A heterozygous, but phenotypically wild-type parrot (gray body color and normal wings) was mated to a white parrot with deformed wings. The offspring had the following phenotypic distribution: 720 wild type; 780 white-deformed wings; 280 white-normal wings; 220 gray-deformed wings. What conclusion is likely from these results?

Respuesta :

Answer:

Body colour and wing shape are linked genes

Explanation:

Suppose,

body color gene = A

wing shape gene = B

A test cross is being done between heterozygous but phenotypically wild type parrot ( AaBb ) and white parrot with deformed wings (aabb):

If the genes showed independent assortment, the ratio of progeny in this test cross would have been 1 : 1 : 1 : 1 i.e. all the different types of progeny would have been almost equal to each other in number

But according to the given data, the progeny is :

wild type : 720

white - deformed wings : 780

white - normal wings : 280

gray - deformed wings : 220

Hence, the number of offspring is not same in each category. Few combinations have higher number of parrots and others have lower number of parrots than expected value. This is a classic example of two linked genes where the parental type is produced in more numbers than the recombinant type.