What triggers new outbreaks of influenza after long periods of apparent immunity to the virus?
a. loss of all resistant individuals from the population
b. mutation of the influenza virus genome by UV exposure, which results in more virulent strains
c. antigenic shifts in the influenza genome, which generate hybrid viruses with surface proteins unrecognized by the immune system
d. none of the above
Answer: C
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In binary fission, one would expect the involvement of which of the following cytoskeletal proteins?
A) FtsZ B) MreB C) plaktin D) crescentin E) tubulin
In plants, the microtubules organizing centers are comprised of microtubules
a. True b. False
In mitosis,
a. the chromosome number is halved. b. the chromosome number is doubled. c. the chromosome number stays the same. d. the chromosome number may double or be halved depending on the species. e. gametes are formed in bacteria only
The situation in which an embryo produced as a
result of a mating between individuals of different species is incompatible with the mother and is subsequently aborted is an example of a. temporal isolation. b. hybrid inviability. c. mechanical isolation. d. gametic mortality. e. behavioral isolation.