Answer:
The name “amino acid” is derived from the amino group and carboxyl-acid-group in their basic structure. There are 21 amino acids present in proteins, each with a specific R group or side chainAll organisms have different essential amino acids based on their physiology.
The answer is polygenic inheritance.
Many physical characters (traits) depend on many different factors, each of which is determined by different genes. This is called polygenic inheritance.
For example, the color of the skin in humans. The color of the skin results from the interactions of several factors determined by different pairs of genes:-Certain genes could affect the metabolism of skin melanocytes.-Other genes can determine the distribution of melanin in the thickness of the skin.-Some genes could determine the relative amounts of each of the two possible types of melanin.-Others may affect the production of certain hormones involved in the activity of melanocytes.
Axon: the messenger cell that carries the command to contract muscles.