quiz review
D - ANS-Human head lice and chimp lice belong to the same genus. Why did these two
lineages of lice diverge?
A. Host switching occurred
B. Humans slept with chimps
C. There was a new niche for the lice to fill D. This is a product of co-speciation,
B - ANS-We predicted human head and pubic lice lineages diverged from a common ancestor
less than 6 million years ago, on a hominin host. This is because humans lost their hair around
that time. DNA comparison suggests the most recent common ancestor of human head lice and
human pubic lice lived ~12 million years ago. What do you conclude?
A. Accept the co-speciation hypothesis. Divergence of these two lice lineages was driven by
host speciation.
B. Reject the new niche hypothesis. Divergence of these two lice lineages was not driven by
loss of body hair
C. Accept the new niche hypothesis. Divergence of these two lice lineages was driven by loss of
body hair
D. Reject the co-speciation hypothesis. Divergence of these two lice lineages was not driven by
host speciation.
A - ANS-We hypothesized that human body lice arose because humans started to wear
clothing, and this opened up another niche for parasite to exploit. What information would help
you test this hypothesis?
A. Identifying the most recent common ancestor of human head and body lice
B. The invention of the merkin
C. Knowing when humans diverged from chimps
D. DNA from public lice
D - ANS-An example of a plant parasite that derives energy from a living host cell is:
A. Rhizoctonia (brown patch); it is a necrotroph
B. Rhizoctonia (brown patch); it is a biotroph
C. Puccinia (crown rust); it is a necrotroph D. Puccinia (crown rust): it is a biotroph
A - ANS-A plant parasite that is transmitted by a vector is:
A. Dutch elm disease
B. Panama disease
C. Potato late blight (Phytophthora infestans)
D. Chestnut blight (Cryphonectria parasitica)
B - ANS-Planting more diverse crops can lower disease transmission by:
A. increasing biomass yields
, B. adding non-target hosts
C. adding parasite diversity
D. altering the outcome of competition between hosts
B - ANS-The following parasite species are both deemed highly host specific by a researcher.
Which parasite species do you have the most confidence in their measure of high host
specificity?
A. Parasite 1: subject to a single survey in which it was found in one host species at one
location
B. Parasite 2: regularly reported from several populations of the same host species over a large
geographic area
C. Parasite 3: multiple surveys indicate that parasite was recovered from the same host species
in one host population.
D. Parasite 4: several reports from populations of different host species over a large geographic
area
B - ANS-Over evolutionary time, (a)______________ suggests host and parasite phylogenies
will become congruent and yields high levels of host specificity . However (b) ______________
may lead to a decrease in host specificity.
A. Host switching; Co-speciation
B. Fahrenholz's Rule; Host switching
C. Host-sharing; compatibility filters
D. Co-speciation; Fahrenholz's Rule
C - ANS-Encounter and compatibility filters can drive parasite transmission to certain host
species. Consider a newly invading host species (this host is not native to the area and consider
an invasive species) in an ecosystem. This parasite species does not growth well in this
new/invading host species, but it is very similar to the native host species. Which filter will a
parasite change and how?
A. Increase encounter
B. Decrease compatibility
C. Decrease encounter
D. Increase compatibility
A - ANS-A directly transmitted parasite that cannot survive for long in the environment should
evolve what level of virulence?
A. Low virulence
B. High virulence
AC - ANS-Based on the math model we saw in class, which of the following scenarios may
lower parasite virulence? Note you can pick more than one answer.
A. Decreased natural host mortality
B. Decreased transmission
C. Increased transmission rate
D - ANS-Human head lice and chimp lice belong to the same genus. Why did these two
lineages of lice diverge?
A. Host switching occurred
B. Humans slept with chimps
C. There was a new niche for the lice to fill D. This is a product of co-speciation,
B - ANS-We predicted human head and pubic lice lineages diverged from a common ancestor
less than 6 million years ago, on a hominin host. This is because humans lost their hair around
that time. DNA comparison suggests the most recent common ancestor of human head lice and
human pubic lice lived ~12 million years ago. What do you conclude?
A. Accept the co-speciation hypothesis. Divergence of these two lice lineages was driven by
host speciation.
B. Reject the new niche hypothesis. Divergence of these two lice lineages was not driven by
loss of body hair
C. Accept the new niche hypothesis. Divergence of these two lice lineages was driven by loss of
body hair
D. Reject the co-speciation hypothesis. Divergence of these two lice lineages was not driven by
host speciation.
A - ANS-We hypothesized that human body lice arose because humans started to wear
clothing, and this opened up another niche for parasite to exploit. What information would help
you test this hypothesis?
A. Identifying the most recent common ancestor of human head and body lice
B. The invention of the merkin
C. Knowing when humans diverged from chimps
D. DNA from public lice
D - ANS-An example of a plant parasite that derives energy from a living host cell is:
A. Rhizoctonia (brown patch); it is a necrotroph
B. Rhizoctonia (brown patch); it is a biotroph
C. Puccinia (crown rust); it is a necrotroph D. Puccinia (crown rust): it is a biotroph
A - ANS-A plant parasite that is transmitted by a vector is:
A. Dutch elm disease
B. Panama disease
C. Potato late blight (Phytophthora infestans)
D. Chestnut blight (Cryphonectria parasitica)
B - ANS-Planting more diverse crops can lower disease transmission by:
A. increasing biomass yields
, B. adding non-target hosts
C. adding parasite diversity
D. altering the outcome of competition between hosts
B - ANS-The following parasite species are both deemed highly host specific by a researcher.
Which parasite species do you have the most confidence in their measure of high host
specificity?
A. Parasite 1: subject to a single survey in which it was found in one host species at one
location
B. Parasite 2: regularly reported from several populations of the same host species over a large
geographic area
C. Parasite 3: multiple surveys indicate that parasite was recovered from the same host species
in one host population.
D. Parasite 4: several reports from populations of different host species over a large geographic
area
B - ANS-Over evolutionary time, (a)______________ suggests host and parasite phylogenies
will become congruent and yields high levels of host specificity . However (b) ______________
may lead to a decrease in host specificity.
A. Host switching; Co-speciation
B. Fahrenholz's Rule; Host switching
C. Host-sharing; compatibility filters
D. Co-speciation; Fahrenholz's Rule
C - ANS-Encounter and compatibility filters can drive parasite transmission to certain host
species. Consider a newly invading host species (this host is not native to the area and consider
an invasive species) in an ecosystem. This parasite species does not growth well in this
new/invading host species, but it is very similar to the native host species. Which filter will a
parasite change and how?
A. Increase encounter
B. Decrease compatibility
C. Decrease encounter
D. Increase compatibility
A - ANS-A directly transmitted parasite that cannot survive for long in the environment should
evolve what level of virulence?
A. Low virulence
B. High virulence
AC - ANS-Based on the math model we saw in class, which of the following scenarios may
lower parasite virulence? Note you can pick more than one answer.
A. Decreased natural host mortality
B. Decreased transmission
C. Increased transmission rate
