The human embryo's first blood cells arise in the
A) developing liver.
B) developing bone marrow.
C) yolk sac.
D) allantois.
Answer: C
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Which of the following is not a type of phagocyte?
A. Lymphocyte B. Kupffer cell C. Neutrophil D. Macrophage E. Monocyte
If fermentation pathways follow glycolysis, ____
a. CO2 will be one of the products as pyruvate is converted to lactate b. the two NADH molecules produced during glycolysis will (depending on the organism) be used to reduce pyruvate to either lactate or ethanol and CO2 c. ATP will be required to convert pyruvate to either lactate or ethanol and CO2 d. oxidative phosphorylation occurs either on the plasma membrane or on derivatives of the plasma membrane e. ATP will be required to convert lactate to pyruvate and CO2
Which one of the following features of Archaeopteryx clearly demonstrates that it was on the evolutionary line leading from dinosaurs to birds?
A. bony tail B. teeth C. egg-laying ability D. feathers E. claws on forelimbs
Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment
A) is isotonic to the protozoan. B) is hypotonic to the protozoan. C) contains a higher concentration of solutes than the protozoan. D) is hypertonic to the protozoan.