exam 2 version a

Foundations of Ecology and Evolution Fall 2014 – Form A

Exam 2 – Section 3 – November 4, 2014

Instructions:

• You can write on this test booklet. • Choose the best answer. • All answer must go on the scantron. • Calculators are NOT allowed. • Sign the academic integrity code on the

bottom of this page. • Make sure to write your name, form

letter, and section number on the scantron

University Code on Academic Integrity On this date of November 4, 2014 understand the University Code on Academic Integrity, and here by abide by all sections. I will not aid or be assisted by colleagues within this class, which may infringe upon violating both Rutgers and NJIT Integrity codes. Print Name:____________________________________ Signature:______________________________________ YOUR EXAM WILL NOT BE GRADED UNLESS THE ACADEMIC

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FORM A


Figure 1: This phylogeny show the evolutionary relationship of several groups of animals. The cartoons represent living groups of animals. The letters lower on the tree represent ancestral species. For 1 & 2 indicate whether the statement is correct by circling the letter next to the TRUE or FALSE statement with the correct reason. 1. According to Figure 1, Newts are more closely related to Sunfish than to Chimpanzees. A) TRUE, because newts share a common ancestor with sunfish. B) TRUE, because newts are closer to sunfish in the tree. C) TRUE, because the ancestor of sunfish (Q) is connected to the ancestor of newts (R) whereas the ancestor of chimpanzees (T) is separated by one ancestor (S). D) FALSE, because newts share a more recent common ancestor with chimpanzees than with sunfish E) FALSE, because newts are much more primitive than chimpanzees 2. According to Figure 1, newts evolved from sunfish A) TRUE, because sunfish came first. B) FALSE, because sunfish evolved from newts. C) FALSE, because newts evolved from lizards. D) FALSE, because neither evolved from the other. 3. In figure 1, Chimpanzees, bears, and ancestral species T are the only members of the mammal clade. If a trait is a synapomorphy of mammals, then A) It should be present in the ancestor S B) It should be present in the ancestor T C) It should be present in both S & T D) It should not be present in either S or T


4. Which of the following is the correct sequence of events in evolution of life on earth (from most ancient to most recent)? I. origin of mammals II. origin of arthropods III. origin of life on land IV. origin of photosynthesis A) I, II, III, IV B) III, II, IV, I C) IV, III, II, I D) I, III, IV, II E) IV, II, III, I 5. Which of the following is NOT an example of sympatric speciation? A) a few individuals of a species start a new population on an island, after 2 million years,

this new population has become reproductively isolated from the mainland population. B) a species of insect diverges into two species while living in the same area due to a

preference for feeding on different substrates. C) a species of fish living in a lake diverges into two species because a dam is build that

divides the lake into two and keeps the two populations separated. D) a species of plant diverges into two after a meiotic mutation leads to the production of

individuals with the wrong number of chromosomes, these individuals then form a new breeding population .

E) Both A & C are NOT examples of sympatric speciation.

6. The figure above shows the decay of C-‐14 to N-‐14. If you have a fossil that is 10,000 years old, approximately how much C-‐14 should be left compared to the original amount the fossilized remain started with? A) Between 100 – 50% B) Between 50-‐25% C) Between 25 – 12.5% D) Between 12.5 – 7.25% E) Less than 7.25%

Years elapsed


7. The group shaded in the tree above is a __________________ group. This group includes only species B & C.

A) Monophyletic B) Paraphyletic C) Polyphyletic 8. The basic diploid chromosome number in Rye (Secale cereal) is 14. A new species of rye is found that has 28 chromosomes. This species is said to be _________ A) haploid B) diploid C) triploid D) tetraploid E) octoploid 9. Which of the following occurred during the Paleozoic? A) Origin of life B) Origin of multicellular life C) Origin of photosynthesis D) Origin of amphibians E) Origin of mammals 10. Why would natural selection favor lactase persistence in some populations but not others? A) In some populations people might be lactose intolerant, so drinking milk would not provide a selective advantage. B) If a mutation enabling lactase persistence occurred in a population that did not have access to dairy animals, it would not be selected for (i.e., there would be no positive selection). C) Any mutations altering the production of lactose would be selected against D) This mutation only occurred because of the presence of dairy animals near the human population. E) lactase persistence is a ancestral trait that has been lost in several population of humans because they no longer needed this trait.

E


11. The proliferation of a large number of daughter species from a single ancestor is known

as A) an adaptive radiation. B) the Cambrian explosion. C) sympatric speciation. D) disruptive selection. E) cospeciation. 12. Which of the following is the most likely sequence of events in allopatric speciation? A) Geographic separation, reproductive isolation, genetic divergence B) Geographic separation, genetic divergence, reproductive isolation C) Genetic divergence, geographic separation, reproductive isolation D) Genetic divergence, reproductive isolation, geographic separation E) Reproductive isolation, genetic divergence, geographic separation 13. Similarity of phenotypes may bot always reflect evolutionary relationships A) due to convergent evolution. B) due to homologous traits. C) due to both of the above. 14. Two species of wild lettuce grow in the same areas, but one flowers in early spring and the other flowers in summer. This is an example of a A) postzygotic isolating mechanism B) geographical isolating mechanism C) behavioral isolating mechanism D) temporal isolating mechanism E) Both A & D 15. Currently, two extant elephant species (X and Y) are placed in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which statement should be true? A) Species X and Y are not related to species Z. B) Species X and Y share a greater number of homologies with each other than either does with species Z. C) Species X and Y share a common ancestor that is still extant (in other words, not yet extinct). D) Species X and Y are the result of artificial selection from an ancestral species Z. E) Species X, Y, and Z share a common ancestor, but nothing more can be claimed than this. 16. Which of the following is true about life in the Precambrian? A) There were only single-‐cell organisms on earth B) There was no oxygen on earth throughout the entire Precambrian C) There were no animals on earth D) All life was marine (i.e., found in the ocean) E) All living organisms on earth at this time had a nucleus


17. According to the principle of parsimony, the best phylogenetic hypothesis is the one that requires the A) fewest homologies. B) most evolutionary steps. C) fewest evolutionary steps. D) most clades. E) fewest clades. 18. The antifreeze proteins found in fish that live in very cold waters has evolved

independently in the Arctic and in the Antarctic, and not because of shared ancestry. Which of the following can be said about its evolution?

A) The antifreeze proteins in Arctic and Antarctic fish are homologous traits. B) The antifreeze proteins in Arctic and Antarctic fish are analogous traits. C) The Arctic and Antarctic fish form a clade. D) Both a and c E) None of the above 19. According to the diagram below, which of the three phylogenetic trees of the Drosophila

species is different from the other two?

A) Tree 1 B) Tree 2 C) Tree 3 D) All of the trees are the same


20. Which of the following statements about oxygen and ancient Earth is true? A) The atmosphere of early Earth contained almost as much free oxygen as present-‐day

Earth, but most of this oxygen was lost in the Cambrian. B) Early bacteria generated free oxygen as a product of photosynthesis. C) The oxygen-‐generating cyanobacteria have gone extinct. D) All of the above E) None of the above 21. You are studying a hypothetical virus VIR. This virus has jumped into the human

population twice, once from gorillas and once from orangutans. You have categorized the virus in humans into two types: VIR-‐G (the one that came from gorillas), and VIR-‐O (the one that came from orangutans). In VIR-‐O there is a huge variety in strains (lots of genetic diversity), however in VIR-‐G there is very little diversity. This suggests:

A) that VIR-‐O entered the human population more recently than VIR-‐G B) that VIR-‐G entered the human population more recently than VIR-‐O C) that both viruses entered the human population around the same time 22. The common ancestor of humans and the other “great apes” walked on all fours, while

humans are bipeds. Bipedalism is thus the _______ trait. A) ancestral B) homologous C) paraphyletic D) derived E) monophyletic 23. You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use? A) biological B) evolutionary C) ecological D) morphological 24. Which of the following represents a correct size ranking of taxonomic categories, from

the smallest to the largest? A) Family, genus, phylum, species B) Species, genus, phylum, family C) Species, genus, family, phylum D) Genus, species, family, phylum E) None of the above are in correct order


25. Both ray-‐finned fish, and primates have a bony skeleton. According to the phylogenetic tree, this is a result of: A) homology B) shared common ancestry C) convergent evolution D) an evolutionary reversal E) Both A & B 26. An animal breeder, attempting to cross a llama with an alpaca for finer wool, found that the hybrid offspring rarely lived for more than a few weeks. This outcome probably results from: A) genetic drift B) prezygotic isolation C) postzygotic reproductive isolation D) sympatric speciation E) polyploidy 27. During the Permian mass extinction: A) oxygen levels in the deep oceans dropped. B) global warming occurred as a result of volcanic eruptions. C) volcanoes emitted massive quantities of lava. D) All of the answer options are correct.


28. Gus and Ida are 2 polar bears (Ursus maritimus) that live at the Central Park Zoo in New York City. They are 1st generation zoo polar bears. They have lived at the zoo since 1985. The Zoo decides to keep all of Gus and Ida’s descendants under zoo conditions for the next 30,000 years. They breed only with each other. You visit the zoo in 30,000 years and see their descendants. Do you expect their descendants, which are alive in 30,000 years, to be identical in genotype and phenotype to Gus and Ida? Keep in mind, polar bears start reproducing when they are between 5 and 10 years old, and adult females give birth to 2 cubs every 2-‐3 years. A) Yes, because evolution only occurs in nature. B) Yes, because they had a small population to begin with (only 2 bears) so there was little genetic variation to start. C) No, because mutation would occur occasionally and there are selective pressures that exist in artificial as well as natural environments. D) No, because evolution only occurs in nature 29. Which of the following terms refers to ancestors that are more closely related to modern humans than to our nearest relatives, the chimps? A. apes B. great apes C. primates D. hominins E. prosimians 30. Some species of stick insects have wings, while others are wingless. Using the phylogenetic tree and the principle of parsimony, how many times did wings most likely evolve? A) 1 B) 2 C) 3 D) 4 E) Both options B & C are equally likely. 31. Oxygen A) was prevalent in the atmosphere of Earth 3.8 billion years ago. B) allowed for the evolution of photosynthetic organisms. C) is toxic to all cells. D) made aerobic life possible. E) is made by respiration.


32. The diagram on the right represents the ranges of 3 species (A, B, and C), which are separated by a mountain range and river. Jane B. Geographer has hypothesized that these three species arose via vicariance. Specifically, she has proposed that the area was originally occupied by a single species. Its range was split first by the mountain range. Later, the river formed, separating populations on the eastern side of the mountains. If her hypothesis is correct, phylogenetic analysis should reveal that

A) Species B and C are each other's closest relatives B) All three species are equally related C) Species A and C are each other's closest relatives D) Species B and A are each other's closest relatives. 33. A new species of organism has evolved when A) the climate of a population's area has changed greatly. B) a population can no longer interbreed under natural conditions with other closely related organisms. C) variation has occurred within the species due to mutations. D) a population has been recently isolated from the rest of the species by a geographic barrier. E) natural selection has occurred.

34. If, due to a massive flooding event, three populations become isolated from each other preventing gene flow, what will likely happen to the populations over time? A) They will start to diverge genetically due to genetic drift. B) They will start to diverge genetically due to minor differences in their respective environments. C) They will each lose genetic variation due to drift. D) All of the above. E) All except (A). 35. Population A & B are geographically separated. An increase in gene flow between the two populations will: A) likely speed up the speciation process between the two populations. B) likely slow down the speciation process between the two populations. C) have no effect on the speed of speciation. D) induce mutations in the population. E) lead to immediate reproductive isolation.


36. According to the figure above, humans are members of the monophyletic: A) Chimpanzee group B) Apes group C) Primates group D) Both B & C E) All of the above 37. Primates: A) are a type of monkey B) are a type of great ape C) are mammals D) have nails instead of claws E) both C & D are correct


38. Humans and chimpanzees diverged about 6 million years ago. If 12 nucleotide substitutions have occurred between human and chimpanzee lineages in a sequence of mitochondrial DNA, and 36 have occurred between humans and gibbons, humans and gibbons, according to the molecular clock, separated _______ million years ago. A) 6 B) 12 C) 18 D) 36 39. Which of the following is TRUE regarding hominins? A) There were never more than one living species on hominin on earth at the same time. B) The only hominin species to ever live outside of Africa is Homo sapiens. C) All lineages of ancient hominins belong to the genus Homo. D) There is only one extant (currently living) species of hominin. E) Chimpanzees are hominins. 40. In a phylogenetic analysis an outroup A) is the common ancestor of our ingroup. B) helps us determine which character states are ancestral and which are derived. C) helps us decide which molecular data to use. D) is usually very distantly related to our ingroup E) Both A & B Bonus questions: 41. Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial. Today, penguins (which are birds) and seals (which are mammals) have forelimbs adapted for swimming. What term best describes the relationship of the four limbs found in both penguins and seals, and what term best describes the flippers of penguins and seals? A) homologous; homologous B) analogous; homologous C) homologous; analogous D) analogous; analogous 42. Read through the following statements about bacteria:

• All bacteria are pathogenic • All bacteria are useful to humans • Some bacteria have a nucleus • Certain bacteria in our guts help us break down complex carbohydrates • Some bacteria are photosynthetic • There are no mutualistic bacteria

How many of the above statements are TRUE? A) 1 B) 2 C) 3 D) 4

exam 2 version a

Documents

ancestor of chimpanzees

ancestor of newts r

ancestor t c

ancestor of sunfish

b false

c false

d false

ancestor s b