# DBT JRF 2020 — Question 21

Exam: DBT JRF 2020 · Section: B · Topic: Bioinformatics · Difficulty: Hard

## Question

The sequence CGAATTTGG is matched globally with four sequences in a database. The sequence that will give the highest similarity score taking match =1, mismatch = 0 and gap penalty = minus 1 is

## Options

- **A.** CGTTTGG
- **B.** CGTATCG
- **C.** CGATTCG
- **D.** CAATGAG

## Answer

Option A

## Explanation

One centiMorgan (cM) is a unit of genetic distance defined as the chromosome length over which, on average, 1 recombination event (crossover) occurs per 100 meioses, resulting in a 1% recombination frequency. $1 \text{ cM} = 1\%$ recombination frequency (after statistical correction for double crossovers using Kosambi or Haldane mapping functions). Distances >50 cM are unlinked (independent assortment). In humans, 1 cM corresponds to approximately 1 Mb of physical DNA on average, but this varies greatly by chromosomal region and sex (females have higher recombination rates).

Source: https://mypyqbuddy.com/questions/the-sequence-cgaatttgg-is-matched-globally-with-four-6a05a8a02adafec47029322d