DNA stands for deoxyribonucleic acid. It is the hereditary material found in humans and almost all other organisms. DNA contains the instructions that tell cells how to function and grow. It is organized into genes, which are segments of DNA that code for specific proteins.
DNA is a complex molecule composed of two long chains of nucleotides. Each nucleotide consists of a sugar, a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). The two chains of DNA are held together by hydrogen bonds between the bases, forming a double helix structure.
The sequence of these bases is what determines the genetic information encoded in DNA. For example, the sequence ATG codes for the start of a protein.
Examples of DNA's role:
- Directing protein synthesis: DNA provides the blueprint for building proteins, which are essential for a wide range of biological functions.
- Inheriting traits: DNA is passed down from parents to offspring, carrying genetic information that determines traits like eye color, hair color, and height.
- Evolution: DNA can mutate over time, introducing variations that drive evolution and the diversity of life.
Related terms:
- Gene: A segment of DNA that codes for a specific protein.
- Chromosome: A thread-like structure made up of DNA and proteins that carries genetic information.
- Genome: The complete set of DNA in an organism.
