Large amounts of oxygen gas first appeared in Earth's atmosphere about ________ years ago
A) 500,000
B) 10 million
C) 2.7 billion
D) 3.5 billion
C
Biology & Microbiology
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The Panamanian golden frog is in decline from what specific threat?
A. a virus B. a fungus C. an introduced competitor D. a new road E. overharvesting
Biology & Microbiology
Using fetal DNA from the mother's blood for prenatal testing is a noninvasive procedure
a. True b. False Indicate whether the statement is true or false
Biology & Microbiology
The nodular, red, translucent surface material of a healing wound is called
A. soluble skin. B. irritated scab. C. granulation tissue. D. abscess.
Biology & Microbiology
Which form(s) of nitrogen is(are) unusable by plants?
a. ammonium b. nitrates c. nitrogen gas d. More than one of these answers is correct.
Biology & Microbiology