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AQA BIOL1 Biology Unit 1 Exam - 16th May 2011

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Reply 420

liviaaa

Original post by anna258

hahaa, another question too, if you don't mind...
How did you do QUESTION 5.b) from the same paper? :smile:

20cm3 = 1 mol

So

4cm3 = 0.2 mol (divide it by 5)

As there is 4cm3 of NaCl, there must be 16cm3 of water, to make it up ot 20 cm3.

Reply 421

RG1994

what do antibodies do? and whats the difference between an antibody and a pathogen and therfore why are they destroyed seperatly?

Reply 422

Stratos

I'm starting my revision now...

I was wondering whether we would have to discuss cytokines for the humoral immunity. Or is that a step to high for AS?

Reply 423

??????????????????

Original post by RG1994

what do antibodies do? and whats the difference between an antibody and a pathogen and therfore why are they destroyed seperatly?

Antibodies clump bacteria together by binding to the antigens. They then can't enter cells as they are too big to fit through the membranes. Also easier to ingest fo WBC.

Reply 424

RG1994

Original post by Stratos

I'm starting my revision now...

I was wondering whether we would have to discuss cytokines for the humoral immunity. Or is that a step to high for AS?

too high for unit 1

Reply 425

??????????????????

Original post by Stratos

I'm starting my revision now...

I was wondering whether we would have to discuss cytokines for the humoral immunity. Or is that a step to high for AS?

Ctyokines stimulate B-Cells right?
My teacher didn't know what they were when I asked. =.=

Reply 426

301lw

can someone please explain to me the different measurements we need to know? :smile:

e.g. how many um and nm there are in 1 mm

Reply 427

whiskeyinthejar

Would just like to wish everyone luck for tomorrow, don't panic when they inevitably ask us something we haven't been taught as such- read the question and use the knowledge you do have!

This will be the 3rd time I've sat unit 1, 3rd time lucky eh?!

Reply 428

RG1994

Original post by DoaaK

can someone please explain to me the different measurements we need to know? :smile:

e.g. how many um and nm there are in 1 mm

1 = 1km
1^-3 = 1mm
1^-6 =1um
1^19 =1nm

Reply 429

Ramin Gorji

Original post by whiskeyinthejar

Same here! Its annoying because its the easiest module yet I always end up doing worse than i thought :P

Reply 430

RG1994

Original post by RG1994

1 = 1km
1^-3 = 1mm
1^-6 =1um
1^-9 =1nm

sorry mistake there
1^-9 =1nm

Reply 431

301lw

Original post by RG1994

sorry mistake there
1^-9 =1nm

thankyou

so do i basically just add 000 each time?

so 1000 um = 1mm?

Reply 432

anna258

what does everyone think the hardest topic is for Unit 1?

Reply 433

hash007

Original post by liviaaa

It moves from roothair cell, to xylem by osmosis. Up the xylem by cohesion-tension, cappilarity or root pressure. NOT active transport - that requires ATP, and the xylem is made from dead cells.

--

Anyway this is AQA unit 1, not OCR unit 2. :tongue: