2.13 :  遺伝物質

Within the human body, a vast network of trillions of cells functions cohesively. Typically, each cell contains a nucleus with 46 chromosomes,  a highly coiled structure made up of deoxyribonucleic acid, or DNA, the genetic material.

Genes are short sequences of DNA that act as fundamental units of heredity, encoding instructions for synthesizing proteins. These proteins are essential for numerous biological functions, including digesting food, cellular metabolism, fighting infections,  building muscle mass, and growth.

Of the 46 chromosomes, 22 pairs are autosomes, which govern most of the individual's physical traits, such as eye color and blood type.

The 23rd pair, the sex chromosomes, determines the individual's sex. Females possess two X chromosomes, while males have one X and one Y chromosome.

Both males and females pass on half of their chromosomes—22 autosomes and one sex chromosome, either X or Y—to their offspring, ensuring the accurate and prompt transfer of genetic material to the next generation.