X inactivation occurs
a. at birth.
b. at the beginning of the second trimester.
c. after the first cleavages of the zygote.
d. at the moment of conception.
e. randomly depending on the individual.
C
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A tariff is a
a. tax on exports. b. penalty imposed on exporters who export a greater quantity than the quota allows. c. penalty imposed on importers who import a greater quantity than the quota allows. d. tax on imports.
A friend of yours is wondering about the differences between the words orientation and navigation when these two terms are used in descriptions of bird migrations. Since you have studied and know something about animal behavior, what do you tell your friend?
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Assume that in a Hardy-Weinberg population, 9% of the individuals are of the homozygous recessive phenotype. What percentage are homozygous dominant?
A) 51% B) 9% C) 91% D) 49%