What type of molecule crosses the blood-brain barrier freely?
a. lipid soluble molecules
b. glucose
c. proteins
d. water soluble vitamins
e. amino acids
ANSWER: a
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The white matter differs from gray matter in that ____
a. white matter is found in the brain, and gray matter is found in the spinal cord b. white matter consists of bundles of myelin-sheathed axons, and gray matter consists of cell bodies, dendrites, and neuroglial cells c. white matter transmits sensory information, and gray matter transmits motor information white matter consists of bundles of myelin-sheathed axons, and gray matter consists of cell bodies, dendrites, and neuroglial cells d. white matter is associated with the sympathetic nervous system, and gray matter is associated with the parasympathetic nervous system e. white matter contains mostly interneuronal cell bodies and grey matter does not
Ferns possess all of the following EXCEPT:
a. cuticles. b. embryos. c. seeds. d. roots. e. leaves.
A breeder of cattle has a herd of white cows and a roan bull. Hair color in this breed is controlled by an incompletely dominant gene. The two homozygous forms are either red or white, and the heterozygous is roan. What colors of calves are expected and in what proportions?
A. All white B. All red C. 1/2 white, 1/2 roan D. 1 white, 2 roan, 1 red E. 1/2 white, 1/2 red
Which one of the following is considered to be an important plant hormone that helps plants cope with environmental stresses?
A. abscisic acid B. auxins C. ethylene D. cytokinins E. prostaglandins