Biology Exam Key

1. Which of the following "count" as examples of biological evolution? A. A tadpole grows legs, loses its tail, develops lungs, and emerges as a tiny toad fully capable of life on land. B. In a population of frogs, a genetic type that has a longer tongue becomes more common over hundreds of years. C. The genetic makeup of the human population of Australia changes when European settlers arrive, add to, and mix with the Aboriginal population. D. A woman moves high into the Himalaya Mountains where the air is very thin. Within two weeks, she grows extra red blood cells and changes in other ways that allow her to breathe easier. 1) All of the choices 2) B and C 3) A and D 4) B only 5) C only 2. Which of the trees to the right depicts an evolutionary history different from the other two? 1) a 2) b 3) c 3. Which mechanism of evolution always increases fitness and leads to adaptation? 1) natural selection 2) mutation 3) gene flow 4) genetic drift 4. Thinking about the work we did with dog evolution, which statement below is true? 1) All dogs are domesticated wolves. 2) Different dog types (such as a Boxer and Chihuahua) are the result of the mixing of different types of dogs, such as jackals x coyotes and wolves x coyotes. 3) A Boxer, Greyhound, and Chihuahua represent different species of dogs. 4) More than one choice above is true. 5. A species of impatiens endemic to New Guinea displays three colors of flowers: red, white, and pink. Pink flowers are due to incomplete dominance, resulting in a heterozygote with an intermediate phenotype. Scenario: A few impatiens plants drifted to a nearby island and were quickly established. All three flower colors were initially seen within this new island population. However, 20 generations later, only impatiens with white flowers were found on the small island. During the next decade several hurricanes in the area caused more plants of this impatiens species to be dispersed to the same small island, after which all three flower colors were seen there again. Unfortunately, two years later a volcano erupted, wiping out 99% of the impatiens population on the island. Sequence these processes in the order in which they occurred in the scenario. gene flow bottleneck effect genetic drift founder effect                1) gene flow founder effect genetic drift bottleneck effect 2) gene flow bottleneck genetic drift founder effect 3) founder effect genetic drift gene flow bottleneck effect 4) bottleneck effect genetic drift gene flow founder effect 5) genetic drift founder effect gene flow bottleneck effect 6. The ability to taste PTC is a dominant allele (T). You sampled 1000 students in biology and determined that 640 students could taste PTC. What is the frequency of the recessive allele in the population? 1) 0.64 2) 0.36 3) 0.6 4) 0.03 5) none of the choices 7. Turtles and crocodiles are all part of the clade known as reptiles. Based on the phylogenetic tree to the right, which statement(s) is FALSE? A) Birds are reptiles. B) Birds are ancestors of dinosaurs. C) Birds are more evolved than turtles. 1) A, B, and C 2) B and C 3) A only 4) B only 5) C only 8. A new species can arise in a single generation __________. 1) through geographic isolation. 2) in a very large population spread over a large area. 3) if a change in chromosome number creates a reproductive barrier. 4) if sexual selection occurs 5) if adaptive radiation occurs. 9. An antibiotic kills 99.9% of a bacterial population. You would expect the next generation of bacteria: 1) to be just as susceptible to that antibiotic as was the previous generation. 2) to be more resistant to that antibiotic. 3) to die out due to the drastic decrease in population size. 4) to be more contagious than the prior generation. 5) all of the choices are correct. 10. Organisms on land are unlikely to: 1) have internal fertilization. 2) package their embryos in an amniotic egg 3) have waterproof skin 4) have long flat skulls 5) have bony limbs 11. Which of the following statements about oogenesis is FALSE? 1) A secondary oocyte has less genetic content than a primary oocyte. 2) When a secondary oocyte forms, the polar body formed alongside it receives none of the genetic content. 3) At the time of ovulation, meiosis is not yet complete. 4) By the time a female baby is born, oogenesis has already begun. 5) Most of the time, only one secondary oocyte develops each month. 12. In an experiment, female warbler birds that had laid several eggs in their nest had one egg replaced with a cuckoo egg. The cuckoo’s egg was similar looking to the warbler eggs. Sometimes the warblers ejected the cuckoo eggs from her nest and sometimes they did not. What hypothesis was likely being tested by this experiment? (Use data to the right too.) 1) Cuckoo eggs that look more similar to warbler eggs in their coloring (better mimicry) were ejected less. 2) Cuckoo birds lay their eggs in young warbler nests rather than old because they survive better. 3) Cuckoo birds are social parasites of warblers. 4) Warblers who have reproduced many times learn how to spot parasitic eggs better. 13. Evident in three-toed sloths is a greenish color of the hair, which is due to green algae. Scientists are examining the relationship to see if chemical compounds produced by the algae give sloth hair a desired texture or allow beneficial bacteria to grow in it. By asking this question, scientists are most likely looking for evidence of: 1) parasitism 2) herbivory 3) mutualism 4) competition 5) predation (Warbler age) Use the table to answer the next four questions: Scientists have been studying two species of dragonflies, Sympetrum strilatum and Sympetrum nigrescens (the darker body color). Below are some fictional data about these two species. Species Body color Most often located in: Tagging (July 2009) Sympetrum strilatum Light Various locations in 100 tagged initially, 1000 England captured on second visit and 10 had tags Sympetrum nigrescens Dark West Scotland 100 tagged initially, 1000 captured on second visit and 2 had tags 14. Which statement is correct about the dragonflies? 1) The population size of Sympetrum strilatum is larger and is about 5,000. 2) The population size of Sympetrum strilatum is larger and is about 5,000. 3) The population size of Sympetrum nigrescens is larger and is about 2,000. 4) The population size of Sympetrum nigrescens is larger and is about 50,000. 5) none of these are correct 15. Scientists tagging the two different species realized they were tagging them differently. In fact, they learned that the tags used in the population studies with Sympetrum nigrescens were negatively affecting their survival because tagged animals were more likely to be impaired in their flying and more likely to be eaten by a predator. Is the population size estimate likely to be too high or too low compared to the actual number because of the detrimental tags? 1) estimation is too low 2) estimation is too high 16. Scientists noted that when put together in containers, the dragonflies could produce fertile offspring and the offspring successfully reproduced. What is a likely reason(s) why these two dragonflies remain distinct species in nature? 1) habitat isolation 2) mechanical isolation 3) reduced hybrid viability 4) choices 1 & 3 17. The ancestor of these two dragonfly species was a species that was light in color. However, the weather in West Scotland is such that the sun doesn’t shine for very long in between the grey clouds most days. Thus, the darker color is believed to be an adaptation to warm the Sympetrum nigrescens dragonfly in the short bursts of sunshine. The evolution of Sympetrum nigrescens from its ancestral species is an example of: 1) disruptive selection 2) directional selection 3) stabilizing selection 18. Two scientists discover populations of fish in caves not previously explored. They find one population of the fish lives near the surface of the water and another population lives in the depths. Both populations of fish appear identical. The scientists make an initial hypothesis that there are actually two species. They are using the _____________ species concept. 1) morphological 2) ecological 3) phylogenetic 4) biological 19. Diane Dodd, a scientist from Yale University raised fruit flies on different food sources. Some populations were fed starch and some were fed maltose. After about 40 generations those raised on starch digested starch more efficiently and those raised on maltose digested maltose more efficiently. When Dr. Dodd had flies from starch populations mix with flies from maltose populations the flies often mated more with flies raised on the same food source. What was Dr. Dodd testing with this experiment? 1) the evolution of reproductive barriers 2) if food sources could lead to directional selection 3) if evolution occurs with long periods of little morphological change punctuated with sudden bursts of rapid change Use the data to the right to construct a phylogenetic tree and answer questions about it: 20. The species that diverged first from the others is/are: 1) S 2) P 3) P and Ro 4) C 5) C and D 21. Of the four traits listed below, which one evolved most recently? 1) bony skeleton 2) vertebrae 3) hair 4) amniotic egg 22. Which of these is an example of negative feedback? 1) As a blood clot begins to form, the process of its formation gets faster and faster. 2) A person who loses 3 pounds continues to diet to lose an additional 10 pounds. 3) Once labor begins, contractions increase in frequency and intensity. 4) After eating a high glucose snack, insulin stimulates the lowering of blood sugar levels 5) The smell of bacon increases gastrin levels which increase stomach acid production 23. Why would one predict that if King Kong (see picture on right) existed he would be hairless? 1) The weight of the hair would be too much for his body to support. 2) Due to the extreme amount of heat his body would generate, the presence of hair would likely overheat him. 3) The presence of hair would prevent him from sufficiently warming up via the sun 4) It would require too much energy to maintain that amount of hair 24. Which of the following structures in females is analogous in function to the vas deferens in males? 1) ovaries 2) oviduct 3) vagina 4) urethra 5) cervix 25. Fish with parental care are likely to suffer what cost? 1) produce fewer young 2) only reproduce once 3) offspring have a lower chance of survival 4) have smaller offspring 26. Pituitary tumors run in Jackie’s family. A continuous _____________ would be the most direct observable effect of a pituitary tumor and give Jackie’s physician reason to worry. 1) high level of estrogen 2) low level of estrogen 3) high level of progesterone 4) low level of progesterone 5) high level of FSH 27. To the right is a hormone fluctuating throughout a 24 hour period. The subject was told to eat when she felt hungry. The times that she ate a meal are shown with vertical lines. Which statement below is supported by the data? 1) If hormone levels are high a person will likely eat a large meal. 2) An obese person is more likely to have high rather than low levels of this hormone. 3) both 4) neither 28. The surgical removal of the seminal vesicle would likely 1) cause sterility because sperm would not be produced 2) have no effect on sperm function or fertility because this is a vestigial ancestral structure with no known function in modern humans 3) greatly reduce the volume of semen 4) cause the testes to migrate back into the abdominal cavity 5) cause sterility because sperm would not have an exit from the body 29. After progesterone and estrogen peak and fall in a woman’s cycle, what would occur next? 1) ovulation 2) menstruation 3 follicle growth 4) uterus growth 5) a peak of LH and FSH 30. Which of the following would be the most likely outcome if androgen receptors on cells in the hypothalamus and anterior pituitary suddenly could not bind androgen? 1) Sperm production would decrease 2) HCG production would increase 3) FSH production would decrease 4) sperm production would increase.