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AQA BIOL5 ~ 17th June 2013 ~ A2 Biology

Reply 1980

For part a (i) how will it make 2 fragments if its only digested at one site? Because its a plasmid surely it will only form one fragment?

There's already a restriction site in the plasmid, as seen in the diagram, so the DNA must also have one so there are two places where it's cut, sorry I didn't mention that bit :smile:

Reply 1981

JoshL123

2

Guys, do you think all of the old essays have a potential of coming up? It just feels that some of them are just too narrow :/

Reply 1982

F1's Finest

21

Original post by JoshL123

Guys, do you think all of the old essays have a potential of coming up? It just feels that some of them are just too narrow :/

I doubt the essays from the actual past papers (for the current spec) would come up. But don't count it out!

Reply 1983

JoshL123

2

Original post by James A

I doubt the essays from the actual past papers (for the current spec) would come up. But don't count it out!

I was thinking in relation to the old spec essays :/

Reply 1984

krane

9

Am i right in thinking that we only have 3 past papers and a specimen paper? :s-smilie:

Also dreading the fact that this exam is on the same day as edexcel psychology, makes the whole thing a lot harder!

Reply 1985

F1's Finest

21

Original post by JoshL123

I was thinking in relation to the old spec essays :/

meh, it could be!

What sort of titles are you referring to? I just skim the papers for the questions, but I don't look at the essay questions.

Reply 1986

ilanagrand

anyone got an essay on the important of water?

Reply 1987

JoshL123

2

Original post by James A

meh, it could be!

What sort of titles are you referring to? I just skim the papers for the questions, but I don't look at the essay questions.

Stuff on, fore example, How amino acids get from protein to a persons food, and the role of pigments in organisms. I swear that these kind of essays hold little 'synoptic' elemnets :/

Reply 1988

F1's Finest

21

Original post by JoshL123

Stuff on, fore example, How amino acids get from protein to a persons food, and the role of pigments in organisms. I swear that these kind of essays hold little 'synoptic' elemnets :/

Damn

The thing with those questions is that you are a little restricted on what you can talk about.

The first one about amino acids you mentioned, we can only talk about:

polypeptides
digestion (processes involved)
Hydrolysis

That's about it.

IF you look at the current spec questions though, they have questions where there are many topics you can bring in. Like the recent one about shapes and fitting together, there's alot you can talk about from our spec (and of course, bring in some off topic stuff).

Also, remember that the old spec has different topics that the kids that sat the exams back then, had to learn.

So they will have to ask us a question, which has a common theme amongst the entire A-Level spec that we learnt.

Reply 1989

starfish232

Hi, could someone please just help me with some questions I have about muscle contraction:

1. Is the sliding filament theory to do with describing the process of muscle contraction or is to do with changes in the sarcomere when muscle contraction happens?
2. In Q2b of the June 2012 paper, the answer is between 29545-30455 but I got an answer of 25909 and I'm not exactly sure what the image measurement is suppose to be.
I got 114(mm) x 1000 / 4.4 which equaled to about 25909.

Thanks
http://filestore.aqa.org.uk/subjects...W-MS-JUN12.PDF
http://filestore.aqa.org.uk/subjects...5-QP-JUN12.PDF

Reply 1990

currydud

Original post by starfish232

Hi, could someone please just help me with some questions I have about muscle contraction:

1. Is the sliding filament theory to do with describing the process of muscle contraction or is to do with changes in the sarcomere when muscle contraction happens?
2. In Q2b of the June 2012 paper, the answer is between 29545-30455 but I got an answer of 25909 and I'm not exactly sure what the image measurement is suppose to be.
I got 114(mm) x 1000 / 4.4 which equaled to about 25909.

Thanks
http://filestore.aqa.org.uk/subjects...W-MS-JUN12.PDF
http://filestore.aqa.org.uk/subjects...5-QP-JUN12.PDF

1. its about the process of muscle contraction

2.I got the answer of 30455

magnification=image length/actual length
magnification=67000/2.2
=30454.545454..
=30455 :smile:

(edited 10 years ago)

Reply 1991

Tikara

guys, are there actin filaments inside a cell?

Reply 1992

currydud

Original post by Tikara

guys, are there actin filaments inside a cell?

yeah, a muscle cell

Reply 1993

Tikara

Original post by currydud

yeah, a muscle cell

I meant in non muscle cells sorry :rolleyes:

Reply 1994

samfreak

with regards to DNA sequencing and gel electrophoresis on page 268 it says "In this way the whole sequence of bases on the terminator nucleotides was found to be AGCTTGAC and this is the sequence on one of the strands of the newly formed DNA." i thought that it was the sequence of the DNA we we originally had that we were trying to find though and not the sequence of the terminator nucleotides. Therefore the sequence we would be trying to find would be the opposite bases to the terminator nucleotide sequence?

Reply 1995

Tikara

Original post by currydud

yeah, a muscle cell

I found out if anyones wondering - yeah they're found in non-muscle cells :P

Spoiler

Reply 1996

havana-affair

1

regarding gene therapy,

does both gene replacement and gene supplementation fall under somatic-cell gene therapy
and germ-line therapy is a separate thing just for fertilized eggs?

Reply 1997

starfish232

Original post by currydud

1. its about the process of muscle contraction

2.I got the answer of 30455

magnification=image length/actual length
magnification=67000/2.2
=30454.545454..
=30455 :smile:

oh ok thanks.

I got confused since it said the whole diagram rather than just one sarcomere. Also, think my measuring is wrong because the question was in another pack rather in the exam paper it's originally from so size might be smaller of the diagram.

Reply 1998

starfish232

Original post by havana-affair

regarding gene therapy,

does both gene replacement and gene supplementation fall under somatic-cell gene therapy
and germ-line therapy is a separate thing just for fertilized eggs?