Which of the following innovations merits birds being a separate class?
a. wings d. metabolic rate and dry skin
b. metabolic rate e. wings, flight and metabolic rate
c. wings and flight
E
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One mole of a substance contains 6.02 x 1023 molecules. The atomic number of Li is 3 and the atomic mass is approximately 7. If you have three moles of Li, how many grams does it weigh?
A. 9 B. 21 C. 7 x 6.02 x 1023 D. 3 x 6.02 x 1023
Oncogenes are ____ to ____
a. dominant; proto-oncogenes b. recessive; proto-oncogenes c. incompletely dominant; proto-oncogenes d. dominant; tumor suppressor genes e. recessive; tumor suppressor genes
The unique feature of HeLa cells that make them important for research is that they are
a. identical to all other human cells. b. immortal cells and will grow in culture. c. limited in growth cycles. d. identical to stem cells. e. cannot propagate.
The primary producers for hydrothermal vent ecosystems are
A. chemoautotrophs. B. chemoheterotrophs. C. phytoplankton. D. cyanobacteria. E. algae.