# DBT JRF 2020 — Question 110

Exam: DBT JRF 2020 · Section: B · Topic: Genetics · Difficulty: Medium

## Question

A set of closely linked genetic markers present on a single chromosome, which are not easily separable by recombination and tend to be inherited together are termed as

## Options

- **A.** isotypes
- **B.** haplotypes
- **C.** allotypes
- **D.** alleles

## Answer

Option B

## Explanation

A haplotype is a set of closely linked genetic markers (SNPs, microsatellites) located on a single chromosome, inherited together as a unit with minimal recombination between them. The HapMap Project characterised haplotype blocks across the human genome — segments of tight linkage disequilibrium (LD) separated by recombination hotspots. Because markers within a haplotype block are not easily separated, genotyping a subset of tag SNPs can predict the genotype of all other SNPs in the block. This enables genome-wide association studies (GWAS) to be performed efficiently with fewer markers. The term derives from 'haploid' + 'genotype.' Common haplotype systems: MHC/HLA haplotypes (highly polymorphic, mediate transplant compatibility); mitochondrial haplotypes (matrilineal ancestry); Y-chromosome haplotypes (patrilineal).

Source: https://mypyqbuddy.com/questions/a-set-of-closely-linked-genetic-markers-present-6a05a8a02adafec470293286