Sperm live for up to days and can lie in wait for the ovum, which survives for day(s.

Punctuated equilibrium verses gradualism have long been contested as ways in which species evolve. choose the best evidence for gradualism.

What advantage does a crop that undergoes vegetative reproduction have over plants that start from the seed? 1points a they store nutrients. b they can travel farther. c they experience more genetic variation. d they only occur in high-resource environments.

What percentage of light hits earth's surface directly?