AQA BIOL5 Biology Unit 5 Exam - 22nd June 2011

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Hi everyone! First of all, good luck for tomorrow!
Second of all, can someone please explain genetic fingerprinting to me?
Thirdly.. what exactly are DNA primers?

Thanks!

Reply 1621

NRican

Original post by Tericon

Possibilites at a glanceATP

Variation

Cycles

Proteins/Carbs

Enzymes

They haven't been up for a bit...

Wasn't variation in the Spec paper ? :s-smilie:

Reply 1622

M | k e

Original post by addvic

you need to get an A overall 480/600 i think.. then out of the 480+ marks you've got, 270 of them need to be from A2 units, so unit4, unit5 and unit6. hope that makes sense!
also, i think the spec paper answers are wrong too! Na+ moves in and K+ moves out.

Ok then.

Yeah that's what I thought, was like whaa have I learnt it backwards :P. gdgd ^_^

Reply 1623

vickidougal

1. Lipids in health and disease.
2. Genes and diversity.
3. The ways in which different organisms become adapted to their environments. 4. Coordination within organisms and between organisms and their environments.
5. Discuss how scientists collect, analyse and interpret biological data.
6. A space probe brought back samples of life-forms from a hot, dry planet with
low atmospheric oxygen but high carbon dioxide concentrations. Describe the
adaptations these life-forms would have in order to survive these conditions.
7. The physiological impact of lifestyle on health.
8. The impact of human activities on the diversity of animals and plants.
9. Receptors and their roles in coordination.
10. The pathways of synthesis of carbohydrates from atmospheric carbon dioxide.
12. Perform a critical analysis of methods used to collect biological data.
13. Stem cells research offers a great number of potential benefits to humans. It
also comes with many down sides. Write a balanced account of the ways in
which stem cells could and should be used to benefit humans.
14. Discuss the benefits and draw backs of gene cloning technologies.

Reply 1624

Flux_Pav

need 66 marks for an A* going by june 2010 UMS calculator

Reply 1625

Tericon

Original post by NRican

Wasn't variation in the Spec paper ? :s-smilie:

Yes it was :biggrin:

Reply 1626

kingsmod1

guys wat page was it wer they posted all the asnwers to the essays

Reply 1627

addvic

Original post by Flux_Pav

need 66 marks for an A* going by june 2010 UMS calculator

on aqa website if you click on administration then post results services then on the grade boundaries link it gives you the raw marks you needed for each grade for each exam.

Reply 1628

NRican

Original post by Tericon

Yes it was :biggrin:

So unlikely to come up right? even though I hope it does as it's pretty easy.

Reply 1629

Nat1986

Original post by Sparkly-Star

NT book, chapter 12, p.211 does anyone get 3.c? I don't understand it. :frown:

I agree, this question is really hard. and thats even with the answer!
it wants you to separate the 2 parts of info..look at the muscle and adrenaline first then move onto the glucagon. do you have the answers?

Reply 1630

Abby :)

Sooo what are predictions for this exam please?
I havnt really looked through past papers for patterns etc, so could appreciate everyones thoughts?

Not TOO scared for the essay.... since ive resat 3 out of the 4 units this month. :tongue:

So most of the course is still fresh in my mind!

Reply 1631

M | k e

Original post by Zozza93

Hi everyone! First of all, good luck for tomorrow!
Second of all, can someone please explain genetic fingerprinting to me?
Thirdly.. what exactly are DNA primers?

Thanks!

DNA primers are just short strands of DNA that are complementary to the start of a target gene. They're used in Polymerase Chain Reaction (PCR) to bind to the start of the target gene, firstly to stop the 2 DNA strands of target gene just re-joining, and secondly because DNA polymerase needs a double strand to start from to work for the rest of PCR :tongue:

.

Well that's off the top of my head, pretty sure it's right though :smile:

.

And DNA fingerprinting is using the non-coding repeating sequences, in introns, to compare their lengths between different people. These repeating sequences will occur at different parts of the DNA, and chances of someone having same length as even one other person is extremely slim, but chances of them having same length at more than one part of the DNA is even slimmer. So these sequences are taken out from the DNA and replicated using PCR. All these fragments are labelled (e.g add fluorescence to them). They then undergo electrophoresis, where they're placed in a conductive gel at one end. Then an electrical current is passed through, and because DNA is negative they move towards the positive electrode at the far end of the gel. The smaller the repeating sequence length was, the further it will be able to travel. Then using UV light you can see bands of the DNA fragments, and compare how far they moved along the gel to the length of the repeating sequences.

Reply 1632

pip91uk

Quick question about 'sticky ends'. I know that every restriction enzyme will only recognise a specific sequence, but within that recognition sequence, will it always cut in the same place? Basically, I'm looking at page 248 in NT textbook and it states that an enzyme (HindlIII) has a 6bp recognition sequence, but in the diagram there are only 4 bases exposed on each sticky end. I always thought the enzyme cut at the start/end of the recognition site. :confused:

Reply 1633

daddeee

Hi guys

Sorry if its already been written but could anybody place some good guesses as to whats going to come up tomorrow.
I have a philosophy exam straight before and I need to revise for both: somethings are going to have to give!

I can already see a rerun of what happened in january.... :frown:

Reply 1634

Carpet21

Crapcrapcrapcrapcrapcrap.
The realisation of how little I know is really starting to hit me.

On a side note....crap.

Reply 1635

Somali-Pir8

just did the specimen paper
does anyone have any clue as to what the grade boundaries are

Reply 1636

Tericon

Original post by NRican

So unlikely to come up right? even though I hope it does as it's pretty easy.

Well its only popped up twice, specimen and in Jan 2004... whereas something like transport/movement (diffusion osmosis etc) has come up 5 times overall.

A prime example is in June 2007, one essay was 'Movements inside cells'.

In June 2008, one of the essays was 'The part played by the movement of substances across cell membranes on the functioning of different organ systems'.

A little different I know, but largely similar, just goes to show sometimes (cough) AQA are very mean.