The "twisted ladder" shape of a DNA molecule results from Group of answer choices cytosine pairing with adenine. thymine pairing with uracil. adenine pairing with uracil. adenine pairing with thymine. cytosine pairing with thymine.

Ecologist have observed a sharp increase of sulfur dioxide in the air . what might be a possible consequence of excessive sulfur dioxide in the air ? a. acid rain b. ozone layer depletion c.ozone layer hole d.increase in sea levels

What causes darkening of the skin as melanin production increases

Which of the following statements most accurately describes convergent evolution? the process in which two similar species evolve separately from each other and share similar characteristics the process in which a single species evolves into two or more new species the process in which two entirely different species evolve in response to each other the process in which two different species evolve separately from each other but still share similar characteristics