the colour blindness question (1 Viewer)

[MiniT]

Well everyone's already answered this but meh I'll post what I did too.

First I established the mothers genotype as being a carrier and normal, because she could have been both. Then I established the father's genotype as being normal since there was no history of colour blindness in his family.
Then I drew 2 punette squares outlining the possible outcomes. Final answer 3/4 chance that he's normal and 1/4 chance that he's colour blind.

 

[missjelly_baby]

it said that maria was a carrier and nick wasn't. As it is a esx-linked trait the father had X(N)Y genotype, mother had X(N)X(n) where X(N) is normal sight, X(n) is colour-blindness. Now as kid was male must inherit Y from father. Therefore 50% chance is colour blind as can either inherit X(N) or X(n) from mother:

Possible genotypes X(N)Y - normal
X(n)Y - colour-blind

btw i don't know if someones already said this as didn't really read many other posts

 

[_blank]

it said that maria was a carrier and nick wasn't.

It never stated that Maria was a carrier - only that her family had a history of colorblindness.

 

[mnanda88]

its sex linked nd recesive ... so if da mum had it she wuld prob show it .... no?
and if the dad had it then he wuld show it ... more likely 4 lil biy not 2 hav color blindness ... whoeva is color blind neway