Question

Form a small discussion group and decide on the most likely genetic explanation for each of the following situations; a. A man who has red–green color blindness and a woman who has complete color vision have a son with red–green color blindness. What are the genotypes of these three people, and how do you explain the color blindness of the son? b. Cross A performed by Morgan and shown in Figure 3.18 is between a mutant male fruit fly with white eyes and a female fruit fly from a pure-breeding, red-eye stock. The figure shows that 1237 F1 progeny were produced, all of them with red eyes. In reality, this isn’t entirely true. Among the 1237 F1 progeny were 3 male flies with white eyes. Give two possible explanations for the appearance of these white-eyed males.

Answer 1

A)

Color blindness is A sex linked recessive inheritance . In this case, male has genotype of Xc Y, woman has genotype of XcX and son has genotype of Xc Y.

Please look in the image for solution:

kreras Man Carrier IWoman (CoLor blncl) Normal) amc FXX orbind nuC Nermal Daughter Souahter Som

B)

The cross occurs in following manner:

shite Red)

The white eye color progeny are formed because of following reason:

* During gamete formation in female, there is occur translocation of R gene from one X chromosome to the other X chromosome. When the gamete containing no R gene fuse with You chromosome give rise to white progeny.

* There is mutation occur occur in the R region which will leads to r gene formation. Now this leads to white eye color.