DNA and genes

In short: DNA carries the hereditary information in almost all living things. Genes are sections of DNA that contain the blueprint for proteins.

In more detail: DNA consists of four building blocks (bases): adenine, thymine, guanine and cytosine. A pairs with T, G with C. Two strands form the well-known double helix.

In detail

• Genome: The human genome has about 3 billion base pairs and around 20,000 protein-coding genes.
• Chromosomes: DNA is packed into chromosomes. Humans have 46, 23 from each parent.
• From gene to protein: DNA is transcribed into RNA, and the cell reads it into chains of amino acids.
• Mutations: Changes in DNA, often harmless, rarely beneficial or disease-causing.
• Relatedness: Humans are about 99.9 percent genetically identical (mitose-und-meiose).