AQA BIOL2 Biology Unit 2 Exam - 26th May 2011

can you remember what you got for the DNA hybrid questions dont mind me asking

Are you talking about the one where it said how temperature is used to calculate percentage?

If so, my answer was:

Upon heating, the degree to which the hybrid strands are still linked/as one is measured (this in temp) and is recorded progressively - % can hence be calculated from this and the temps recorded;

...or large surface area to volume ratio.

I can't remember the question in full, did it ask what higher temps suggest? I am sure it says how is temperature used to calculate %.. anyway, the table question, you didn't get tricked did you? The highest % wasn't the two species most closely related because they already were the same species

well thats what i wrote it should be kk i think

Can I just ask about this frog question, what does a large surface area to volume ratio have to do with anything?

Also i don't know why they give us so many lines to write an answer like that, you could fit it in one line...

Can I just ask about this frog question, what does a large surface area to volume ratio have to do with anything?

Which question?

Oh, I was talking about another question.. I can't remember this 3 marker but if that is what you put then yes you have all 3 mark points:

Higher temps means species are more closely related;
More complementary base pairing within hybrid strands;
Hence more hydrogen bons;
As a result, more heat is required to seperate strands, the higher the temp, the more closely related

No there was another 2 marker after the table that said something else, but never mind, and no neither do I

It was, A will be around 60/61

It was, A will be around 60/61

It was, A will be around 60/61

Sorry i don't understand the answer... Could you please explain it a little more? Like what did you write? I definately got it wrong i think

I swear it was similar in difficulty to Jan 11 and that has A at 54...

Sorry, what question was this?

I've forgotten the context of my reply and can't be bothered to trawl through the thread to search it out.

If it was something about frogs' eggs and pesticides, which I think it was, then a large surface area to volume ratio means that the pesticide diffuses more rapidly into the organism and so, this effect is more pronounced as frogs' eggs are small.

Not entirely sure what the question was, but the answer was probably something along those lines.

jan 11 was easier i think lol less how science work questions

I just said they were small and not mature - hence more volatile to pesticide or something like that.. and for the evaporation I said the frogs were perhaps more exposed - ahh dear

I am in AS yes, and that is actually correct but surely that's over the top from AQA, it was 2 marks