After the EXAM (feedback)

[username]

What about the restriction enzymes one, haha. I sat there for 5 minutes just drawing stupid lines and where they'd cut. I gave up and put A.

[205ism]

Anyone know the correct answer to the DNA graph? You had to plot B and D or something.

pretty sure b was 4 and d was 2, it was unclear but i though it was refering to 'n' number of chromosomes

[bucket]

With the question regarding the mother claiming that the boy wasn't her son, what did you guys write?
I wrote that her claim is false because the size of the alleles in the son were exactly the same as that of the mother's, and the fact that the boys sister's allele sizes were a combination of both the mother's and father's alleles suggests that they are found on the X chromosome (the boy only received an X chromosome from his mother which is why they are identical), but I wasn't confident with this because it seemed like too much thinking for only 2 marks.

[Ekky]

What about the restriction enzymes one, haha. I sat there for 5 minutes just drawing stupid lines and where they'd cut. I gave up and put A.

I think the answer was C- 3,5,2

[puffy]

I said O as the blood group...

and yes C - 3,5,2

[JL_91]

Ekky - C: 3,5,2 is correct

With the question regarding the mother claiming that the boy wasn't her son, what did you guys write?
I wrote that her claim is false because the size of the alleles in the son were exactly the same as that of the mother's, and the fact that the boys sister's allele sizes were a combination of both the mother's and father's alleles suggests that they are found on the X chromosome (the boy only received an X chromosome from his mother which is why they are identical), but I wasn't confident with this because it seemed like too much thinking for only 2 marks.

The mother's claim was correct - she was given the wrong baby. You had to check if this baby had inherited alleles from both the mother AND her partner for both gene loci. For the FGA loci, it appeared that he had inherited from both. But if you check the DS (?) locus numbers, the baby did not receive an allele from both his supposed parents. So the baby was not theirs.

[205ism]

With the question regarding the mother claiming that the boy wasn't her son, what did you guys write?
I wrote that her claim is false because the size of the alleles in the son were exactly the same as that of the mother's, and the fact that the boys sister's allele sizes were a combination of both the mother's and father's alleles suggests that they are found on the X chromosome (the boy only received an X chromosome from his mother which is why they are identical), but I wasn't confident with this because it seemed like too much thinking for only 2 marks.

nah, it wasn't her child

at locus DS the child had the allele variations 11,15
the mother had 11,15
the father had 14,16

because the child gets one allele from each parent the child couldn't have been that mother's given that there were no mutations (and she wasn't sleeping around)

[Faraz]

Yeah i Guessed that one but I also did C 3,5,2

[Faraz]

No I think that just means those genes did not cross over and where the same from the start???

[toomoo]

[/quote]

The mother's claim was correct - she was given the wrong baby. You had to check if this baby had inherited alleles from both the mother AND her partner for both gene loci. For the FGA loci, it appeared that he had inherited from both. But if you check the DS (?) locus numbers, the baby did not receive an allele from both his supposed parents. So the baby was not theirs.
[/quote]

Got that also!

[bucket]

Yeah but as I said, if these alleles were on the X chromosome, the son would only get the X chromosome from his mum as his dad would contribute a Y chromosome, so you would expect them to have identical alleles.
And also as I said, the only reason his sisters have combinations of alleles from both parents is because they get an X chromosome from both parent!
For FGA the baby didn't inherit for both, the mother was 20,20 and so was the baby. And also, what are the chances that the 'wrong' baby would have identical alleles to the mother? :|

[username]

And Homosapiens and Homo afeuraljasda were unable to interbreed because different species?

[susien7]

Well, after reading this forum i'm fretting haha. I know i definetly got the bomb one wrong I got confused. But i do think that last years  was harder than this one. i agree with jl_9i in her reasoning for her claim being correct. bucket, your reasoning i do not understand. haha. um yes overall i think it was a good exam, not easy, but not  hard. anyone?

[Nelle91]

I know this is probably an easy question but for question 2 in multiple choice. It shows a karyotype.
It asks whether it
a. a male
b. defective allele
c. extra number 13 chromosome
... i can't remember d
do u guys remember what you put?

[Faraz]

yeah I just said they had to much genetic difference for interbreeding to occur or for fertile offspring's be produced