Please, help me! If an organism needs to produce about 20 different amino acids, guess how many bases are needed to code for each amino acid. Do 1, 2, 3, or 4 bases code for each amino acid?

Astudent is looking through a microscope at some cells of an onion root tip. many of these cells are undergoing division since the root tip grows quickly and requires more cells. which cell most recently underwent metaphase? w x y z

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.

Which characteristics are typical of a human population in the postindustrial stage?