what is genetic

Genetics is the scientific study of genes and heredity, which involves how certain qualities or traits are passed from parents to offspring as a result of changes in DNA sequence. A gene is a segment of DNA that contains instructions for building one or more molecules that help the body work. DNA is shaped like a corkscrew-twisted ladder, called a double helix, and the sequences of its bases provide the instructions for building molecules, most of which are proteins. Humans have approximately 20,000 genes. All of an organism’s genetic material, including its genes and other elements that control the activity of those genes, is its genome. In human, plant, and animal cells, the genome is housed in a structure called the nucleus. Chromosomes are tightly wrapped together structures that contain DNA inside each cell, and every normal cell has 23 pairs of chromosomes (for a total of 46) . Genes are passed from parents to offspring and contain the information needed to specify physical and biological traits. Understanding genetic factors and genetic disorders is important in learning more about promoting health and preventing disease.