31

What evolutionary question is better addressed by the fig-shaped evolutionary tree in //cnx.org/contents/This email address is being protected from spambots. You need JavaScript enabled to view it.:1b474466-e8e9-4039-a517-0b2db77743eb#fig-ch20_03_05" data-page="217">Figure 20.17, as opposed to the more typical, single-trunk phylogenetic tree in //cnx.org/contents/This email address is being protected from spambots. You need JavaScript enabled to view it.:e5e51e35-ba7e-45da-889f-a72f1b2e1f13#fig-ch20_01_01" data-page="215">Figure 20.2?

  1. What was the single organism from which all other forms of life on Earth arose?
  2. Did animals evolve from fungi?
  3. In which species of eukaryote did chloroplasts first appear?
  4. Were chloroplasts and mitochondria transferred to eukaryotic cells through horizontal gene transfer?
32.
Which question, relating to the endosymbiotic hypothesis and the evolution of eukaryotes, is not answered by the eukaryote-first hypothesis, based on the figures?
  1. Which evolved first, the nucleus or prokaryotes?
  2. Which evolved first, mitochondria or prokaryotes?
  3. How and when did the nucleus evolve in eukaryotes?
  4. How and when did prokaryotes evolve?
33.
alt textThe phylogeny above shows the evolution of traits in vertebrates. Based on this phylogeny, a student asks “Does this mean that lizards, frogs and rabbits all possessed hair and an egg with amnion at some point in their evolution?” Based on the phylogeny, how should you respond to the student?
  1. Hair and an amniotic egg were both possessed by all three species at some point in their evolution.
  2. Hair is only a characteristic found in the rabbit evolutionary history. The amniotic egg was possessed by both the rabbit and lizard, but not frogs, at some point in their evolutionary history.
  3. Hair is a characteristic only found in the rabbit evolutionary history. The amniotic egg was possessed by all three species at some point in their evolutionary history.
  4. Hair was possessed by all three species at some point in their evolutionary history. The amniotic egg was possessed by both the lizard and frog, but not the rabbit at some point in their evolutionary history.
34.
alt textThe tree above shows the phylogenetic relationships between four species. A scientist wishes to perform a genetic analysis on all four species in which she determines the number of genetic similarities between all four species. What would she likely find regarding the genetic similarities between species A, B, D and E?
  1. Species D and E would share more genetic similarities with each other than with species A and B, and vice versa.
  2. Species A and E would share more genetic similarities with each other than with species B and D, and vice versa.
  3. Species D and A would share more genetic similarities with each other than with species A and B, and vice versa.
  4. Species D and B would share more genetic similarities with each other than with species A and E.
35
What is the aim of scientists applying the maximum parsimony concept when creating phylogenetic trees?
  1. The scientists spend more time creating the phylogenetic table.
  2. Scientists find the shortest tree with the smallest number of changes.
  3. A complex, detailed phylogenetic tree diagram is created.
  4. The scientists spend more time researching the data for evolutionary connections.
36
Dolphins and fish have similar body shapes. Is this feature more likely a homologous or analogous trait? Explain your answer.
  1. Analogous-Dolphins are mammals and fish are not, thus their evolutionary paths are quite separate. They have similar body shapes because of their similar environment.
  2. Analogous-Dolphins and fish are both vertebrates, thus they share an evolutionary history, causing them to have similar body shapes.
  3. Homologous-Dolphins and fish are both vertebrates, thus they have a similar recent evolutionary history, causing them to have similar body shapes.
  4. Homologous-Dolphins are mammals and fish are not, thus their evolutionary paths are quite separate. They have similar body shapes because of their similar environment.
37
What effect has the advancement of DNA technology had on determining phylogeny?
  1. Morphologic and molecular information often disagree.
  2. Scientists are struggling with molecular systematics.
  3. Information is not reliable because organisms appear to be closely related when they are not.
  4. Computer programs help determine relatedness using DNA sequencing, and morphologic and molecular information is more effective in determining phylogeny.
38
Describe what maximum parsimony is used for in evolutionary biology.
  1. Maximum parsimony hypothesizes that organisms that share the most traits are the most likely to share a common ancestor.
  2. Maximum parsimony hypothesizes that organisms that share a common ancestor are more likely to have many traits in common.
  3. Maximum parsimony hypothesizes that events occurred in the simplest, most obvious way, and the pathway of evolution probably includes the fewest major events that coincide with the evidence at hand.
  4. Maximum parsimony hypothesizes that organisms that display homologous structures are closely related, while organisms that display analogous structures must have diverged much farther in the past.
39
The emu in Australia and ostrich in Africa are flightless birds that look similar. One proposed hypothesis was the birds descend from an early common ancestor that spread when the continents were connected. DNA analysis shows that emus and ostriches share more genetic homology with flying birds which live in the same region than with each other. What is the best explanation for these findings?
  1. This is an example of an early shared ancestor.
  2. This is an example of convergent evolution.
  3. This is an example of random DNA homology.
  4. This is an example of divergent evolution.
40
A scientist decides to investigate the evolutionary connection between closely related bacteria. Which gene would be a good choice to use for establishing relatedness, a very well conserved gene or a poorly conserved sequence? Explain your reasoning.
  1. A very well conserved gene would be a good choice, because well conserved genes undergo sufficient changes during relatively short times, which allows for the study of recent evolutionary events. Well-conserved genes do not undergo changes during short durations.
  2. A poorly conserved gene would be a good choice, because poorly conserved genes show sequence similarity, which is used as evidence of evolutionary relationships between sequences.
  3. A poorly conserved gene would be a good choice, because poorly conserved genes undergo sufficient changes during relatively short times, which allows for the study of recent evolutionary events.
  4. A very well conserved gene would be a good choice, because well conserved genes show sequence similarity, which is used as evidence of evolutionary relationships between sequences.
41.
In a hypothetical population of beetles, there is a wide variety of color, matching the range of coloration of the tree trunks on which the beetles hide from predators. The graphs below illustrate four possible changes in the beetle population as a result of a change in the environment due to pollution that darkened the tree trunks. What would be the most likely change in the coloration of the beetle population after pollution and why?
  1. The coloration range shifted toward more light-colored beetles, as in diagram I. The pollution helped the predators find the darkened tree trunks.
  2. The coloration in the population split into two extremes, as in diagram II. Both the light-colored and the dark-colored beetles were able to hide on the darker tree trunks.
  3. The coloration range became narrower, as in diagram III. The predators selected beetles at the color extremes.
  4. The coloration in the population shifted toward more dark-colored beetles, as in diagram IV. The light-colored beetles were found more easily by the predators than were the dark-colored beetles.
42
A population of rodents settles on the shore of an island close to the Arctic Circle. The landscape consists mainly of rocks. If the individuals are too large, they cannot hide in crevices to escape hawks. On the other hand, small bodies do not maintain internal temperature in cold weather. Show diagrammatically the change in the population and explain what selective pressures took place.
  1. directional selection
  2. stabilizing selection
  3. disruptive selection
  4. diversifying selection
43

Five new species of bacteria were discovered in Antarctic ice core samples. The nucleotide (base sequences of rRNA subunits were determined for the new species. The table below shows the number of nucleotide differences between the species.

Species12345
1 - 3 19 18 27
2   - 19 18 26
3     - 1 27
4       - 27

Which of the following phylogenetic trees is most consistent with the data?

44

Draw the phylogenetic tree for the species below. Identify where on the tree each feature evolved.

.
Figure 20.20
  1. The ostrich branched off first, followed by the snake, then the frog, then the shark and then the lancelet.
  2. The shark branched off first, followed by the lancelet, then the frog, then the ostrich and then the snake.
  3. The lancelet branched off first, followed by the shark, then the frog, then the snake and then the ostrich.
  4. The lancelet branched off first, followed by the shark, then the ostrich, then the snake and then the frog.
45
Barbara McClintock discovered transposons while working on maize genetics. What are the transposons composed of when they are able to shift from one location to another?
  1. segments of RNA
  2. Plasmids
  3. segments of DNA
  4. proteins
46
What is Horizontal Gene Transfer (HGT)?
  1. the proposal that eukaryotes developed a nucleus first, and then their mitochondrion
  2. the transmission of genetic material from one species to another through mechanisms other than from parent to offspring
  3. the fusion of two prokaryotic genomes
  4. the division of kingdom in the taxonomic classification
47
What is referred to as the transfer of genes by a mechanism that does not involve asexual reproduction?
  1. web of life
  2. meiosis
  3. gene fusion
  4. horizontal gene transfer
48
Which of the following describes small, virus-like particles that act as a mechanism of gene transfer between prokaryotes?
  1. gene transfer agents
  2. horizontal gene transfer
  3. vertical gene transfer
  4. basal taxon