The OFFICIAL OCR June 2013 AS Biology F212 Exam Thread.

um, did no one else go completely blank on the collagen question, the potato blight question and the bloody squireeelllss?! what the hell man :'(
and also for the selective breeding of the crops can someone just tell me what they wrote so that i dont cry myself to sleep tonight?
thanks

DEM SQUIRRELS! haha, bro i can tell you what i wrote
For the collagen :-
1)It is a fibrous protein
2)It is make up of alpha-C1-C4 Glycosidic Bonds which form long polypeptide chains
3) it has cross-links made of hydrogen bonds between the fibres
4) It is strong and flexible
5) this allows the artery to recoil
6) It is also insolube , which means it doesn't reduce the water potential of the cells.

the Selective breeding question: -
1) Farmers select the plants that have survived and they allow them to reproduce.
2)They will transfer the Resistive Allele to the offspring
3)They then breed the offspring over generations, creating a fully resistive species
4) to improve, and not cause this destruction of plant, they need to increase the gene pool which can be done by bringing in different types of potatoes, or creating cross-programmes where you bring in types of potatoe from all over the world to increase the gene pool.

HOPE THIS HELPS!!!!!

didnt we have to talk about the fact tht it is made up of 3 polypeptide chains etc
and that it is a left handed helix sturcture as well

you know the one where we had to draw the hydrogen bonds between the bases
i just did a dotted line between all the bases and labelled it hygroden bond

would that be right?

didnt we have to talk about the fact tht it is made up of 3 polypeptide chains etc
and that it is a left handed helix sturcture as well

any thoughts on the grade boundaries?

what did you guys put for the phagocyte one?
wasit B? or C?


also the process of phagocytosis
i think i misunderstood teh question
i spoke briefly aout the enveloping of the phagocyte membrane inward forming a phagosome vacuole and i mentioned the enzymes digesting the pathogen
but i went onto to talk about antigen presenting cells and the rest of the immune response :c


any thoughts on the grade boundaries?

DEM SQUIRRELS! haha, bro i can tell you what i wrote
For the collagen :-
1)It is a fibrous protein
2)It is make up of alpha-C1-C4 Glycosidic Bonds which form long polypeptide chains
3) it has cross-links made of hydrogen bonds between the fibres
4) It is strong and flexible
5) this allows the artery to recoil
6) It is also insolube , which means it doesn't reduce the water potential of the cells.

the Selective breeding question: -
1) Farmers select the plants that have survived and they allow them to reproduce.
2)They will transfer the Resistive Allele to the offspring
3)They then breed the offspring over generations, creating a fully resistive species
4) to improve, and not cause this destruction of plant, they need to increase the gene pool which can be done by bringing in different types of potatoes, or creating cross-programmes where you bring in types of potatoe from all over the world to increase the gene pool.

HOPE THIS HELPS!!!!!