautotroph D. Chemoheterotroph ANSWER: C 32. Nitrosomonas europaea is a bacterial species that can degrade a variety of benzene-based environmental pollutants. N. europaea is found in soil, sewage, freshwater and on building surfaces. It is rod-shaped, Gram-negative and heterotrophic. To which of the major groups does it likely belong? A. Proteobacteria D. Chlamydia B. Spirochetes E. Gram-positive bacteria C. Cyanobacteria ANSWER: A 33. Which internal adaptation might enhance a prokaryote?s ability to perform metabolic processes? A. Respiratory membrane C. Plasmid B. Thylakoid membrane D. All of the above ANSWER: D 34. An endospore, this bacterial pathogen is very difficult to kill. It produces a toxin that destroys tissues and immune cells in humans. A. Bacillus anthracis C. Yersinia pestis B. Borellia burgdorferi D. E. coli ANSWER: A 35. In secondary endosymbiosis, ______________ and they develop interdependence. A. An autotrophic prokaryote lives inside a heterotrophic eukaryote B. A heterotrophic prokaryote lives inside a heterotrophic eukaryote C. A prokaryote lives inside a eukaryote D. An autotrophic eukaryote lives inside a heterotrophic eukaryote E. An autotrophic eukaryote lives inside a heterotrophic prokaryote ANSWER: D 36. Which option properly states the role of prokaryotes in eukaryotic life? A. Some prokaryotes are parasites that are deadly to eukaryotes. Therefore, eukaryotes would benefit if all prokaryotes just disappeared. B. Some prokaryotes are pathogenic to eukaryotes. However, they also play vitally important positive roles as decomposers and even as beneficial partners in the human body. The sudden disappearance of all prokaryotes would almost certainly doom most, if not all, eukaryotes to extinction. C. Prokaryotes are so small that they have relatively little influence on eukaryotes. Other than a few diseases going away, humans would not notice if prokaryotes disappeared from Earth. ANSWER: B 37. You culture the dried soup from a 4,000-year-old cooking pot found in an Egyptian tomb and obtain a distinctive species of bacteria. You immerse a test tube of these bacteria in boiling water for several hours, but the colony grows back. To which major group do they most likely belong? A. Proteobacteria D. Chlamydia B. Spirochetes E. Gram-positive bacteria C. Cyanobacteria ANSWER: E 38. Which of the following statements regarding protistan diversity is TRUE? A. Some protist lineages that obtained plastids early include species that lost them later in their evolution. B. All protists have obtained plastids at some point in their evolution. C. There are five major groups of protists, only one of which obtained mitochondria by endosymbiosis. ANSWER: A 39. You discover a bacterial colony and find under microscopy that it has a thylakoid membrane. To what major bacterial group must it belong? A. Proteobacteria D. Chlamydia B. Spirochetes E. Gram-positive bacteria C. Cyanobacteria ANSWER: C 40. Which of the following statements regarding bioremediation is FALSE? A. The downside of bioremediation is that it requires the use of dangerous pathogenic bacteria. B. Bioremediation may take advantage of the existing beneficial functions of prokaryotes on Earth and, in some cases, we may genetically engineer the functions required. C. Deinococcus radiodurans has the ability to clean some substances from radioactive waste without getting damaged. ANSWER: A 41. The methanogens that live in the human colon might also be characterized as? A. Thermophiles C. Acidophiles B. Moderate habitat archaea D. Halophiles ANSWER: B 42. Some protists have chloroplasts with three-layer membranes that allow them to produce food molecules. They likely obtained their chloroplasts by? A. Membrane infolding B. Primary endosymbiosis C. Secondary endosymbiosis ANSWER: C 43. Which of the following explains the diversity that is found among prokaryotes? A. Time on Earth C. Both B. Generation time ANSWER: C 44. Which of the following bacterial groups is least likely to include species useful in bioremediation? A. Proteobacteria D. Chlamydia B. Spirochetes E. Gram-positive bacteria C. Cyanobacteria ANSWER: D 45. As shown in the figure below by items (2) and (3), it is believed that bacteria contributed some genetic material to eukaryotes early in their evolution. Based on this representation, the material contributed in (2) is found in all eukaryotic cells, and (3) is found in only some eukaryotic cells. Based on what we have discussed, what do (2) and (3) represent? A. (2) formation of the nucleus; (3) formation of chloroplasts B. (2) formation of mitochondria; (3) formation of chloroplasts C. (2) formation of the nucleus; (3) formation of mitochondria D. (2) formation of mitochondria; (3) formation of the nucleus E. (2) formation of chloroplasts; (3) formation of mitochondria ANSWER: B Beth Microsoft Word - Exam 2a Key
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