Bio152exam1form Aanswerkey copy PDF

Preview

Summary

Download Bio152exam1form Aanswerkey copy PDF

Description

1. Some organisms, such as a chimpanzee and a gorilla, share many similarities. Others, such as a zebra and a worm have fewer similarities. What is true about the ancestors of these organisms? A. Chimpanzees and gorillas share a common ancestor with each other, but zebras and worms do not share a common ancestor B. Chimpanzees and gorillas share a common ancestor and zebras and worms share a common ancestor, but chimpanzees and gorillas do not share a common ancestor with zebras and worms C. Because chimpanzees, gorillas, zebras, and worms are all separate species, none of them share a common ancestor with each other D. Chimpanzees, gorillas, zebras, and worms all share a common ancestor 2. Darwin observed that members of a population vary in their traits. We now know that this variability is generated by: A. random DNA mutations B. adaptation of DNA C. directional selection D. allopatric speciation 3. Which of the following is a mechanism by which evolution may occur? A. Natural selection B. Artificial selection C. Genetic drift D. All of the above are mechanisms of evolution 4. Vestigial structures are: A. structures that were helpful to our ancestors but do not serve any useful purpose under current conditions B. structures that are only helpful when there is competition for survival C. structures that are harmful relics of our evolution D. structures that appear to contradict our understanding of how evolution works

5. Which of the following best describes how a complex structure like the human eye might evolve? A. The punctuated equilibrium model holds that rapid evolutionary change can occur in a relatively short time; this could produce the mutations necessary to produce a complex structure B. The eye likely evolved in a series of small changes that gradually gave organisms first the basic ability to detect light, and then eventually to form images C. Scientists still don’t know how complex structures can arise through evolution D. It likely arose through modification of another complex structure, such as the ear 6. Some animals have complex eyes and others have very simple eyes, or no eyes at all. Why is this? A. Animals with simple eyes are less evolutionarily advanced, but will eventually develop to have complex eyes B. Animals with simple eyes are incapable of undergoing mutations to develop complex eyes C. For animals that depend more heavily on other senses, there has been no selection pressure to develop complex eyes D. Animals with simple eyes have not undergone mutations needed to develop complex eyes because they don’t need them 7. The evolutionary fitness of an individual is measured most directly by A. the length of its lifespan B. the number of mates it attracts C. the number of its offspring that survive to reproduce D. the number of beneficial genes it has

8. Scientists use various methods to determine how closely two species are related. One method is to compare their physical features, and another is to compare their DNA. Can scientists also use similarities in the embyros of two animal species to help determine how closely they are related? A. No, comparing embryos of organisms does not help determine how closely two species are related. Scientists can obtain the same information comparing adult organisms B. No, comparing embryos of organisms does not help determine how closely two species are related. The embryos change too much as they grow into adult organisms C. Yes, comparing embryos is a useful way of determining how closely two species are related. There may be important similarities in the features of the embryos, even when the adults look very different. D. Yes, it is sometimes useful to compare embryos, but only when the adults are very similar

10. Which of the following correctly describes what happens when a population of bacteria becomes resistant to an antibiotic? A. During treatment with an antibiotic, each individual bacterium tries to become resistant to the antibiotic. Only some are able to willingly become resistant, and these individuals survive to pass this trait to their offspring. B. During treatment with an antibiotic, all of the bacteria gradually become more resistant to the antibiotic the more they are exposed to it. They all survive and pass this trait to their offspring. C. During treatment with an antibiotic, a population of bacteria usually dies. Sometimes by chance, all members of the population become resistant at once, survive, and pass their resistance to their offspring. D. During treatment with an antibiotic, only those individual bacteria that already have a trait that helps them survive the effects of the antibiotic will live. Their offspring in the next generation will also have this trait.

9. What is the role of fossils in supporting the theory of evolution? A. There have been many fossils of intermediate types discovered that provide strong support for the theory of evolution B. There are not enough fossils to support this theory C. Fossils of dinosaurs show that other types of life existed, but there is no evidence of relationships between them D. There are plenty of fossils to show that animals have evolved, but there are not enough fossils of human ancestors to suggest that humans are related to other animals

11. What types of mutations can contribute to genetic diversity in a population? A. Mutations that affect the coding region of a gene AND that result in an amino acid change in that gene B. Mutations that rearrange chromosomes and that can result in increased or decreased expression of that gene C. Mutations that result in chromosomal duplications D. Mutations that affect regulatory regions of a gene E. All of the above can contribute to genetic diversity in a population

2

12. What effects do mutations have on organisms? A. All mutations are harmful because they disrupt protein function or gene regulation B. All mutations are beneficial to organisms because they improve protein function or gene regulation C. All mutations have no effect on organisms, because they do not significantly affect protein function or gene regulation D. Some mutations are harmful, some are beneficial, and some have no effect on the organism

15. Using data from the previous question, what is the frequency of white alleles in the population? A. 0.2 B. 0.4 C. 0.6 D. 0.7 E. 0.8 16. In a separate population of unicorns, some individuals have horns and others do not. The frequency of the horn allele in the population is 0.4. What is the expected frequency of individuals homozygous for the horn allele? A. 0.16 B. 0.2 C. 0.4 D. 0.6 E. 1.6

13. Which Hardy-Weinberg condition is affected by population size? A. selection B. genetic drift C. gene flow D. no mutation

17. Using data from the previous question, what is the expected frequency of individuals HETEROZYGOUS for the horn allele? A. 0.08 B. 0.16 C. 0.24 D. 0.48 E. none of the above are correct

14. In a population of 500 unicorns, there are two alleles for mane color: R for rainbowcolored and r for white. In this population: 100 unicorns are homozygous for the rainbow allele 200 unicorns are heterozygous for the rainbow/white allele 200 unicorns are homozygous for the white allele What is the frequency of rainbow alleles in the population? NOTE THAT CALCULATORS ARE NOT ALLOWED ON THIS EXAM. ANY STUDENT USING A CALCULATOR WILL RECEIVE A GRADE OF 0 ON THE EXAM A. 0.2 B. 0.3 C. 0.4 D. 0.6 E. 0.8

18. The bottleneck effect is an example of: A. natural selection B. artificial selection C. genetic drift D. none of the above 19. The term “gene flow” refers to: A. When individuals enter or leave a population B. The loss of alleles when a population becomes endangered C. When natural selection changes the makeup of alleles in a population D. When scientists genetically manipulate organisms to create or remove alleles

3

24. Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification? A. The two forms interbreed often in nature, and their offspring survive and reproduce well B. The two forms live in similar habitats and have similar food requirements C. The two forms have many genes in common D. The two forms are very similar in appearance

20. If two populations of the same species are separated and stop reproducing with each other, which of the following MUST be true? A. The two populations will become different species B. The two populations will become reproductively isolated C. If new alleles arise through mutation in one of the populations, those alleles will not be transferred to the other population D. Any mutations that occur in one population will also occur in the other population because the two populations are the same species 21. A biologist doing a long-term study on a wild spider population decreased average silk thickness in the population over time. Which of the following could the spider population be experiencing? A. directional selection B. stabilizing selection C. disruptive selection D. genetic drift

25. According to fossil evidence, the first life on Earth: A. Was a single-celled organism that lived in the ocean B. Was an animal that lived in the ocean C. Was a plant that lived in the ocean D. Was a plant that lived on land E. Was a single-celled organism that lived on land

22. Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact? A. a temporal reproductive isolating mechanism B. a postzygotic isolating mechanism C. a behavioral reproductive isolating mechanism D. a gametic reproductive isolating mechanism

26. What is believed to be the most significant result of the evolution of the amniotic egg? A. Tetrapods are no longer tied to the water for reproduction. B. Tetrapods can now function with just lungs. C. Newborns are much less dependent on their parents. D. Embryos are protected from predators. 27. Monotremes are mammals but like reptiles, they: A. lack hair B. do not lactate C. lay eggs D. lack the ability to thermoregulate

23. Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms? A. temporal isolation B. behavioral isolation C. habitat isolation D. gametic isolation

4

28. Which of the following best describes the evolutionary relationship between modern humans and chimpanzees? A. Humans are descended from chimpanzees B. Humans and chimpanzees had a common ancestor several million years ago C. Humans and chimpanzees had a common ancestor several million years ago; since that time, humans have evolved more than chimpanzees D. Chimpanzees are more closely related to gorillas than they are to humans

32. The Cambrian Explosion was a period of more rapid evolution. This is believed to be because: A. The earth cooled and water levels went down B. The earth warmed making many areas more habitable C. Land first rose out of the oceans during this time D. Oxygen levels in the atmosphere increased sharply

29. Bipedalism was an important event for human evolution because: A. it made us faster runners B. it allowed us to better use tools C. it allowed our brains to become larger D. it allowed us to better care for our offspring 30. The human “notochord” is the: A. Spinal column B. Tail C. Spinal cord D. Pharyngeal slits 31. Allopolyploidy and autopolyploidy are both more common in plants than in animals. This is because A. Plants are more likely to mate with other species than animals B. Plants can sexually reproduce with themselves C. Plants are more likely to undergo errors during meiosis D. In plants, homologous chromosomes do not pair up during meiosis

5...