It is the individual's environment that controls which parts of the genome are activated, according to the probabilistic epigenesis theory

Research on the extent to which adult communication helps children correct errors and take the next grammatical step forward shows that such techniques

A) are actually negative in outcome because children become overly frustrated. B) make no demonstrable difference in grammar development. C) are inconclusive in their impact. D) are dramatic in effect across cultures.

The amount of light entering the eye is regulated by the size of the

a. optic orbits. b. lens. c. sclera. d. pupil. e. conjunctiva.