Deck 15: Intimate Partnerships: How Species Adapt to Each Other

Question 1

Which statement does the following figure support?

A) Mitochondria are capable of living outside of eukaryotic hosts.
B) Mitochondria evolved from Pelagibacteraceae.
C) Mitochondria are more closely related to marine Pelagibacteraceae than they are to the disease-causing Rickettsiaceae.
D) all of the above

Answer 1

C

Question 2

How can mobile genetic elements behave like genomic parasites?

A) They can disrupt a cell's normal rhythm of growth and division.
B) They can make a vital protein nonfunctional.
C) They can increase the fitness of their hosts.
D) a and b
E) a, b, and c

Answer 2

D

Question 3

Which of the following is an example of antagonistic coevolution driving up the number of species in a clade?

A) rabbits and the myxoma virus
B) butterfly larvae and milkweed plants
C) Joshua tree and yucca moths
D) ants and plants that produce elaiosomes

Answer 3

B

Question 4

Organelles that function in energy conversion, which are endosymbionts in eukaryotic cells, include

A) mitochondria.
B) chloroplasts.
C) flagella.
D) a and b
E) a, b, and c

Question 5

Which of the following describes the relationship between a grass and mycorrhizae, an underground fungus?

A) commensalism
B) mutualism
C) herbivory
D) parasitism

Question 6

Coevolutionary alteration is likely to occur when

A) interactions are mutualistic.
B) parasite and host populations exert negative frequency-dependent selection on one another, if the parasite has the option of switching to another host species.
C) host populations are under stabilizing selection.
D) a single host is available to parasites.

Question 7

What preliminary evidence suggests that coevolution may be a driving factor of speciation in Joshua trees?

A) Within the range of the Joshua tree, it is pollinated by two different moths.
B) When Tegeticula synthetica and T. antithetica diverged from a common ancestor, each specialized on only one population of Joshua tree.
C) Joshua tree flower morphology has diverged as a result of moth speciation.
D) b and c
E) a, b, and c

Question 8

What are endogenous retroviruses?

A) RNA viruses that use reverse transcriptase to become part of the host cell's DNA
B) DNA viruses that use reverse transcriptase to become part of the host cell's DNA
C) RNA viruses that live inside a host
D) viral elements descended from retroviruses that have become a permanent part of a host's genome

Question 9

Which of the following is the correct order of the flow of energy?

A) lion → zebra → grass → sun
B) sun → grass → zebra → lion
C) sun → mycorrhizae → grass → zebra
D) sun → grass → mycorrhizae → intestinal bacteria

Question 10

Which of the following describes the relationship between a zebra and its intestinal bacteria and archaea?

A) commensalism
B) mutualism
C) predation
D) parasitism

Question 11

Based on Craig Benkman's work on coevolutionary interactions between crossbills and pine trees, which of the following would be expected?

A) A population where pines are not well-defended against crossbills likely has more squirrels than crossbills.
B) A population where pines are not well-defended against crossbills likely does not face a trade-off in defense against different predators.
C) A population where pines are not well-defended against crossbills likely has more crossbills than squirrels.
D) none of the above

Question 12

Which of the following is true regarding mobile genetic elements?

A) They may spread through populations even if they lower the fitness of individuals that carry them.
B) They will be eliminated from populations unless they are beneficial.
C) They do not affect protein coding regions so have no effect on fitness.
D) none of the above

Question 13

Based on Anderson and Johnson's conclusions regarding the evolution of tongue length in long-tongued flies, which of the following would be expected?

A) A study demonstrates that in populations with shorter tongues, other nectar sources have very long nectar tubes.
B) A behavioral study demonstrates that flies in populations with shorter average tongue lengths spend more time visiting other flowers than visiting Zaluzianskya flowers.
C) A study of available flowers in the population with the longest average tongue length reveals that no other nectar sources besides Zaluzianskya are available.
D) a and c
E) b and c

Question 14

How many segments of DNA from viruses does the human genome contain?

A) almost 20,000, the same number as the genes that encode proteins
B) almost 100,000, four times more than the genes that encode proteins
C) almost 5000, one-fourth the number of the genes that encode proteins
D) none; the human genome cannot contain viral DNA

Question 15

A complex geographic mosaic between red crossbill bill length and pinecone morphology has resulted in

A) diversifying coevolution.
B) Batesian mimicry.
C) coevolutionary alternation.
D) attenuated coevolution.

Question 16

Interactions in the web of life may act as an evolutionary force because

A) they may decrease the fitness of an organism.
B) they may increase the fitness of an organism.
C) they may increase or decrease the fitness of an organism.
D) they have no effect on the fitness of an organism.

Question 17

Which of the following, if it had occurred, would have likely meant that myxoma virus in Australia would have remained more virulent than it ultimately became?

A) The rabbit population crashed.
B) The rabbit population remained dense even after introduction of the virus.
C) Transmission opportunities were reduced.
D) none of the above

Question 18

The type of genetic material that can move around the genome is called

A) a mobile genetic element.
B) a mutagen.
C) a trans-acting element.
D) a pseudogene.

Question 19

A relationship that benefits one species while the other suffers a loss to fitness is

A) predation.
B) herbivory.
C) deceptive pollination.
D) a and b
E) a, b, and c

Question 20

Which of the following is true of Müllerian versus Batesian mimicry?

A) Under Müllerian mimicry, the two species converge on the same phenotype because the more similar they are, the more beneficial it is for both species involved.
B) Under Batesian mimicry, the model species should be under selective pressure to evolve away from its mimic phenotypically.
C) Under Batesian mimicry, the more similar the model is to the mimic, the less effective the warning coloration because predators will encounter some prey that are not toxic.
D) all of the above

Question 21

When Sandra Anderson and her colleagues studied fruit set of Rhabdothamnus solandri on the mainland and on the island, why was it important to measure fruit set when flowers were hand pollinated?

Question 22

Please describe three pieces of evidence that suggest that mitochondria are derived from free-living bacteria.

Question 23

Which is NOT true of positive frequency-dependent selection?

A) It is a type of selection in which the fitness of a genotype increases as it becomes more common.
B) It is a type of selection that decreases the frequency of alleles in a population.
C) It is a type of selection that increases the frequency of alleles in a population.
D) It is a type of selection in which the fitness of a genotype increases as it becomes more rare.

Question 24

Scott Carroll found that soapberry bug populations in Northern Australia had longer beaks than those in eastern Australia, even though both populations lived on the invasive balloon vine. What is an explanation for these differences?

Question 25

Why might we expect vertically transmitted endosymbionts to have smaller genomes than their free-living relatives?

Question 26

Imagine that parasite pressure is similarly high across Drosophila melanogaster's range, but different geographic areas differ in the amount of food typically available (high food versus low food). In what regions is higher resistance to parasitism likely, and why?

Question 27

Which of the following is true regarding the evolution of photosynthetic organisms?

A) Photosynthesis in green algae likely evolved from primary endosymbiosis of a photosynthetic bacteria.
B) Photosynthetic protozoans likely evolved from secondary endosymbiosis of a photosynthetic red algae.
C) A lineage of photosynthetic green algae evolved into land plants.
D) all of the above
E) none of the above

Question 28

How might the mutualism between ants and flowering plants boost the diversity of plants?

A) Ants benefit from fleshy elaiosomes on seeds.
B) The plant seed is protected from herbivores after being discarded in an ant nest.
C) Plants grow in a small range around ant colonies, geographically isolated from other plant populations.
D) b and c
E) a, b, and c

Question 29

Please explain why most scientists now accept the idea that the most recent common ancestor of eukaryotes likely possessed mitochondria.

Question 30

Describe how parasites may exert negative frequency-dependent selection on their hosts.

Question 31

What have scientists discovered about the aster leafhopper endosymbionts, Nasuia and Sulcia?

A) Nasuia and Sulcia can live outside of aster leafhoppers.
B) Nasuia and Sulcia produce amino acids that are not found in the sap of the host plant, but that are needed by the leafhopper.
C) Nasuia and Sulcia have lost most of the genes required for free-living bacteria to survive.
D) a and b
E) b and c

Question 32

Considering potential trade-offs between replication within hosts and transmission between hosts, would you expect parasites/pathogens to evolve to be more virulent if they are transmitted vertically (parent to offspring through reproduction) or horizontally (individual to individual)? Explain.

Question 33

Explain how endogenous retroviruses and mobile genetic elements have coevolved with their host genomes.

Question 34

Are mobile genetic elements always parasitic?

A) Yes; they always cause harm to the host.
B) Yes; when they are passed from generation to generation, they become parasitic within the population.
C) No; they can evolve to help hosts fight off disease.
D) No; they can evolve to be mutualistic.

Question 35

Which of the following best explains why rabbit myxoma virus in Australia became less virulent over time?

A) Opportunities for pathogen transmission decreased.
B) Infected rabbits lived longer.
C) More virulent strains replicated less within the host.
D) a and b
E) a and c

Question 36

Describe how Heather Henter was able to show that parasitism success in wasps was a heritable trait that varied in the population.

Question 37

You are studying virulence evolution in a virus that infects two different populations of elephants. One of the elephant populations is characterized by large population size and high density, while the other is smaller and much less dense. How might these differences influence the evolution of virulence in the pathogen?

Question 38

The stability of mutualisms is sometimes described as being "on a knife edge," with the possibility of shifting to an antagonistic, rather than a mutually beneficial, interaction. Using yucca moths as an example, explain why this is the case.

Question 39

Why might higher tolerance for TTX be more advantageous for garter snakes in some environments than in others?