A paleontologist estimates that when a particular rock formed, it contained 12 mg of the radioactive isotope
potassium-40, which has a half-life of 1.25 billion years. The rock now contains 3 mg of the isotope. About how old is the
rock?
a. 2.5 billion years
b. 5.0 billion years
c. 1.25 billion years
d. 0.3 billion years
e. 0.4 billion years
ANSWER: a
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Extinction is an example of a ____
a. microevolutionary change b. macroevolutionary change c. natural selection d. Mendelian genetics e. "hopeful monster"
The production of pollen, seeds, and flowers attributed to the widespread distribution of angiosperms. Why is the production of pollen an advantage?
A. It allows fertilization in the absence of water. B. It allows fertilization in moist areas. C. It promotes pollination. D. It is necessary for sexual reproduction. E. It protects and nourishes the embryo.
The white blood cells that are central to adaptive
immunity are types of a. neutrophils. b. macrophages. c. mast cells. d. eosinophils. e. lymphocytes.
________ is when one species splits into two species or when one species transforms into another over time.
A. Convergent evolution B. Speciation C. Both reproductive isolation and speciation are correct. D. Reproductive isolation E. The founder effect