the colour blindness question (1 Viewer)

[console]

yep ur 100% rite

 

[*ccs*]

punnett square

it was 25% chance coz he could have inherited either the normal X from the mother or the affected X from the mother

X' Y


X' X'X' X'Y


X X'X XY

see there is 25% chance of him inheriting it with the X'Y

it doesnt matter if nick had it or not because only the Y gets passed on from the male parent and the defect is carried on the X chromosome..which is what the question was asking.....SEX LINKAGE

 

[rusty_rouge]

it was 25% chance coz he could have inherited either the normal X from the mother or the affected X from the mother

X' Y


X' X'X' X'Y


X X'X XY

see there is 25% chance of him inheriting it with the X'Y

it doesnt matter if nick had it or not because only the Y gets passed on from the male parent and the defect is carried on the X chromosome..which is what the question was asking.....SEX LINKAGE

Mmmm I put that down too - that Jack had 25% chance, doing 50% times 50% to give 25% - was that right? Lol, now everyone's got me second guessing myself...

 

[Abtari]

it was 25% chance coz he could have inherited either the normal X from the mother or the affected X from the mother

X' Y


X' X'X' X'Y


X X'X XY

see there is 25% chance of him inheriting it with the X'Y

it doesnt matter if nick had it or not because only the Y gets passed on from the male parent and the defect is carried on the X chromosome..which is what the question was asking.....SEX LINKAGE

If the mother was affected rather than just a carrier he would of had a 50% chance because she would have passed on either one of her affected X' to him

what do u mean "if the mother was affected rather than just a carrier?"

explain how that condition even arises???

the mother (maria) cannot be affected, she's either normal or carrier...look at ur punnett sqaures again

 

[Abtari]

the question didnt mention anything about the mother (maria)'s state...

u had to deduce her genotype from the clues they gave u, i.e. her pop was normal and her mum was carrier....hence she can only either be carrier or normal

 

[SaMi5]

hey all... i only read a few comments and most said they used punnet squares and i thort it said to do a pedigree... or could ya do punnet squares???

 

[*ccs*]

lol yeh i knw something looked wrong soz... i think ive just realised i put the wrong numbers in...coz i did my punnett and got 25% but i didnt actually write that only showed it there..i hope they look at it


Sami5.....u had to draw the pedigree in the box (to show u could construct one) but u could use a punnett to work out if jack was a carrier or not

 

[ishq]

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

The question said that the mother's mother was a carrier. So, there were two options for the mother.

To be a carrier or not to be - That is the question..


Can't get fucking Hamlet out of my head.

 

[adrenaline88]

There were too many scenarios for 2 marks so I reckon it was a damn mistake:
Nick unaffected x Maria carrier
Nick unaffected x Maria unaffected
Nick affected x Maria carrier
Nick affected x Marier unaffected
There was no information about whether or not Nick was colour blind or not and the Board of Studies shouldn't expect us to make ridiculous assumptions based on no information in the question!

 

[ishq]

There were too many scenarios for 2 marks so I reckon it was a damn mistake:
Nick unaffected x Maria carrier
Nick unaffected x Maria unaffected
Nick affected x Maria carrier
Nick affected x Marier unaffected
There was no information about whether or not Nick was colour blind or not and the Board of Studies shouldn't expect us to make ridiculous assumptions based on no information in the question!

Nick's genotype did not matter! Jack was a BOY. Only 2 possibilities for 2 marks

 

[kyu_chan]

The question said that the mother's mother was a carrier. So, there were two options for the mother.

To be a carrier or not to be - That is the question..


Can't get fucking Hamlet out of my head.

LOL! And I have King Lear >_< Egh!! (pomo next!)


Oh, the mother's mother but not the mother... I see ^^''

 

[frey05]

well i just put no coz i thought it might skip a generation....you know how it does sometimes when it's sex-linked.......i hated that question :'(

 

[kyu_chan]

It may, but it may not also. so depends really.

 

[bluebaby]

hmmm since its x-linked, the colour blind will not be expressed on female...therefore the child will not get colour blind...also it says predict...not probability...=P good luck!

 

[danieljarvis]

hmmm since its x-linked, the colour blind will not be expressed on female...therefore the child will not get colour blind...also it says predict...not probability...=P good luck!

just because its not expressed on the female, doesnt mean she cant pass it on to her offspring

 

[bluebaby]

hmm i dun even think the daughter carrys it -_-

 

[Shell]

lol omg. i did all the punnet squares and everything. but then i thought the question was really asking yes or no? none of this well 50% he may be. i just took a stab and said yes he is colour blind.

 

[danieljarvis]

taking a stab.. now thats australian. im on my 5th beer since 1 o clock! lets all get naked

 

[espiroski]

It really doesnt matter if the father was infected or not, because regardless he passes down the Y chromosome...therefore they didnt have to specify in order to assume whether the child is affect. All the power was held in the hands of Maria.

 

[lala2]

I just wrote down that Jack could or could not be colour blind, depending on his mother's genotype. I forgot to put down percentages, but I wrote two Punnet squares so that should at least get me a mark or two.