Hallucinogenic drugs, such as LSD, produce their effects via an action on the neurotransmitter

Monozygotic twins are also known as ______ twins

Fill in the blank with correct word

Investigations of animal behaviors indicate that ________

a. the actions of animals can be explained by instinct and by principles of operant conditioning alone. b. chimpanzees have a rudimentary sense of number and appear to have some sort of summing ability. c. humans are the only animals who can acquire behaviors from their parents. d. Many animals use species-specific languages to communicate.