Fruit color in a particular plant is controlled by a set of three QTLs (quantita
ID: 202426 • Letter: F
Question
Fruit color in a particular plant is controlled by a set of three QTLs (quantitative trait loci, or “polygenes”) that work in an equal and additive manner. Each QTL has two alleles (i.e., A and a); each allele represented by a capital letter produces “one dose” of yellow pigment, while alleles represent with lower case letters do not produce any pigment at all. If a trihybrid plant (A/a; B/b; C/c) is testcrossed, what proportion of the offspring will have a fruit colour phenotype that is different from both the trihybrid and the tester parents? Assume no environmental effects. Assume all three QTL independently assort.
Explanation / Answer
A/a,B/b,C/c X aabbcc
ABC abc . ABc AbC aBC abC. aBc
abc AaBbCc aabbcc AaBbcc AabbCc aaBbCc aabbCc aaBbcc
Abc
abc Aabbcc
Only the first two offspring resemble the parents i.e. tihybrid and tester plant but the rest are different from them producing different shades of yellow
Thus the proportion is 6/8 or 3/4
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.