The atmosphere of the early Earth is currently thought to have contained:a
carbon dioxide, water, oxygen, nitrogen, and hydrogen.
b. carbon dioxide, water, carbon monoxide, hydrogen, and nitrogen.
c. carbon dioxide, carbon monoxide, water, hydrogen, and nitric oxide.
d. carbon dioxide, ozone, nitric oxide, water, and hydrogen sulfide.
e. methane, water, ammonia, nitrogen, and oxygen.
B
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Which of the following is an example of a palindromic DNA sequence?
A. 5' - ATCGAC - 3' 3' - TAGCAG - 5' B. 5' - ATCATC - 3' 3' - ATCATC - 5' C. 5' - GCCGCC - 3' 3' - CGGCGG - 5' D. 5' - CTGCAG - 3' 3' - GACGTC - 5'
All vertebrates have _____
a. an open circulatory system c. lungs b. a two-chambered heart d. none of these
Which statement is NOT true concerning natural selection?
A. Natural selection acts on an individual's phenotype as it interacts with the environment. B. Natural selection has a strong effect on non-heritable traits. C. Reproduction plays an important role in the process of natural selection. D. Darwin popularized the term by contrasting it with artificial selection, or selective breeding.
When you need to go to a hospital for a surgery, you should ________
A) go to a hospital that is known to have success in treating your medical condition B) trust the nurses and doctors there because medical errors in hospitals are very rare C) pick the nearest hospital for convenience D) relax and try to avoid asking questions