C Chegg Stud x v C 5A GAT AT Gi x Mc Chegg Study x C Chegg s

(C Chegg Stud x v C 5A, GAT AT Gi x Mc Chegg Study x C Chegg study unchPad Quiz on Probl x Chegg Study x M Ma Iledgeo x b5ta1d900e72 491b9et2af8b95b16d9c SeBa78a177a14a2fa545ta4t3c a O www.macmillanhighered.com Done Quiz on Problem set 9 9. Additional question 5d A, B, and C are independently assorting Mendelian genes controlling the production of a purple pigment. The alternate alleles that give abnormal tunctioning of these genes are a, b, and c. A purple individual of genotype AA BBCC was crossed with a yellow individual of genotype aa bb cc to produce a purple F1. F xF1 crosses were perfonned and the F2 progeny where either yellow, orange, red or purple. Assume that A B. and C act in a pathway as follows yellow -oo orange rad purple What proportion of the F2 progeny will be puuple? 9/64 9/16 1/4 27/64 3/16 9 of 9 Save Submit Remalning: 1:48:00 Start: 10:40 PM 2/26/2017

Solution

(c) 27/64

AABBCC (purple) X aabbcc (yellow)

F1 AaBbCc (yellow) X AaBbCc (yellow)

Usual dihybrid ration is 9:3:3:1.

To get a trihybrid ratio, multiply this ratio with 3:1, the monohybrid ratio. We get 8 classes of progeny

27:9:9:9:3:3:3:1.

The first class is that of the purple one with the genotype A_B_C_. This class includes 27 out of 64 individuals. So, the ratio of purple individuals is 27/64. Alternatively, one can also draw the Punnett square.