Question

A PROBLEM ON GENETICS

Answer 1

Human skin colour is controlled by several gene pairs. Let us assume here, that there are just three gene pairs on different chromosomes and that for each pair there are two alleles - an incompletely dominant one that codes for melanin deposition and an incompletely recessive one that codes for no melanin deposition. If a very dark skinned person marries a very light skinned woman, what will be the chance that their offspring will have very dark skin?

Answer 2

A) 0
B) 1/4
C) 5/8
D) 9/64

Answer 3

What do you think?

Answer 4

As a matter of fact I've been trying this for some time now, my cousin gave this to me...I want your solving method 4 this :)

Answer 5

We call this type of questions as Bluff questions xD

Answer 6

They appear to quite big and complicated but are simple.

Light skin = aabbcc
Dark skin = AABBCC

A cross between two will lead to pure \(\sf F_1\) hybrids AaBbCc

None of the progenies will have Pure dark or Pure light skin

Answer 7

Ok Doc thanks!

Answer 8

No problem c:

Answer 9

But if the \(\sf F_1\) progenies mate among each other then 1/64 of the \(\sf F_2\) progenies will be light skinned and 1/64 will be dark skinned