All amino acids have a similar structure. which component is responsible for the differences in the 20 amino acids

a: the carboxlyic acid

b: the r group

c: the central form

d: the amine group

How does pregnancy begin? a) a placenta forms in the uterus b) a sperm reaches an egg in the fallopian tubec) the blastocyst differentiates into two cell types d) contractions begin in the uterine wallapex

The leopard frog and the pickerel frog are two closely related species. in areas where their ranges overlap, the frogs will remain separate species if they

Which part of the cell is affected by the movement of molecules through diffusion, osmosis and active transport?