What Is Genetics?

This post is the first in our miniseries on genetics. Stay tuned for more! Genetics is the study of genes and heredity—how traits are passed from parents to children through DNA. A gene is a segment of DNA that contains instructions for building one or more molecules that help the body work. Researchers estimate that humans have about 20,000 genes, which account for about 1 percent of our DNA. The remainder of the DNA plays a role in regulating genes, and scientists are researching other potential functions. DNA Details Credit: NIGMS. DNA is shaped like a twisted ladder, called a double helix. The two ladder rails are called backbones, and the rungs are pairs of four building blocks (adenine, thymine, guanine, and cytosine) called bases. The sequence of these bases provides the instructions for building molecules. The number of bases in a human gene varies from about 1,000 to 1 million. Nearly all the cells in our bodies contain a full copy of our DNA, and it’s stored in a structure called the nucleus. To enable DNA to fit inside the nucleus, it’s tightly wrapped around spool-like proteins called histones to form chromosomes. People typically have 23 pairs of chromosomes. The two chromosomes in each pair contain the same genes, but they may have different variants of those genes, in part because we generally inherit one chromosome in each pair from each parent. Variation and Health Most of your DNA is the same as that of everyone a...
Source: Biomedical Beat Blog - National Institute of General Medical Sciences - Category: Research Authors: Tags: Genes Common questions DNA Genetics Miniseries Genomics Source Type: blogs