[ZeeBurb]

(Original post by whc23)
I have put together an unofficial answer scheme but the file is too big to upload. Please note that alternative answers may still get marks and I have not covered the essay questions. The pdf can be downloaded from my public drop box here:

https://www.dropbox.com/sh/2jki5n9tatct8se/VsHm-Er4e_

If you find this useful, I would appreciate it if you would visit my blog below and click on an advert or two.

Cheers

http://cambridgeacademic.blogspot.co.uk/

Some of your answers are worded in a way which may not get marks, e.g peak of oestrogen just before LH peak,
you would probably want to say rapid increase of LH conc shortly after increase in oestrogen conc.
And things like that.

Also your implanon answer would only get 0/1/2 marks I think, the mucus stuff is not on the spec... you would probably have to talk about how progesterone inhibits FSH and LH, so low FSH conc and the follicle does not develop, no oestrogen secreted from developing follicle so lining of endometrium can not build up and no FSH/LH surge associated with high conc oestrogen above the critical level so no ovulation, egg can not be fertilised.

4a) you need to talk about chemoreceptors in the walls of the aorta/carotid artery and also the medulla oblongata, so you'd get 1 mark

5bi) You should talk about how successfully transformed egg cells would glow green in fluorescent light, so it would act as a gene marker

5ci) not sure if they'd have that on the spec, I talked about damage to DNA in the nucleus during transplantation leading to embryo not developing fully. Your answer would suggest it would be impossible to get live births from this method.

6a) include gluconeogenesis

6biii) in this evaluate question you should include a point to support it, like it does keep blood glucose low for quite a long time
I don't think the diet suggestion is strong, I'd talk about how gene therapy would need to be repeated as the cells die, and the cost of such treatment/secondary immune response risks of it not working

8bi) not PCR product, say it moves least far in the gel and is therefore longest fragment, most repeats

8biii) wouldn't 1 band mean you are heterozygous not homozygous for the allele with the repeats

9e) I said that answer, but people have also said that choose a bull which suffers from heat stress less

9g) Talk about variation due to mutation so some individuals will have the lactose tolerance allele and some will not,
then increased reproductive success of individuals with the advantageous lactose tolerance allele in these countries


My answers are more AQA markscheme like

[laughingbagel]

For the injection vs. gene therapy question, would I get any marks for saying that: Viruses can multiply in cells, so treatment wouldn't need to be given as often (at least 8 months at a time, whereas insulin injections are needed daily); and also that the gene will only be transcripted when it's needed in cells that produce insulin, whereas people need to carefully monitor and work out when to give insulin.

[ZeeBurb]

(Original post by laughingbagel)
For the injection vs. gene therapy question, would I get any marks for saying that: Viruses can multiply in cells, so treatment wouldn't need to be given as often (at least 8 months at a time, whereas insulin injections are needed daily); and also that the gene will only be transcripted when it's needed in cells that produce insulin, whereas people need to carefully monitor and work out when to give insulin.

I think your second point would be credited, that it self regulates blood glucose

but in gene therapy the viruses inject the gene into the cells only once really and then they get destroyed, but the cells have the gene incorporated and so can keep producing insulin. So the viruses aren't really multiplying in the cells and keeping injecting the cells with DNA really.

[Ps3SuperSRG]

For the answer to why one of the huntingdon sufferers only had one band,i put that there could 2 bands of the same length so they overlap?
Im sure my teacher once said something about this. Ideas guys?

This was posted from The Student Room's Android App on my GT-I9100

[doubtful_dee]

(Original post by Ps3SuperSRG)
i put the neurotransmitter wasn't resynthesized so the synapse became 'fatigued' as the synaptic vesicles were empty.

This was posted from The Student Room's Android App on my GT-I9100

I don't think that's right because resynthesis implies that acetylcholine was broken down in the first place and that's the whole point of the question. I might be wrong though xx

[whc23]

(Original post by ZeeBurb)
Some of your answers are worded in a way which may not get marks, e.g peak of oestrogen just before LH peak,
you would probably want to say rapid increase of LH conc shortly after increase in oestrogen conc.
And things like that.

Also your implanon answer would only get 0/1/2 marks I think, the mucus stuff is not on the spec... you would probably have to talk about how progesterone inhibits FSH and LH, so low FSH conc and the follicle does not develop, no oestrogen secreted from developing follicle so lining of endometrium can not build up and no FSH/LH surge associated with high conc oestrogen above the critical level so no ovulation, egg can not be fertilised.

4a) you need to talk about chemoreceptors in the walls of the aorta/carotid artery and also the medulla oblongata, so you'd get 1 mark

5bi) You should talk about how successfully transformed egg cells would glow green in fluorescent light, so it would act as a gene marker

5ci) not sure if they'd have that on the spec, I talked about damage to DNA in the nucleus during transplantation leading to embryo not developing fully. Your answer would suggest it would be impossible to get live births from this method.

6a) include gluconeogenesis

6biii) in this evaluate question you should include a point to support it, like it does keep blood glucose low for quite a long time
I don't think the diet suggestion is strong, I'd talk about how gene therapy would need to be repeated as the cells die, and the cost of such treatment/secondary immune response risks of it not working

8bi) not PCR product, say it moves least far in the gel and is therefore longest fragment, most repeats

8biii) wouldn't 1 band mean you are heterozygous not homozygous for the allele with the repeats

9e) I said that answer, but people have also said that choose a bull which suffers from heat stress less

9g) Talk about variation due to mutation so some individuals will have the lactose tolerance allele and some will not,
then increased reproductive success of individuals with the advantageous lactose tolerance allele in these countries


My answers are more AQA markscheme like

Good comments . As I said, my answers are not necessarily the only ones, and I cannot guarantee that they will correspond to the official AQA markscheme until it is eventually published.

A comment about your point 9g). Since we are told that infants can digest lactose, it suggests that all individuals have the lactose tolerance gene. Thus the mutations that might arise for natural selection will be those that maintain expression of lactase beyond childhood.

http://cambridgeacademic.blogspot.co.uk/

[laughingbagel]

(Original post by ZeeBurb)
I think your second point would be credited, that it self regulates blood glucose

but in gene therapy the viruses inject the gene into the cells only once really and then they get destroyed, but the cells have the gene incorporated and so can keep producing insulin. So the viruses aren't really multiplying in the cells and keeping injecting the cells with DNA really.

But it frequently came up as an answer on the legacy paper.

4cii January 2009: "Give one reason for using a virus to transfer genes into cells."

Mark scheme:
targets cells;
replicates (in cells);

[sanaindaclub]

Mind went blank for the essay! Didnt write ANYTHING about DNA or receptors.
Only wrote about:

Transcriptional factors
Ribosomes
Joints
Enzymes + Inhibitors
Plasma membrane

Possible to get 10/16 from that?

[laughingbagel]

(Original post by sanaindaclub)
Mind went blank for the essay! Didnt write ANYTHING about DNA or receptors.
Only wrote about:

Transcriptional factors
Ribosomes
Joints
Enzymes + Inhibitors
Plasma membrane

Possible to get 10/16 from that?

Someone correct me if I'm wrong, but I think the 16 content marks are independent of the breadth ones - so if you talked about three of those topics really well, with lots of scientific terminology, then you can still get high in the content marks, and then only drop one in the breadth section?

[sanaindaclub]

(Original post by laughingbagel)
Someone correct me if I'm wrong, but I think the 16 content marks are independent of the breadth ones - so if you talked about three of those topics really well, with lots of scientific terminology, then you can still get high in the content marks, and then only drop one in the breadth section?

Hope so. REALLY annoyed at myself. Had 10 minutes to spare, where I could have written atleast another paragraph, but my mind went blank! Receptors, DNA structure, DNA Probes, Promoter region etc...

[Backchatgirl]

(Original post by RTJP)
I got the IAA question wrong too :'( but overall it went ok, I chose the shapes essay and I think that went ok

I just don't understand how you could do shapes, my mind went blank for that :L I'm sure you've don't good though

(Original post by RTJP)
No it was only 62 for an A last year, 63 could be right but 70 will be far too high

I hope you're right, I don't know much about UMS grade boundaries and 63 would be great (I'm thinking I've lost 20 marks thereabouts, but I've not counted 'officially')

[laughingbagel]

(Original post by sanaindaclub)
Hope so. REALLY annoyed at myself. Had 10 minutes to spare, where I could have written atleast another paragraph, but my mind went blank! Receptors, DNA structure, DNA Probes, Promoter region etc...

I did something similar. I only wrote about enzymes, receptors, inhibitors and transport proteins in any sizable depth, and then quickly thought of sex organs in the last minute. But I still managed to write about 6 pages, because I really went into depth about all of those topics. For example, I listed about 8 enzymes and explained what each of them did in certain reactions - covering lots of topics, like respiration, cell division, protein synthesis, homeostasis, muscle contraction, neurotransmission, the digestive system, photosynthesis etc.

[sanaindaclub]

(Original post by laughingbagel)
I did something similar. I only wrote about enzymes, receptors, inhibitors and transport proteins in any sizable depth, and then quickly thought of sex organs in the last minute. But I still managed to write about 6 pages, because I really went into depth about all of those topics. For example, I listed about 8 enzymes and explained what each of them did in certain reactions - covering lots of topics, like respiration, cell division, protein synthesis, homeostasis, muscle contraction, neurotransmission, the digestive system, photosynthesis etc.

Lol, I thought of sex organs too, but couldnt think of a way to put it ino tactfully!

[najd5]

(Original post by Ps3SuperSRG)
For the answer to why one of the huntingdon sufferers only had one band,i put that there could 2 bands of the same length so they overlap?
Im sure my teacher once said something about this. Ideas guys?

This was posted from The Student Room's Android App on my GT-I9100

I talked about partial digestion

[mindlessvandalism]

(Original post by Ps3SuperSRG)
For the answer to why one of the huntingdon sufferers only had one band,i put that there could 2 bands of the same length so they overlap?
Im sure my teacher once said something about this. Ideas guys?

This was posted from The Student Room's Android App on my GT-I9100

I'm sure on the paper that it said the diagram wasn't the entire gel electrophoresis, some of it was cut shorter for the purpose of the diagram so I think if it was the entire gel it would of shown two bands but just the last one much further down, which meant that the answer was still k

[Yosemite80]

would i lose a lot pf marks on the bacteria essay if i talked about

carbon cycle
nitrogen cycle, mutualistic and free-living bacteria, farmers growing legumes to replenish soil nitrogen
in vivo gene cloning and touched on fermenter usage
horizontal gene transmission and antibiotic resistance if you let bacteria with resistant genes escape from your gene cloning
cholera, effect, consequence and treatment
lactose intolerance and its humorous but serious effects
ruminants like cows and sheep and mutualistic relationship with bacteria in stomach
wrote a sentence mentioning mrsa and other bacterial diseases and talked briefly about mrsa being a superbug since it's resistant to methicillin which is a very strong antibiotic

tuberculosis, method of transmission BUT mixed it up with fibrosis when i talked about how it affects lungs, and i forgot to mention eutrophication completely...

im quite nervous about results of this exam because aqa makes unpredictable mark schemes and I need an A in this paper at the very least

[NinjaRikki]

Everyone, just want to ask a question. You know the microscope question, there seems to be answers of either magnification 3046 or 30455.

I personally put 30455, because one sarcomere= 6.7cm = 67mm = 67000micrometres.

Hence magnification = 67000/2.2 = 30455 as enlargement divided by actual.

Therefore, isnt this the right answer?

[marijuana]

(Original post by sanaindaclub)
Mind went blank for the essay! Didnt write ANYTHING about DNA or receptors.
Only wrote about:

Transcriptional factors
Ribosomes
Joints
Enzymes + Inhibitors
Plasma membrane

Possible to get 10/16 from that?

It would depend how you linked it back to the title , but I think 4 points with one out of spec (joints) should get you 10 or more.

[salad_fingers]

(Original post by Ps3SuperSRG)
For the answer to why one of the huntingdon sufferers only had one band,i put that there could 2 bands of the same length so they overlap?
Im sure my teacher once said something about this. Ideas guys?

This was posted from The Student Room's Android App on my GT-I9100

Why didn't I think of that?

[JJMick]

(Original post by NinjaRikki)
Everyone, just want to ask a question. You know the microscope question, there seems to be answers of either magnification 3046 or 30455.

I personally put 30455, because one sarcomere= 6.7cm = 67mm = 67000micrometres.

Hence magnification = 67000/2.2 = 30455 as enlargement divided by actual.

Therefore, isnt this the right answer?

Correct.