Molecular Structure
DNA (Deoxyribonucleic Acid) consists of a double helix structure formed by two strands of nucleotides. Each nucleotide contains a sugar molecule (deoxyribose), a phosphate group, and one of four nitrogen-containing bases: adenine (A), thymine (T), guanine (G), or cytosine (C). These bases pair specifically - A with T and G with C - held together by hydrogen bonds. The complete human genome contains approximately 3 billion base pairs organized into 23 pairs of chromosomes.
Genetic Information Storage
DNA serves as the blueprint for life, storing genetic information through specific sequences of base pairs. These sequences form genes that provide instructions for protein synthesis and cellular function. The human genome contains roughly 20,000 protein-coding genes, though these comprise only about 2% of total DNA. Non-coding regions, once called "junk DNA," play crucial roles in gene regulation and other vital functions.
Replication and Inheritance
During cell division, DNA replicates through a semi-conservative process where each strand serves as a template for a new complementary strand. This ensures accurate transmission of genetic information to daughter cells. DNA repair mechanisms correct errors during replication, though some mutations occur naturally. These genetic variations contribute to diversity and evolution, while also potentially causing inherited diseases.Shutdown123