In Pavlov's famous experiment, what was used as the US?

A sleep disorder characterized by difficulty in falling asleep or remaining asleep throughout the night is ______

a. apnea c. cataplexy b. narcolepsy d. insomnia

Characteristics that vary on a continuum among people, such as height, weight, intelligence, and personality, are due to

A) dominant–recessive relationships. B) polygenic inheritance. C) incomplete dominance. D) genomic imprinting.