the colour blindness question (1 Viewer)

[~*pixie_poo*~]

was jack colourblind..... or not???

and how can you tell, when you dont know whether Nick, his father was.. or whether Maria, his mother was a carrier or normal??

what did you all write?

 

[danieljarvis]

his mum has a 1/2 chance of carrying. and so then he had a 1/2 chance of getting off her.. so overall a 1/4 chance. went through with teach n he got the same.

 

[melimoo]

i did a punnet square for maria being unaffected and then her being a carrier. and i assumed nick was unaffected

it worked out from the 2 punnets that it was 3/4 chance that he wasn't and 1/4 that he was. thats what i had anyway :/

 

[melimoo]

his mum has a 1/2 chance of carrying. and so then he had a 1/2 chance of getting off her.. so overall a 1/4 chance. went through with teach n he got the same.

i think thats the same as what i said....but i can't be sure. my brain doesn't work anymore. i was up since 5am doing bio

 

[MasterOfDisgyis]

Wasn't the colour blindness a sex-specific disorder meaning only a MALE could be affected? The female is the carrier, so even though Maria didn't have it her son still could have.

And it was a joke asking us whether her son WOULD or WOULD NOT get it because it was very uncertain. He MIGHT or MIGHT NOT. Thats what I said.

 

[~*pixie_poo*~]

Wasn't the colour blindness a sex-specific disorder meaning only a MALE could be affected? The female is the carrier, so even though Maria didn't have it her son still could have.

And it was a joke asking us whether her son WOULD or WOULD NOT get it because it was very uncertain. He MIGHT or MIGHT NOT. Thats what I said.

i said that too. thank god someone else thinks so too. lets hope we are right!!

 

[Mystienu]

yeah same.
the question didn't ask for a probability did it?

I just explained the two possibilies by describing both scenarios eg If the Mother was a carrier... this would happen... if not .... blah blah

What do you guys think of the influenza question?

 

[kyu_chan]

Hi all,

I used the Punnett Square working out as well but since Jack is a male, i found that he had a 50% chance of inheriting the disease...what do you think?

I did that also and I'm pretty sure it's right.

 

[kyu_chan]

What do you guys think of the influenza question?

Too tedious... I made bullshit for that one. We were checking the papers and I cam across the question... It scared me so much hehe ^^''

 

[pikto]

i did the punnet square with the sex chromsomes, and because jack is a male that would exclude 2 choices on there, therefore if his mum is a carrier i said he would have 50% chance of being colourblind...

 

[MasterOfDisgyis]

I did that also and I'm pretty sure it's right.

You still cant make an absolute rock solid answer with those. And thats what the question was asking (the way I read it). We're not talking about a mother and father both with brown hair and them asking us what colour the childs hair will be.

 

[funnybunny]

theres a 50% chance that he is colour blind if the mother is a carrier and 0% if the mother isnt a carrier. Nick's genotype doesnt matter because since Jack is a boy, he would get the Y chromosome from the father and the blindess is only on the x-chromosome (but u'd had 2 knoe that out of the q??)

 

[danieljarvis]

you couldnt get a definitive answer and they werent asking for a probability. so i wrote down the options of what COULD happen. i.e. if his mother gets the gene he has a 1/2 chance of being colour blind, and if she doesnt then he has 0% of being colourbilnd.. but i also wrote 1/4 overall to be safe 1/2 x 1/2 = 1/4 . simple! spoke to my teacher and he said i was right. i didnt draw a punnet square, i drew a pedigree ( family tree ) with there genotypes

 

[kyu_chan]

You still cant make an absolute rock solid answer with those. And thats what the question was asking (the way I read it). We're not talking about a mother and father both with brown hair and them asking us what colour the childs hair will be.

But the father (from what I've read) isn't affected, that means he has one normal X chromosome and one normal Y chromosome... And the mother being a carrier but not infected meaning the mother has one affected X chromosome but the other is fine. Then you cross them together and their son has a 50-50 chance... no?

 

[midnight_magick]

i also did a punnet square- it doesnt matter if Nick was colour blind or not because if you work it out, it doesn't affect Jack or whatevers chances. Maria could either be carrier or normal (from punnet square of her carrier mum and normal dad). there were 2 cases
*Dad and Normal Mum= in whch case no males could have C.b
*Das and C.b carrier mum= in which case half of the males will have C.b
So predicted that since we don't know mum's genotype, it can any of the above 2 cases. There is a greater chance of Jack not having C.b so i predicted he wouldn't be C.b.
Was that right? I think other ppl have posted something similar but was too exhausted to read them (sorry!) hehe.

 

[Abtari]

i wrote two answers:

0% chance of Jack being blind - condition: maria is normal (XBXB)
50% chance of Jack being blind - condition: maria is carrier (XBXb)

this is assuming that Nick was normal, i.e. not colour-blind...

 

[Abtari]

yeah midnight magick, youre right...

nick's genotype doesnt matter...cos he only transmits the Y onto Jack....


thus colour blindness is determined solely by Maria's condition....

since she can either be normal or carrier....Jack can either be definitely normal or there is a 50% chance of either normal or blind...

maria normal ==> jack definitely normal
maria carrier ==> 50% chance of jack being normal; 50% chance of jack being blind

 

[console]

it wasnt given that his jack's mum was or wasnt colour blind....apart from that his dad wasnt colour blind....so i put MAYBE he'll be colour blind, if she is carry it of not

 

[kyu_chan]

since she can either be normal or carrier....Jack can either be definitely normal or there is a 50% chance of either normal or blind...

maria normal ==> jack definitely normal
maria carrier ==> 50% chance of jack being normal; 50% chance of jack being blind

didn't the question state that the mother was a carrier? *cannot rmember the question anymore*

 

[midnight_magick]

yeah midnight magick, youre right...

nick's genotype doesnt matter...cos he only transmits the Y onto Jack....


thus colour blindness is determined solely by Maria's condition....

since she can either be normal or carrier....Jack can either be definitely normal or there is a 50% chance of either normal or blind...

maria normal ==> jack definitely normal
maria carrier ==> 50% chance of jack being normal; 50% chance of jack being blind

Hail Abtari!
i feel better about that question now