Someone please post 2010 sample solutions?

[Poreotics]

yeah I know.. its your own work ==

thanks thushan, really appreciate it

[thushan]

Just a quick note on the centromere question:

Had a chat to a VCE assessor, and they were apparently looking for 1. a mention of hybrid ancestors possessing one fused chromosome and two unfused chromosomes in a somatic cell being sterile, causing instant speciation and 2. this stops gene flow between two populations and allows the human line to diverge from the chimpanzee line

[onerealsmartass]

Thushan do you think that a mark will be awarded if you state somewhere in your response that the human line diverged from the chimpanzee line as a result of this fusion?
i sure hope so

[pi]

Just a quick note on the centromere question:

Had a chat to a VCE assessor, and they were apparently looking for 1. a mention of hybrid ancestors possessing one fused chromosome and two unfused chromosomes in a somatic cell being sterile, causing instant speciation and 2. this stops gene flow between two populations and allows the human line to diverge from the chimpanzee line

one thing I don't understand about this question, wouldn't there need to be two 'hybrid' ancestors of different genders to produce fertile offspring. In the question, never is there a mention of it happening to more than one individual, and as it seems pretty rare that two chromosomes would fuse together in a population of chimps/whatever-they-were, this question is hard to make any explanations regarding evolution due to the near impossible chance of this happening... Just my post-mortem analysis of that question.

[thushan]

@onerealsmartass - you'd get 1/2

@Rohit - yeah, the specifics are complicated, but i remembered reading about instant speciation through fusion of chromosomes in nature...there are quite a few dodgy explanations for this

[pi]

@onerealsmartass - you'd get 1/2

@Rohit - yeah, the specifics are complicated, but i remembered reading about instant speciation through fusion of chromosomes in nature...there are quite a few dodgy explanations for this

The question sucked, it is so unlikely that evolution would ever occur, there would be instant speciation (agree there), but for evolution, two hybrids are needed of two different genders in the same generation living close to each other ideally in the same population in order to mate (that was a mouthful).

[onerealsmartass]

yay so hopefully ill get at least 1 mark for that cant quite remember what i wrote abuot them fusing though...

Rohtpi would your friends mum give you any hints as to what she thinks the A+ cut off will be??

[thushan]

Chromosome fusion - then centromere fusion
Could hypothesise that since a set number of spindle fibres branch out during meiosis, that whist the chromosome had two centromeres the ancestor was fertile and then it'd be relatively likely that in some of the new individuals (across many generations) that centromeres fuse <could be a common event in chromosomes with two centromeres?> and then that band of individuals form the basis of the human line? Just a hypothesis

[onerealsmartass]

lol ive already erased a lot of the biolgy stuff out of my brain xD
how can you guys still remember this?

[pi]

yay so hopefully ill get at least 1 mark for that cant quite remember what i wrote abuot them fusing though...

Rohtpi would your friends mum give you any hints as to what she thinks the A+ cut off will be??

I have asked, and she said she hasn't been told yet, but she said it should be over 60 (which we all knew anyway!)

Chromosome fusion - then centromere fusion
Could hypothesise that since a set number of spindle fibres branch out during meiosis, that whist the chromosome had two centromeres the ancestor was fertile and then it'd be relatively likely that in some of the new individuals (across many generations) that centromeres fuse <could be a common event in chromosomes with two centromeres?> and then that band of individuals form the basis of the human line? Just a hypothesis

Interesting hypothesis! I still think the question sucked though, far too random and lacked a bit information

[thushan]

dw so do i

[Jdog]

did he think it was easy exam?


did he give a predicition of cutoff?

[stonecold]

Just a quick note on the centromere question:

Had a chat to a VCE assessor, and they were apparently looking for 1. a mention of hybrid ancestors possessing one fused chromosome and two unfused chromosomes in a somatic cell being sterile, causing instant speciation and 2. this stops gene flow between two populations and allows the human line to diverge from the chimpanzee line

IIRC, wasn't the question specifically asking about centromere inactivation?

If so, then that answer is utter rubbish because it does not even address the question.

[Jdog]

i thought the quesiton was about centromere inactivation and the effect it would cause,

i reckon you still had to mention meiotic behaviour when one centromere was lost.

[stonecold]

i thought the quesiton was about centromere inactivation and the effect it would cause,

i reckon you still had to mention mitotic behaviour when one centromere was lost.

+1

this is the answer to the QUESTION ASKED.