Close to ________ percent of all childbirths in the U.S. occur out of wedlock

During the second month of pregnancy, the embryo

A) can be irritated by sounds. B) has rapid eye movements. C) responds to touch. D) shields its eyes in response to light.

In vertebrate animals, aspects of body differentiation are controlled by an interrelated group of genes called _______ genes

a. HOM. b. HOX. c. Phylogenic genes. d. None of the above.