Synaptic pruning a. is a normal part of brain development. b. ...

[bobypop]

Synaptic pruning
 
  a. is a normal part of brain development.
 b. is associated with mental retardation, and results in too few connections.
  c. results from insufficient amounts of neurotrophins.
 d. results from excess amounts of neurotrophins.

Question 2

The force of a movement is most directly controlled by
 
  a. the rate of motor neuron firing alone.
 b. recruitment of motor units alone.
 c. feedback from muscle spindles and recruitment.
 d. the rate of motor neuron firing and recruitment.

[kxciann]

Answer to Question 1

a

Answer to Question 2

d