Animals require certain amino acids on their diet, an amino acid that is referred to as nonessential would be best described as one is less important than the essential amino acid, 2 can be made by the animal's body from other substances, 3 is not used by the animal in biosynthesis, 3 must be ingested in the diet, 4 is not found in many proteins

The answer is 2 can be made by the animal's body from other substances.

Both essential and nonessential amino acids have essential roles in the organism. Nonessential amino acids got their name because they are not an essential part of the diet. The main difference between these two groups of amino acid is that essential amino acids cannot be made by the animal's body and must be ingested in the diet unlike the nonessential amino acid which can be made by the animal's body.