What are the four most abundant elements found in living systems?
a. nitrogen, carbon, sulfur, and oxygen
b. hydrogen, oxygen, nitrogen, and carbon
c. magnesium, calcium, iron, and zinc
d. hydrogen, oxygen, calcium, and nitrogen
e. hydrogen, oxygen, nitrogen, and carbon dioxide
Answer: b. hydrogen, oxygen, nitrogen, and carbon
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How is the bond in F2 different from the bond in KCl?
A. F2 is covalent and KCl is ionic B. F2 and KCl are both ionic C. F2 is ionic and KCl is covalent
Which of the following statements are true regarding the secondary immune response? Select all correct choices
A. It occurs more slowly than the primary immune response. B. It occurs faster than the primary immune response. C. It produces more antibodies than the primary immune response. D. It produces fewer antibodies than the primary immune response.
A human normally has how many vertebrae?
A. 33 B. 17 C. 12 D. 45
Factors that contribute to difficulty in eliminating fungal infections via the body's defenses include
A) the capsules of some fungi resist phagocytosis. B) many fungi are resistant to cell mediated immune responses. C) many pathogenic fungi produce leukocidins. D) both resistance to phagocytosis and cell mediated immunity. E) many pathogenic fungi are resistant to the action of complement.