OCR AS Biology (F211) - Jan 2013.

Hi

* The left and right atria are both thinner than the right and left ventricles because they have to contract to push blood to a relatively short distance and so not a very high pressure is needed.

* The right ventricle is thinner than the left ventricle because it has to contract to push blood to the respiring cells of the tissues in the lungs, and because they are delicate a lower blood pressure is required than the left ventricle.

* The left ventricle is thicker than the right ventricle because it has to contract to push blood to a further distance than the left atria and the left ventricle. Therefore, a higher blood pressure is required due to this difference in distance.

Yep.

What is the function of :

a) Glycoproteins (1)
b) Glycolipids (1)
c) Cholestrol (1)

Suggest the precautions that should be taken before using the spirometer apparatus. (3 marks)

Explain why multi cellular organisms are in need of a transport system (3 marks)

Any tips on how to revise for this exam efficiently? How are most people revising here, any techniques?

I have three textbooks:

http://www.amazon.co.uk/Biology-Student-Book-Exam-CD-ROM/dp/0435691805/ref=sr_1_1?ie=UTF8&qid=1355085797&sr=8-1

http://www.amazon.co.uk/AS-Level-Biology-Complete-Revision-Practice/dp/1847621228/ref=sr_1_2?ie=UTF8&qid=1355085797&sr=8-2

http://www.amazon.co.uk/Biology-OCR-Cambridge-Advanced-Sciences/dp/0521717639/ref=sr_1_5?ie=UTF8&qid=1355085797&sr=8-5

I have the specification and looking at each point in as much detail as the 3 textbooks allow and I'm just making revision notes as I go through.

I might start getting flashcards and writing definitions on them and get someone else to ask me questions etc. as it always seems to help for me.
I would advise trying to teach someone else somethings as it really helps for me.....

First question:-
A. Glycoproteins can act as a cell signalling point for the cell.
B. Same as Glycoproteins.
C. Provides structure and rigidity to the plasma membrane.

Second question:-


Third question:-
Multi-cellular organisms tend to have a low surface area to volume ratio. Therefore, for respiring cells to have a supply of materials such as oxygen and glucose to metabolise a transport system, a network of blood vessels is required. Whilst the transport system provides cells with essential materials for respiration and other processes, it also removes waste products and usually transports them to tissues capable of handling them.

I think the first bit is correct.

2nd question:

I think for this question you could get 2/3 because you mentioned checking the health of the volunteer and you mentioned that it is important to check that the soda lime is working. Mark scheme below;

1 check health of volunteer ;
2 oxygen used ; 3 new / sterilised / disinfected , mouthpiece (for each volunteer); 4 idea of: soda lime working ; 5 sufficient oxygen in chamber ; 6 water level not too high / water must not enter tubes ; 7 ensure valves working correctly ;

Answer to third question;
reference to size increasing / increase implied / large;
need for systems faster than diffusion / diffusion too slow / AW;
central regions further from surface / diffusion path too long /AW;
ref to separation of different specialised areas;
correct ref to surface area to volume;
ref to movement of a named requirement; A nutrients, waste, gases
but R food
(may) have high metabolic rates / more active;

From this we can see that for 3 marks you could have put:

* Large multicellulal organisms have a small surface area to volume ratio, this means that diffusion is too slow.

* The cells at the center of the organims would not receive oxygen and nutrients because the diffusion distance is too far.

* Large multicellular organisms have a high metabolic activity so they have a high demand for oxygen for respiration.

Hi

revision?

yeah sure, do you want to do f211 or f212?

Ill ask you F211 and you ask me F212

State the function of golgi apparatous (2)

Function of the golgi apparatus is to put proteins into vesicles and sometimes modify these proteins.

Q: Outline the process of phagocytosis. 4 marks

correct



Phagocyte attaches to bacterium. Phagocyte has membrane bound cell surface receptors and the receptor is complementary to shape of antigen. receptor has specific shapee and cause antigen to bind for phagocytosis to occur. bacterium is engulfed and releases lysosome to breakdown bacteria to form useful susbstances such as amino acids. Formation of phagosome. Bacteria is digested in cytoplasm and forms useful molecule such as amino acids and moves by diffusion.

Correct.

Suggest why liver cell has lots of mitochondria (2)

Lots of mitochondria are required so that aerobic respiration can take place and produce ATP. This Atp is vital in the liver cell for its many functions, one being to convert glycogen into glucose.

Compare the structure of protoctist and fungi.

correct and could state as it carries high metabolic processes


fungi = cell wall made of chitin , growth of reproductive hyphae and mass of hyphae is mycelium, multicellular

protoctist- unicellular , have nucleus, some have flagella, a good example is amobea and have large surface area to volume ratio and have thin walls for easy diffusion

I have two of the text books you are using. Where can I get the full specification from?
And yeah I might try and use flashcards and see how that works for me.

how the hell are you getting all these in depth answers? do we HAVE to know this?

how the hell are you getting all these in depth answers? do we HAVE to know this?