Science and Technology › Basic science in news
Biology 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.
19 Aug 2026 · Prelims and Mains
DNA replication
Before a cell divides it must copy its deoxyribonucleic acid (DNA), and that copying is mechanical work: the two strands are wound around each other and have to be pulled apart before either can be read. The enzymes that do the pulling were the subject of a study reported in August.
Unwinding
Helicase spends adenosine triphosphate (ATP) to split the double helix
Fork
A Y shaped replication fork opens where the strands part
Strain
Topoisomerases release the twisting building ahead of the fork
Copying
Each parted strand templates a new partner strand
- The two strands pair adenine with thymine and guanine with cytosine, so each is a template for the other.
- The 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)
9 Aug 2026 · Prelims and Mains
Raygun and protein miniaturisation
A protein chain folds into helices, sheets and loops, and it is that shape, not the length of the chain, that does the work. Raygun, an artificial intelligence system built on protein language models, works in the room this leaves: it resizes or rewrites a protein at a chosen length while keeping it working.
- Six of eight shrunken fluorescent proteins still glowed, surviving more than forty coordinated edits where four or five uncoordinated ones killed fluorescence.
- They glow only dimly, so the method needs refinement.
- Gene therapy is the use in view: viral shells carrying genes into cells have a size limit many genes exceed.
7 Sep 2026 · Prelims and Mains
Peptides in concentrated sulphuric acid
Peptide bonds break by hydrolysis, which is why a strong acid normally destroys a protein. Certain peptides have nonetheless stayed stable for weeks in 98 per cent sulphuric acid, the first biological macromolecule found to manage it.
- Concentrated sulphuric acid holds almost no water, so little is there to hydrolyse the bonds.
- Nuclear magnetic resonance spectroscopy showed them folding into an omega loop, not helices or sheets.
- Venus's clouds of the acid may then not be too harsh for complex chemistry.
The Hindu, 7 Sep 2026: Sulphuric acid: not so deadly (opens in a new tab)
2 Sep 2026 · Prelims
Bird song
A song must reach its receiver through whatever lies between, so the habitat sets limits on what will carry, and the bird's own body size fixes the physical range of what it can produce. Sexual selection then acts on what wins a mate rather than on what keeps a bird alive, and pushes song towards elaboration. Those pressures shape a song, but they turn out not to decide it.
Simple motifs
- Flat whistles and slow trills
- Larger birds
- Birds signalling over long distances
- Tropical rainforests, where song must carry through dense vegetation
Complex motifs
- Small birds
- Birds signalling at close range
- Groups under intense sexual selection
- Temperate Europe and North America, with small territories and short breeding seasons
- Machine learning on recordings of more than 3,000 passerine species found that the world's bird songs are built from eight basic motifs.
- The recordings came from Xeno-canto, a citizen science audio library, and the eight motifs are three trills, three whistles, atonal chaotic notes and harmonic stacks.
- Which motifs a bird uses is decided mostly by its evolutionary history rather than by where it lives.
- What a lineage has already inherited limits what it can evolve next, so close relatives often carry the same solution even where they live far apart.
- Indian passerines such as the house crow (Corvus splendens) and the red-vented bulbul (Pycnonotus cafer) are Least Concern on the IUCN Red List.
Also filed elsewhere
- Epigenetics · on Genomics, gene editing and cell therapy
A gene is a stretch of DNA whose sequence of bases spells out one protein, and Mendel's rules have each of its two copies passed on unchanged and independently.