In rabbits black color B is dominant to brown b and full col

In rabbits, black color (B) is dominant to brown (b) and full color expression (C) is dominant to chinchilla (c). The genes controlling these traits are linked. In a cross of an individual heterozygous for both traits (BC/bc) and another that expresses both recessive traits (bc/bc), the following results are obtained: What two phenotypes represent the non-crossover gametes? Determine the map distance between the two genes.

Solution

Ans 1. Black full and brown chinchilla represent the noncross over gametes. These are the parent phenotype which involve no recombination. When there is no cross over, heterozygous parents will produce only two type of gametes BC / bc and homozygous parent will produce only one type of gametes. So, here parental progeny is non cross over gametes.

Ans 2. Map distance between 2 gene is given by =

Single cross over phenotype (recombination frequency)/ total progeny* 100

Total progeny = 100

Recombination frequency = 35

= 35/100 *100

= 35 centimorgan