DNA typically consists of two strands. These strands twist together to form the iconic double helix structure, first described by James Watson and Francis Crick in 1953.

Core Structure

In its standard biological form, DNA is a double-stranded molecule made of two polynucleotide chains running in opposite directions, known as antiparallel. Each strand serves as a template for the other during replication, ensuring genetic information is accurately copied. Nucleotides—building blocks with a sugar, phosphate, and one of four bases (A, T, C, G)—link to form these strands, with bases pairing specifically: adenine (A) with thymine (T), and cytosine (C) with guanine (G).

Rare Variations

While double-stranded DNA dominates in most cells, researchers have observed four-stranded structures called G-quadruplexes in specific genomic regions, especially guanine-rich sequences. These are not the norm and appear in contexts like telomeres or cancer-related studies, but they don't redefine DNA's baseline as having more than two strands. Single-stranded DNA occurs transiently during processes like replication or in some viruses.

Common Misconceptions

Claims of humans once having "12 active strands" circulate in pseudoscience forums but lack evidence; human DNA remains double-stranded with 20,000-25,000 genes. RNA, by contrast, is usually single-stranded, highlighting a key nucleic acid difference.

Why Two Strands Matter

The double helix provides stability and redundancy, protecting genetic data from damage while enabling precise duplication for cell division. This design underpins heredity across life forms, from bacteria to humans.

TL;DR: DNA has two strands in its standard form. Information gathered from public forums or data available on the internet and portrayed here.