Q: Exposure to what can increase the amount of pigment in the skin and make it appear darker? Choices: - gamma rays - sunlight - nuclear radiation - ultraviolet radiation A:
ultraviolet radiation

Q: What distinctive configuration of dna demonstrates the base-pairing nature of the bases? Choices: - single helix - double loop - triple helix - double helix A:
double helix

Q: Mammals have a number of kinds of thermoreceptors, each specific for a particular what? Choices: - electrical range - oxygen range - weight range - temperature range A:
temperature range

Q: By allowing blood levels of a hormone to be regulated within a narrow range, feedback loops contribute to maintaining what state? Choices: - hypothesis - hibernation - consciousness - homeostasis A:
homeostasis