The stage of human fetal growth, in which cells begin to rapidly divide, follows fertilization of the egg.
a. infantile
b. fetal
c. embryonic
d. blastogenic

In order to clone adult animals, scientists typically begin with a(n)

Cell specialization occurs by the process ofa. reproductionb. differentiationc. maturationd. growth

The large increase in atmospheric carbon dioxide in the last 50 years most likely comes from a. an increase in cellular respiration b. increased decomposition by bacteria c. an increase in the burning of fossil fuels d. an increase in photosynthesis