To the Media and Board of Studies officials (2 Viewers)

[shobadaynature]

i did a lil punnett square to make my point, but only did one for the case if Maria had been a carrier, then somewhat mentioned there's between a 0-50% chance of Jack being colour blind.
Then I put Jack is probably not colour blind...

It did ask for a judgement...hopefully a mark or 2 for that...

 

[elisabeth]

I did all the working out but didn't really make a judgement.. All I wrote was "if mother is carrier, 50% chance" and "if mother is homozygous normal, no chance of being colourblind"

 

[caxap]

The likelihood of her getting the disease is not reliant on her siblings. The chances occur, by the sperm "meeting" the egg which has the particular gene. There is a 50% chance that the egg will have the gene. That cannot be changed by previous children.

But could you use her siblings as evidence that unaffected male x carrier female can potentially produce affected children?

 

[missjelly_baby]

it is a sex-linked trait: therfore the father contriubutes the Y chromosome which has no affect on wether Jack would be colour-blind or not. Because Maria is a possible carrier (her father didn't show trait and she gets X chromosome for normal sight from him, her mother is a carrier so it is possible she is also a carrier), she can either give Jack X(N) for normal sight or X(n) for colour-blindness. Therefore there is a 50% that Jack will be colour-blind and whether he is colour blind depends on the allele he inherits from his mother.

 

[liquid.ghoul]

But could you use her siblings as evidence that unaffected male x carrier female can potentially produce affected children?

You probably could, but I'd guess it is better to show your knowledge of how sex linked traits are passed on. Therefore, it is better to show it the punnet square way.

 

[Prashanthy]

lol. this is more like a "wat'd you say for the coulour-blindness question" thread, than anything to do with the media/BOS officials