What is the basic unit of heredity?

• A. Chromosome
• B. Gene
• C. DNA
• D. RNA

Answer: (B)

The basic unit of heredity is a gene. Genes are segments of DNA that contain the instructions for building and maintaining an organism's cells, and they play a fundamental role in inheritance. Each gene encodes a specific protein or functional RNA, which ultimately influences the organism's traits.

While chromosomes consist of tightly coiled DNA and contain many genes, they are not the smallest unit of heredity. DNA is the molecule that carries genetic information but is made up of multiple genes; thus, it does not represent the basic unit of heredity by itself. RNA, while involved in the expression of genes and the synthesis of proteins, is not a hereditary unit. Therefore, the gene is correctly identified as the fundamental unit of heredity, responsible for transmitting traits from one generation to the next through inheritance.