The McDonald-Kreitman test is an important tool in molecular evolutionary analysis. What is this test, and what kinds of insights can it provide?
What will be an ideal response?
The test compares synonymous and nonsynonymous sites in gene-coding regions. If the nonsynonymous : synonymous substitution ratio within species is the same as that between species, then the substitutions are likely to be neutral. If the ratios differ, natural selection is likely to have been responsible by favoring certain substitutions over others. Insights the test provides include identifying genes on which natural selection may be acting for further study, and testing for neutrality for population genetic analyses that assume or require neutrality.
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Where in the body does the latent, non infectious, non replicating form of the herpes simplex virus persist?
A. Motor neurons B. Red blood cells C. Cranial nerves D. Sensory nerves
What type of response is most associated with the brain sensing a cold environment? a. Decrease in blood flow to the skin
b. Heart rate decreasing. c. Increased respiration. d. Sweat glands increase their output. e. Increase in blood flow to the skin.
Which of the following is NOT an example of
gene flow?
a. several chimpanzees migrate from their colony to join another one close by b. spores from a mushroom are carried by the wind thousands of miles c. wild cherries are eaten by a migrating bird and the seeds released many miles away d. a small group of humans left Africa about 100,000 years ago and established new colonies in the middle East and Europe e. all of these are examples of gene flow
When does a chromosome go from one chromatid to two sister chromatids?
A. during the G1 phase of interphase B. during the G2 phase of interphase C. during the S phase of interphase D. during mitosis E. during cytokinesis