9) oxygenated blood reaches the fetus through the __________.
a. umbilical vein
b. umbilical arteries
c. maternal vein
d. maternal arteries
e. placental sinus
10) a sperm count any lower than __________ million sperm per ml of semen is usually
associated with infertility (sterility).
a. 250 to 500
b. 200 to 250
c. 100 to 200
d. 50 to 100
e. 20 to 25
11) genes produce their products __________.
a. as their products are needed or not
b. at a steady rate all the time
c. only when the appropriate hormone is present
d. when the transcription activator is inhibited by an extracellular signal
12) with regard to the healing of a skin wound, macrophages ___________.
a. release histamine to increase blood flow to the area
b. produce and secrete collagenous fibers
c. phagocytize and digest tissue debris
d. stimulate epithelial cells to multiply
e. make capillaries more permeable allowing white blood cells to migrate into the area
13) which of the following are primarily responsible for maintaining the salinity