What is the basic unit of heredity?

The basic unit of heredity is a gene. Genes are specific sequences of nucleotides that encode the information necessary for the development and functioning of organisms. They serve as instructions for making proteins, which coordinate the various functions within living cells and contribute to an individual's traits.

Genes are located on chromosomes, which are structures composed of DNA and proteins that package the genetic material. While chromosomes contain many genes and are important for the organization and distribution of genetic information during cell division, they are not the fundamental units of heredity themselves.

Proteins, although crucial for many cellular processes and functions, are the end products of gene expression rather than the units of heredity. Nucleotides are the building blocks of DNA and RNA, but they do not convey heredity on their own; rather, they combine to form the genes that carry heritable information.

Thus, the identification of a gene as the fundamental unit of heredity encapsulates its role in storing and transmitting genetic information from one generation to the next, establishing the traits that define organisms.