OCR Biology AS F211 May 2012

heya everyone im resitting unit 1 and doing unit 2
so stressful (((

Done any1 have the January 2012 F211 and F212 paper???
If yes can you please upload it

It's on here

http://www.thestudentroom.co.uk/showthread.php?t=1943168

I made this thread as I couldn't find a thread for the F211 paper being sat in May 2012.

How is everyone getting on with revision?

Revision is quite well, there are lots of logical questions from module 3, which I seemed to be getting wrong I find the questions relating to module 1 and 2 quite simple.

What is module 3? Plants?

It is biodiversity and evolution, it is simple for most people and easy marks to score, I seem to be an idiot in these type of questions. I prefer the normal technical answers. p

Can someone help me answer this:

Describe the stages of mitosis (6 marks)...

I'm having difficulty understanding this section so any help would be appreciated

Or even if someone could explaining it would be really helpful

Pre Mitosis: Interphase - DNA is replicated
Prophase:
-Chromosomes supercoil (shorten and thicken),
- nuclear envelope breaks down and disappears,
-centrioles split and move to opposite poles to form spindle

Metaphase:
- Chromosomes move to equator of spindle and attach to it by means of their centromere

Anaphase:
- Centromere splits and replicated chromatids separate
- spindle fibres shorten and thicken and pull sister chromatids away from each other to opposite poles

Telophase:
- As sister chromatids are pulled to opposite poles, a new nuclear envelope forms around each set
- Spindle fibres break down and disappear
- Chromosomes uncoil

Cytokinesis (different in animals and plants)
- Cell splits into 2, these are genetically identical to each other and to the parent cell as they have diploid number of chromosomes and so will perform the same function as parent

Okay thank you sooo much that would probably be 6/6

But btw could you mention that the chromatin condenses to visible chromosomes firstand then it supercoils
Or does condensing it and supercoiling basically mean the same thing?

Good question, im not quite sure, i think the supercoiling leads to its condensation, condense means thicken, and supercoil leads to thickening so I guess so, that maybe a "suggest" question in the paper loool