Please EXPLAIN in detail how you would answer this question

Please EXPLAIN in detail how you would answer this question.

In a species of Drosophila, genes q andrare found on the same chromosome 20 centimorgans apart. A cross was made between the following individuals What proportion of the offspring would you expect to have the wild-type phenotype (wild-type is denoted by the alleles and is dominant to the mutant alleles)? Select one: a. 0.20 b 0.10 C. 0,40 d. None of these e. 0.80

Solution

The Progenies obtained after crossing with the wild-type dominant mutant allele are as below

q+ r q r : 1 wild-type dominant mutant allele.

q r q r+ : 1 wild-type dominant Mutant allele

The proportion of the offsprin that we would except to have the wild-type phenotype( wild type is denoted by the
+ alleles and is dominant to the mutant alleles ) is:

=( (1+1)/2 )/100

= (2/2)/100

=1/100

=0.10

Conclusion :

Hence 0.10 is the proportion of the offspring will have the wild-type phenotype (wild-type is denoted by the + allele and is dominant to the mutant alleles).

Progeny obtained after crossing	Number of wild-type dominant mutant allele present
q+ r q r	1
q r q r+	1
Total	2