A pigeon learns to peck only at a red disk. It will not peck at an identical disk of any other color. This illustrates the concept of ___________

The cell membrane is formed by a single layer of lipid molecules

Indicate whether the statement is true or false.

Ramon sees a therapist because he is reliving a traumatic experience and has been trying to avoid reminders of it. The onset of his problem occurred three weeks ago, after he was brutally assaulted and robbed. The therapist would most likely diagnose Ramon with which disorder?

a. acute stress disorder c. generalized anxiety disorder b. posttraumatic stress disorder d. panic disorder