In squirrels, the gene for gray fur (G) is dominant over the gene for black fur (g). If 50% of a large litter of squirrels are gray, the parental cross that produced this litter was most likely:
A. GG x Gg
B. GG x GG
C. Gg x gg
D. gg x gg
If each parent contributes only one gene of its pair to the offspring, the parental genes of Gg x gg would produce the following offspring: Gg or gg. Gg would appear gray while gg would produce black fur. The first cross would produce only gray squirrels since one parent always gives a G, masking the g given by the other parent. The second cross only has G so all offspring would have to be gray, and the last cross would not produce any gray squirrels since there are no G.
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Yes, that is my dog and she can fly
Exam Details
While these questions do not fit the MCAT format (they have no related reading passages) they cover concepts one should understand in order to do well in the biological sciences portion of the MCAT.
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