6 Which of the following contributes to genetic variability within a population?
1. genetic drift
II. gene flow
III. mutations
IV. non-random mating
OA. I, II, and Ill only
OB. I, II, III, and IV
OC. I and II only
OD. III and IV only

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

Give three examples of plant activities that are affected by circadian rhythms and natural fluctuations in the length of daylight?

What is the significance of the protein-lined pits? a. protein attracts other proteins needed for atp synthesis within the cell. b. protein-lined pits are able to transport one molecule at a time down the concentration gradient within the cell. c. the polarity of proteins allows other polar molecules to attach and be transported in the cell by transport channels. d. receptors within the pits allow ligands to fuse and be transported into the cell by endocytosis.