Biology AS AQA

I really don't get what we need to know on T-Cells and B-Cells. Any help would be greatly appreciated, thanks in advance

Basically the T cells are white blood cells that have matured in the thymus gland, they are a secondary response and a cell mediated. This means that they deal with the cells that have come in contact with the pathogen I.e the phagocytes. The T cells make specific receptors to fit the antigens that the body cell has presented on their own cell surface membrane to form a antigen-receptor complex. After that, the T cells destroy the body cell by piercing holes into the cell surface membrane which distrupts the integrity of the cell and so it can't withstand pressures of osmosis. The B cells are also a secondary response but this is more long term as the B cells come across the pathogen the T helper cells bind to the B cells activating them to divide by mitosis into plasma cells (these produce antibodies specific to the pathogens own antigens) the B cells also produce memory cells that circulate in the blood that when they come in contact with the pathogen in the future, it can rapidly divide by mitosis into more plasma and memory cells. This is known as humoral immunity as it is in the blood. Hope this helps!

thank you that was very helpful! Absolute lifesaver, I can go into that exam feeling confident now hahaha

Feeling ready for the exam although I haven't revised, the only bit I find confusing at all is the immunology section and remembering parts of the heart, so far I've been getting 50-55/60 on the mocks so I'm confident

Feeling ready for the exam although I haven't revised, the only bit I find confusing at all is the immunology section and remembering parts of the heart, so far I've been getting 50-55/60 on the mocks so I'm confident

Take it from an A2 student who happens to be re-sitting this module.... REVISE. You won't make it through A2 without revising, Even if you can scrape through AS without.
My teachers always told me three hours a day 5 days a week. Although as exams approach its more 4 hours a day 7 days a week.

My sister does A2 and I have seen the content, it is so much harder!and yeah my teachers say the same, I would be so much more nervous if I didn't revise! Are you only resitting unit one? Good luck

Has anyone got any idea of what the 5 markers are likely to be?

The sodium- potassium pump is about moving sodium and potassium ions across the cell membrane using active transport.
The sodium- potassium pump is an example of when a molecule or ion is being moved into a cell at the same time as a different one is being removed from it.

In the pump, sodium ions are actively removed from the cell while potassium ions are actively taken in from the surroundings. This process is essential to a number of important processes in the organism, such as the creation of nerve impulses.


i haven't been taught that much about it but that is what i know, there is also another part to it, involving glucose, about the role of active transport in absorption, if you'd like me to explain the stages of that?

it's all so confusing o_0

Omg just everything. I am dreading unit 2 even more


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Anyone have any predictions for tomorrow?

Take it from an A2 student who happens to be re-sitting this module.... REVISE. You won't make it through A2 without revising, Even if you can scrape through AS without.
My teachers always told me three hours a day 5 days a week. Although as exams approach its more 4 hours a day 7 days a week.

Wow that's really good! How do you get such good marks without revising!?

Haha people always say that but I'm just good at biology, I can't do the same in other subjects really