During the first emergence of life, the atmosphere was ____.

A. high in oxygen, high in carbon dioxide
B. high in hydrogen, low in oxygen
C. changing from anaerobic to aerobic
D. aerobic
E. high in oxygen, low in carbon dioxide


Answer: B

Biology & Microbiology

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Which of the following terms refers to all

species that live and interact in a specific area?

a. biosphere b. community c. ecosystem d. population e. niche

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An example of a one-way relationship in which one species benefits and another is directly hurt is ____

a. commensalism b. mutualism c. interspecific competition d. scramble competition e. parasitism

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Most important vertebrate features like the brain and sense organs are derived from the

A) cerebral cortex B) vertebrate discs C) meninges D) neural crest

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In humans, dental cavities form when Streptococcus mutans bacteria in the mouth hydrolyze sucrose. Which of the following is (are) the products of this reaction?

A) Glucose and galactose B) Glucose and fructose C) Starch D) Glycogen

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