A man witnessed an explosion in which a coworker died, and soon after, he lost his vision. Despite many neurological tests, doctors could not find any organic basis for the man's loss of eyesight. The man is most likely suffering from:

Sometimes the feedback from parents does not have the intended effect. One example of this is a phenomenon known as the __________________________________ ____________________________________ ______________________________ . This occurs in a three-stage process. For example, (1) a parent tells a child to do something unappealing; (2) the child responds by arguing, whining, or complaining excessively; (3) the parent gives in to stop the whining behavior. In effect, the parent has reinforced the whining—the child has learned that whining works to get out of unappealing tasks and will be more likely to whine next time.

Fill in the blank(s) with the appropriate word(s).

Twins who are genetically identical are known as ___________ twins

a. dizygotic c. dominant b. monozygotic d. recessive