The trophoblast cells of the blastocyst form the ________, which extends elaborate villi into the blood-filled sinusoids of the uterine wall
A) allantois B) chorion C) yolk sac D) amnion
Answer: B
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In a fetus, the umbilical arteries arise from the renal arteries.
Answer the following statement true (T) or false (F)
Which of the following functional groups is the phosphate group?
A) -NH2 B) -PO4 C) -COOH D) -SH E) -OH
The partial pressure of oxygen in atmospheric air at sea level is
A) greater than the partial pressure of oxygen in atmospheric air at the top of Mt. Everest. B) less than the partial pressure of oxygen in atmospheric air at the top of Mt. Everest. C) equal to the partial pressure of oxygen in atmospheric air at the top of Mt. Everest. D) equal to the sum of partial pressures from carbon dioxide and nitrogen. E) equal to the partial pressure of carbon dioxide in atmospheric air at the top of Mt. Everest.
One of the main differences between a somatic reflex and autonomic reflex is the type of effectors that are activated. The effectors in somatic reflexes are _____, while the effectors in autonomic reflexes are _____
a) skeletal muscles; smooth muscle, cardiac muscle, and glands b) striated muscles; smooth muscle and glands c) skeletal muscles and glands; smooth muscle and cardiac muscle d) glands; skeletal muscles, smooth muscle, and cardiac muscle e) skeletal muscles; smooth muscle only