AQA A2 BIOL5 22nd June 2012

well the essay did talk bout shapes fitting in cells and organisms...so i wrote abit about courtship behaviour and how the sexual organs have to be the correct orientation for fertile offspring to be produced and so populations dont get extinct lol

Reply 3501

F1's Finest

21

Original post by Starlight94

I didn't have a clue what IAA was :/

it's mentioned in the nelson thornes book.

Reply 3502

jodiedoodles

Original post by SmithytheDrummer

Has an unofficial mark scheme been made yet?

http://www.thestudentroom.co.uk/showthread.php?t=2039285

Reply 3503

jodiedoodles

Original post by najd5

anyone got a copy of the paper?

http://www.thestudentroom.co.uk/showthread.php?t=2039285

Reply 3504

Fizzeh

4

Okay this is going to sound hilarious.

When I did the IAA question, I very wrongly thought in a brainfart moment that IAA inhibited cell elongation regardless of where it was. So I wrote that it inhibits cell growth in the bottom of the root because the IAA diffuses to the bottom of the root tip. So the top of the root grows more and it bends downward toward gravity.

So my complete mistake in knowledge might have gotten me marks. xD

Also I got the last one wrong with the cut in half tip, but if the above is correct I would assume thinking back that because the second one grows horizontally despite having no root tip, the half-cut one would still bend down because the bottom half has less IAA but still enough to inhibit a little, so the top half keeps growing horizontally but it still bends because the bottom of the tip grows less.

... o_o I think the thing that got me to believing all IAA inhibited was because the second diagram showed the root growing horizontally despite having no tip, whereas in the IAA shoot examples in the book, the shoot didn't grow any more without a tip; only if it was replaced.

Reply 3505

Yosemite80

Original post by Fizzeh

Okay this is going to sound hilarious.

When I did the IAA question, I very wrongly thought in a brainfart moment that IAA inhibited cell elongation regardless of where it was. So I wrote that it inhibits cell growth in the bottom of the root because the IAA diffuses to the bottom of the root tip. So the top of the root grows more and it bends downward toward gravity.

So my complete mistake in knowledge might have gotten me marks. xD

Also I got the last one wrong with the cut in half tip, but if the above is correct I would assume thinking back that because the second one grows horizontally despite having no root tip, the half-cut one would still bend down because the bottom half has less IAA but still enough to inhibit a little, so the top half keeps growing horizontally but it still bends because the bottom of the tip grows less.

... o_o I think the thing that got me to believing all IAA inhibited was because the second diagram showed the root growing horizontally despite having no tip, whereas in the IAA shoot examples in the book, the shoot didn't grow any more without a tip; only if it was replaced.

well it *does* inhibit elongation in the roots though! :biggrin:

shoots didnt come into it anywhere :3
if tip cut in half then half the normal amount of IAA would affect root cells, so elongation is inhibited half as much as the first expt, which is why the deflection angle was half of the angle in the first expt, which is what you wrote :3
no tip just means no IAA to affect curvature but it would still grow probably... :3

Reply 3506

kingam

Was talking about starch be relevant in the shape essay :frown:

Reply 3507

neekha

Original post by Sockhead

Haha, hells yes! Maybe a bonus one for comedy factor? Heres hoping..

Dude you totally should have! I wouldn't be alone that way :P

You're such a legend! Wish I thought of that :tongue:

This was posted from The Student Room's iPhone/iPad App

Reply 3508

Fizzeh

4

Original post by kingam

Was talking about starch be relevant in the shape essay :frown:

As long as you somehow managed to relate it to shapes fitting together then it should be found relevant. :smile:

Reply 3509

chill543

Original post by kingam

Was talking about starch be relevant in the shape essay :frown:

yeah i did!

Reply 3510

kingam

Original post by chill543

yeah i did!

Haha good not only one then :smile:

Reply 3511

I failed badly

I may have made a big mistake in the bacteria essay, I talked about
-parts of nitrogen cycle (not every part as didn't have time so talked about nitrifying bacteria saprophytic bacteria)
-in vivo cloning
- h and v gene transmission (I did mention something about Mrsa)
-cholera
-tb

When I talked about resistance I included it in the h and v gene transmission part and explained how other bacteria may develop resistance through horizontal gene transmission etc. Would this be ok?

Reply 3512

najd5

Original post by I failed badly

I may have made a big mistake in the bacteria essay, I talked about
-parts of nitrogen cycle (not every part as didn't have time so talked about nitrifying bacteria saprophytic bacteria)
-in vivo cloning
- h and v gene transmission (I did mention something about Mrsa)
-cholera
-tb

When I talked about resistance I included it in the h and v gene transmission part and explained how other bacteria may develop resistance through horizontal gene transmission etc. Would this be ok?

All that you've said is fine, but you have to make sure your focus was on how they affect the 'lives of humans and organisms' not just what bacteria do.

Reply 3513

ReMos

9

My bacteria essay looked something like this:

Intro

How bacteria cause disease
TB
Cholera

Nutrient recycling and the nitrogen cycle

Mutualistic bacteria, lichens (quite short :s-smilie:

)

Plasmid allows them to be industrially used to become GMOs
Insulin production
Enzyme production for the food industry

conclusion

all took a little less than 4 sides....
it seems a bit short
will i be fine? :s-smilie:

Reply 3514

I failed badly

Original post by najd5

All that you've said is fine, but you have to make sure your focus was on how they affect the 'lives of humans and organisms' not just what bacteria do.

That may be where I lose some marks I think for relevance. I did however at the end of each paragraph say how what the bacteria do affects the lives of humans and other organisms. So hopefully will be ok. :smile:

Reply 3515

handsome7654

Guys in the shapes essay I only talked about enzymes and hormones. But in great detail about certain hormones and enzymes. Will I not get any breadth marks?

Reply 3516

Scott.M

12

It was exactly what I feared but also, based on past papers and from my experience of A2 AQA Biology, expected it to be: tons of how science works type questions (by how science works I mean the general knowledge questions).

I'm sorry but I find it shocking how they find the room to ask us a lot of how science works based questions, but nothing about the nervous system bar synapses, which was a MASSIVE topic I felt.

I think all how science works questions should be replaced with application of knowledge questions so that it's at least got something to do with what you have studied. I feel HSW questions favor those who study the least, because the answer to them is general knowledge rather than exam specific knowledge. I feel I do my part by putting the effort into studying and I want them to do their part by examining me on it and giving me a grade reflective of how much I have studied compared to the competition I'm up against, only to be disappointed to find a ton of HSW marks.

I have no idea how I've done because of:
A) the sheer volume of how science works questions, where we may think we have the correct answer based on an unofficial markscheme but AQA might decide on something else as the correct answer
B) the 25 mark essay - no unofficial markscheme can tell me how well I done on it, and I don't have a clue either
C) the grade boundaries can fluctuate a lot in biology compared to my other exams
D) kind of related to C), but AFAIK this was only the third paper of its kind, so it's likely the grade boundaries will rise purely due to students getting more used to this exam

It was also rather lame to think I'd done alright on the shapes essay by talking about enzymes, hormones and muscle contraction, only to come on here and see that other people have practically wrote a book on it. Idk how they managed to fit it all in in the 40 minutes. XD

Reading through the unofficial markscheme and being very harsh, and then just assuming I've got 10 on the essay cos that's usually as low as I get since the categories other than scientific content are kinda a free 2-3 marks each :P, I think I've got ~60/100. Hoping that will be enough for the high D I need to get my grade.

(edited 11 years ago)

Reply 3517

Yosemite80

i wrote quite a lot of topics for the bacteria essay but just realises that i managed to get tb mixed up with fibrosis (did this in unit one last year too :s-smilie:

), i think the rest of the essay was fine though, would i lose a lot of marks just for the tb mistake?