CBSE Class 9 Answered

Hair strands and fingernails are made up primarily of dead cells that are ejected from the body
Hair grows when cells gather at the root of each hair follicle and are pushed upward by more cells. Once the cells are pushed up, they no longer receive nourishment and go through a process called keratinization, which transforms them into a hard protein. The hair you see is a combination of keratin and dead cells that have been expelled by your body.

Fingernail growth is very similar to hair growth, except the cells are pushed into plates instead of strands. They are created from dead cells that build up and are converted into keratin, just like hair.