What are the “building blocks” of genetics and molecular medicine?
• A cell is the individual unit from which tissues of the body are formed • DNA is the double-stranded molecule that encodes genetic information in the nucleus of cells. A DNA strand is composed of four different nucleotides or base pairs (adenine, guanine, cytosine, and thymidine). It determines the structure, function and behavior of the cell. In animals and plants, long strands of DNA are arranged into structures called chromosomes • Genes are sometimes known as the physical unit of heredity. Genes are formed from DNA, carried on the chromosomes and are responsible for the inherited characteristics that distinguish one individual from another. Each human individual has an estimated 30,000 separate genes. • Chromosomes are the self-replicating genetic structures of cells. They contain the cellular DNA that bears in its nucleotide sequence the linear array of genes. • RNA is the single-stranded molecule that is transcribed from DNA and ultimately translated into a chain of amino acids
