UPSC Prelims 2023 question on Microsatellite DNA

Short tandem repeats (STRs), also known as microsatellites, refers to a short segment of DNA, usually one to six or more base pairs in length, that is repeated multiple times in succession at a particular genomic location.

These DNA sequences are typically non-coding. The number of repeated segments within a microsatellite sequence often varies among people, which makes them useful as polymorphic markers for studying inheritance patterns in families or for creating a DNA fingerprint from crime scene samples.

On the basis of different repeat units, STRs can be classified into different types. Microsatellites were popularized in population genetics during the 1990s because as PCR (Polymerase Chain Reaction) became popular in laboratories researches, a microsatellite with a neutral evolutionary history makes it applicable in important genetic researches including studying evolutionary relationships among various species.

Hence option (a) — Studying the evolutionary relationships among various species of fauna — is the correct answer.