Mendel crossing with colour blindness (Probability)

Genetics as it applies to evolution, molecular biology, and medical aspects.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
Posts: 2
Joined: Wed May 22, 2013 9:37 pm

Mendel crossing with colour blindness (Probability)

Post by tomkoolen » Thu Jun 13, 2013 10:56 pm

Hello everyone,

I cannot seem to grasp the idea of how I have to use probability in this problem:

"In Oslo 18121 school children were tested for colour blindess. These are the results:
Male: 8324 not colour-blind, 725 colour-blind.
Female: ? not colour-blind, ? colour-blind.

Determine the number of colour-blind females if colour-blindness is caused by a monogene recessive X-chromosomal gene."

My work so far:
Males from the parent generation can have the X^AY (not colour-blind) or X^aY (colour-blind) genotype. Females have X^AX^A, X^AX^a or X^aX^a (colour-blind) genotypes. However, I don't know how I need to combine these possiblities with the results for the male decendants. Does anyone have an idea?

Thanks in advance,
Tom Koolen

Post Reply

Who is online

Users browsing this forum: No registered users and 4 guests