The recombination frequency between the genes a and c is 5 % , b and c is 15 % , b and d is 9 % , a and b is…

The recombination frequency between the genes a and c is 5%, b and c is 15%, b and d is 9%, a and b is 20%, c and d is 24% and a and d is 29%. What will be the sequence of these genes on a linear chromosome?
  1. d,b,a,c
  2. a,b,c,d
  3. a,c,b,d
  4. a,d,b,c

Solution

The recombination frequency is directly proportional to the distance between genes, and the recomination values are used to locate the genes on a chromosome. Here, four genes a, b, c, and d are present with their recombination frequency of a - c = 5%, b – c = 15%, b - d = 9%, a – b = 20%, c – d = 24%, a – d = 29%.

The correct sequence of genes is a-c-b-d, and this is in accordance with the recombination frequency. 29% is the highest recombination frequency present between a and d, this signifies a and d are very far apart, and they are present at the endpoint. The distance between a and c is very less of 5%, which means they are very nearby and next to each other. Likewise, the distance between b and d is very less of 9%, which means they are very nearby and next to each other.

Asked in: NEET 2022 (Phase 1)

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