Which of the following is a morphine-like neurotransmitter that acts as a natural pain killer?
a. endorphin
b. acetylcholine
c. dopamine
d. epinephrine
a. endorphin
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An animal that undergoes physiological changes caused by an experimentor regulating environmental variables is said to have __________
Fill in the blank with correct word
Receptor-mediated endocytosis
A) is a type of secretion. B) imports target molecules after they bind to membrane proteins. C) does not require energy from the cell. D) can only move a substance down its concentration gradient. E) imports extracellular fluid, including all of its dissolved molecules.
Which of the following statements about brain size is true?
a. Elephants have a larger number of neurons in their brain than humans do. b. Octopods have a larger number of neurons in their brains than humans do. c. The neurons in human brains are larger than the neurons in other primates' brains. d. The brains of leaf-eating primates are larger than the brains of fruit-eating primates. e. The ratio of brain size to body size is larger in baleen whales than in dolphins.
Which of the following is NOT a type of glial cell found in the central nervous system?
a. oligodendrocytes b. astrocytes c. Schwann cells d. ependymal cells e. microglia