Approximately ________ years ago, atmospheric oxygen reached its current concentration
(i.e., ~21 percent)
a. 100–500 million
b. 600–900 million
c. 1–2 billion
d. >2 billion
Answer: B
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Which of the following type of reversible enzyme inhibitor binds to a site distinct from the substrate active site?
A. competitive B. uncompetitive C. mixed D. uncompetitive and mixed E. competitive, uncompetitive, and mixed
Magnesium has 12 protons. How many electrons are
in its second energy level? a. 2 b. 4 c. 6 d. 8 e. 10
If a person's blood pressure is 120/70, the 70 refers to the pressure
A) during relaxation of the heart. B) during contraction of both ventricles. C) lowering between contractions. D) during contraction of the left ventricle only. E) during contraction of the vena cava.
For which of the following would growth on blood agar be a good diagnostic tool?
a. streptococci b. staphylococci c. all Gram-positive cocci d. enterococci