After the EXAM (feedback)

[susien7]

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

i said they had different reproductive structures and 'mating calls' but i was meant to say something smarter i just couldnt think of the word

[205ism]

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? :|

the child would only have one value for the DS gene than if it was on the x chromosome given that it was male

[Ekky]

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?

i saw a Y chromosome..so i put A

[Faraz]

Lol I dont think hominids used mating calls since they had other forms of communication.


I did that it was a male

the other didnt seem correct to me.

[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? :|

the child would only have one value for the DS gene than if it was on the x chromosome given that it was male

aha shit that's right. hmm so confusing.

[susien7]

Lol I dont think hominids used mating calls since they had other forms of communication.

lol yeah i really couldnt think of the word. hopefully my difference in reproductive structures will be suffice

[bucket]

Question 6a)
"Scientists select a particular restriction enzyme from an available range, explain the reason for their choice."
I had no idea about this one , kind of had a wild guess.

[username]

Question 6a)
"Scientists select a particular restriction enzyme from an available range, explain the reason for their choice."
I had no idea about this one , kind of had a wild guess.

Because they needed one that recognized sequences that were common in both individual 1 and 2?

[lacoste]

particular restriction enzyme cuts at specific recognition sites, .... how many marks 2 or one?

[lacoste]

what was the ans to the " what appropriate method would be able to date the frogs?"

[NE2000]

It was really good that the examiners stuck to the stuff that we would have revised: like transcription, translation, replication, also good to see some questions where you have to work out the ratios in the offspring.

Unfortunately that's not the case...

I really bombed out on the bomb question
I put something like, they would have to have to check background radiation that they were exposed to and they would have to check the capability of the nuclear radiation to induce the spontaneous....argh...I stuffed that up hard-core.

Then even the easy questions I stuffed up due to over-concentrating on the ones I was basically guessing at. The RFLP question I knew all along but my answer was really really badly worded. Same with the frog question (what did people say caused their isolation? I said the habitat changes etc. etc.) and for the Neanderthal vs. Homo sapiens I talked about possible gamete mortality; I think they'll accept anything feasable for that (not mating calls though, coz I don't think humans have mating calls). Then the last question, I need to look at that again. I talked a bit about finding fossils of H. sapiens nearby but it wasn't until after the exam that I felt that I could have actually made that answer work. A lot of people I know talked about mtDNA but I thought they meant fossil evidence. Also for the bomb question, a lot of people talked about issues like privacy etc. Is that right or is it more experimental procedure?

[NE2000]

what was the ans to the " what appropriate method would be able to date the frogs?"

I said molecular clock using an amino acid like beta haemoglobin with a steady rate of mutation

[bucket]

1 mark only.
I wrote something similar to what username said.

what was the ans to the " what appropriate method would be able to date the frogs?"

I wrote use of mtDNA as a molecular clock? LOL totally guessed that one too >.< I did so bad!

[susien7]

are the frogs still living? i said something about using mitochondrial dna.. but i don't think that's right at all

[JL_91]

Does anyone have any idea how many marks you were able to drop across the two exams to get a 50 last year? Or a 45? Just curious about my chances. My teacher really wants me to hit the high 40s >_< but I'm starting to worry because I've realised 2 marks' worth of mistakes already. And probably a LOT of bad wording too.

What appropriate method for the frogs - I put comparing the number of base differences between the frogs' DNA (more differences=they have been diverged for a longer period of time). Something like that, I can't remember my exact wording. DNA hybridisation in other words.