1|Page
Evolutionary Biology Unit 1 (Clemson
University) 2026 Actual Questions
And Answers
Three steps in which evolution occurs - correct-answer -Acting on variation,
sorting via chance and selection, proportion of variants differs between
generations
Receptor on immune cells that HIV looks for - correct-answer -CD4
How do we track HIV's course of infection? - correct-answer -CD4 T-cell count;
becomes AIDS when too many of these are lost
Why does HIV mutate rapidly? - correct-answer -reverse transcriptase lacks
proofreading machinery, HIV has a short generation cycle
Why do we use "drug cocktails" to combat HIV? - correct-answer -The longer a
virus is exposed to a drug, the more time for selection and therefore resistance to
occur.
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Which of the following characteristics of the env gene (gp120 protein) give an
evolutionary advantage to the HIV virus following infection of a human host? -
correct-answer -High mutation rate results in considerable antigenic drift,
effectively staying one step ahead of host immune response. (This shows that HIV
can evolve against the host's immune system as well as drugs)
Which of the following inferences made from phylogenetic analyses of the nurse's
and patient's HIV sequences from the RT gene (reverse transcriptase) allowed for
the conclusion that the nurse was infected by the patient's HIV virus, rather than
the other way around. - correct-answer -Virus sequences from the victim (nurse)
were nested within the larger clade of sequences from the patient.
In the article, "The selective advantage of crypsis in mice," which evolutionary
process do the authors hypothesize is primarily shaping coat color in mice; which
statement best describes their hypothesis? - correct-answer -natural selection;
crypsis in mice increases chances of survival by reducing predation from visual
predators
New insights on Darwin-Wallace theory - correct-answer -Individual selection as
opposed to species, gradual change, organisms evolve in response to
environment, sexual selection, new species emerge from selection
Evolutionary Biology Unit 1 (Clemson
University) 2026 Actual Questions
And Answers
Three steps in which evolution occurs - correct-answer -Acting on variation,
sorting via chance and selection, proportion of variants differs between
generations
Receptor on immune cells that HIV looks for - correct-answer -CD4
How do we track HIV's course of infection? - correct-answer -CD4 T-cell count;
becomes AIDS when too many of these are lost
Why does HIV mutate rapidly? - correct-answer -reverse transcriptase lacks
proofreading machinery, HIV has a short generation cycle
Why do we use "drug cocktails" to combat HIV? - correct-answer -The longer a
virus is exposed to a drug, the more time for selection and therefore resistance to
occur.
, 2|Page
Which of the following characteristics of the env gene (gp120 protein) give an
evolutionary advantage to the HIV virus following infection of a human host? -
correct-answer -High mutation rate results in considerable antigenic drift,
effectively staying one step ahead of host immune response. (This shows that HIV
can evolve against the host's immune system as well as drugs)
Which of the following inferences made from phylogenetic analyses of the nurse's
and patient's HIV sequences from the RT gene (reverse transcriptase) allowed for
the conclusion that the nurse was infected by the patient's HIV virus, rather than
the other way around. - correct-answer -Virus sequences from the victim (nurse)
were nested within the larger clade of sequences from the patient.
In the article, "The selective advantage of crypsis in mice," which evolutionary
process do the authors hypothesize is primarily shaping coat color in mice; which
statement best describes their hypothesis? - correct-answer -natural selection;
crypsis in mice increases chances of survival by reducing predation from visual
predators
New insights on Darwin-Wallace theory - correct-answer -Individual selection as
opposed to species, gradual change, organisms evolve in response to
environment, sexual selection, new species emerge from selection
