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हिन्दी — Read in HindiBiology in news
Biology as it reaches the news: DNA, RNA and proteins, cells, evolution and fossils, animal behaviour, the brain, immunity and ageing. Prelims has asked how plant and animal cells differ and what B cells and T cells do in the body.
Foundation note: Dominant and recessive alleles
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DNA replication
Copy link to DNA replicationPrelims and Mains
DNA replication is the copying of a cell's deoxyribonucleic acid (DNA) before the cell divides, and that copying is mechanical work.
- The two strands pair adenine with thymine and guanine with cytosine, so each is a template for the other.
- The two strands are wound around each other and have to be pulled apart before either can be read: helicase spends adenosine triphosphate (ATP) to split the double helix, opening a Y shaped replication fork.
- Topoisomerases release the twisting building ahead of the fork.
What changed
19 Aug 2026BriefThe study found a molecular safety catch that keeps the copying apparatus inactive until a chemical signal releases it. The Hindu, 19 Aug 2026: Helicase, the enzyme that unzips DNA (opens in a new tab)
Also filed elsewhere
- Epigenetics · on Genomics, gene editing and cell therapy
Epigenetics is heritable change in how active a gene is, without any change to the DNA sequence itself.