A houseplant placed in a window grows toward the source of light because auxin
a. becomes more concentrated on the illuminated side of the plant.
b. becomes more concentrated in the roots of the plant.
c. becomes more concentrated on the nonilluminated side of the plant.
d. inhibits the growth of cells on the shady side, so the cells on the sunny side grow
faster.
e. does none of these.
Meninges
Choose the most appropriate answer.
a. integrates body position, motions, balance
b. in cnidarians; based on reflex pathways devoted to swimming and feeding
c. messages from here arouse the brain and maintain wakefulness
d. the cortical region that coordinates muscles required for speech
e. all parts of nerve cells outside the brain and spinal cord
f. acetylcholine is an example
g. reflex control center for breathing, heart rate, and blood pressure
h. axons of the central nervous system that are sheathed with fatty myelin
i. at top of the brainstem bordering the cerebral hemispheres; influences learning and
emotional behavior
j. motor neurons that are divided into sympathetic and parasympathetic divisions
k. membrane coverings over brain spinal cord