Final answer:
The statement is false; the human body cannot produce all 20 amino acids. It synthesizes about 11 non-essential amino acids, while the remaining 9 essential amino acids must be obtained through the diet.
Step-by-step explanation:
The statement that the body produces the 20 amino acids that make up the hair is false. Humans use 20 standard amino acids to synthesize proteins, but not all of these can be produced by the body. The human body is capable of synthesizing about 11 of these amino acids, which are termed non-essential amino acids. However, there are 9 amino acids, known as essential amino acids, that the body cannot synthesize. These must be obtained through the diet. It's important to note that the body does not store excess amino acids, making daily intake vital. The essential amino acids are crucial for various metabolic processes, including the building and repair of tissues, such as hair.