A human male is generally considered sterile if his ejaculation contains less than:
A) 100,000,000 sperm
B) 20,000,000 sperm
C) 100,000 sperm
D) 1,000 sperm
Ans: B) 20,000,000 sperm
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Using Figure 13.3, match the following:
1) Ganglion cells.
2) Bipolar cells.
3) Horizontal cell.
4) Amacrine cell.
5) Rod.
Binding of norepinephrine (NE) to an alpha-adrenergic receptor is usually excitatory, and binding to a beta-adrenergic receptor is usually inhibitory.
Answer the following statement true (T) or false (F)
A student is examining a microscope slide showing a cross section of the small intestine. She identifies some muscle tissue. What type is she looking at?
A. Skeletal B. Cardiac C. Smooth
When maintaining homeostasis, it is important to do all of the following EXCEPT
A) detect external conditions. B) control external conditions. C) generate compensatory responses to the changes. D) protect vital areas from damaging changes.