One critical requirement for life to arise on Earth was time for which to occur?
a. The salinity of the oceans to stabilize
b. The Earth's various climates to stabilize
c. Molecules to accumulate and react with one another
d. The atmospheric temperature to increase sufficiently
e. The ozone layer to form, so that the level of ultraviolet radiation was reduced
c
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Viruses are characterized by all of the following except
A. being specific to the hosts they infect. B. being acellular. C. being capable of independent reproduction. D. being found in every organism investigated so far.
Peroxisomes likely originated from endosymbiosis.
a. true b. false
You are a paleontologist trying to find fossils that represent intermediate forms in an evolutionary transition. Which of the following pieces of information could help you identify a geological formation for your search?
a. Based on the fossil record the evolutionary transition must have taken place 210 to 230 million years ago. b. Transitional fossils likely had long spines. c. The organisms' hard shells would have made fossilization likely. d. The transition is predicted to have taken place in shallow inland seas. e. A and D.
All of the following are similarities between HAV, HBV, and HCV, except
A. they all cause hepatitis. B. they are all RNA viruses. C. they all can have an incubation period of one month. D. they are all endemic in the U.S. E. there are diagnostic tests available to distinguish between them.