The chief inhibitory neurotransmitter in the brain is and the chief excitatory neurotransmitter is

Twin boys have girlfriends one of the couples have a baby would the dna of the lil baby be the same as the couples dna bc the boys are identical twins

Acell in the human nervous system whose primary function is to form myelin and the blood-brain barrier, respond to injury, remove debris, and enhance learning and memory is called a(n) cell.

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.