The building blocks of protein are C. AMINO ACIDS.
Amino acids are made up of a center carbon atom bound positively to a charged amino group and a negatively charged carboxyl group and a side chain.
The primary structure of a protein is the sequence of an amino acids that are attached together by a peptide bond
The secondary structure of a protein, the polypeptide is folded through the mechanisms of amino acids rotating around bonds folding into a helix or a pleated sheet structure and stabilized by a hydrogen bond.
B. Because the environment can not supply for the food and caring of the animal species that is growing larger.
Only once because the DNA replication initiation is tightly linked to cell cycle progression,ensuring that replication occur only once per cycle
Aerobic respiration takes place in the mitochondria and requires oxygen and glucose, and produces carbon dioxide, water, and energy.
anaerobic respiration also produces energy and uses glucose but it produces less energy and does not require oxygen.