Edexcel A2 Biology exams (6BIO4) 25th January 2012 exam discussion

Anyone know a site where i can find 2008/2009 papers? Tried Edexcel but they don't have them.

The T-Helpers are only activated once then come into contact with antigens presented by a macrophage. Without the macrophage (as an APC), the T-helper cell couldn't produce a specific type of antibodies (by undergoing the effector response).

Does that clear things up? It's easier to think of it in my head, than get it down in words.

Macrophages in the specific response are also involved in the differentiation of T helper cells and B cells, right?

I remember you from the summer 2011 bio thread(s) How did your results go?

that's because there are ony the Jan 10, 11 & Jun 10, 11 papers for our spec annoying right?

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Oh hiii!
I did pretty well last year got AAB, and one of the A's was for Bio which I was quite surprised about Although I feel this year may be my downfall how did you get on last year?

I seem to remember doing 08/09 papers last year for AS. Maybe they were the old ones. Eh :/ There goes my revision plan for tonight.

How do you work out GPP???

For dummies

just done the jan 2011 paper 61/90 58 was an A* This exam might go ok, I hope.

Ok I will give this a shot

In non-specific immunity, macrophages perform phagocytosis as the antigens on the pathogen are recognised as 'non-self'. Macrophages engulf pathogens, forming a phagocytic vacuole, which is then digested by lysozymes. This normally occurs during inflammation and is non-specific to the antigens.

In the specific immune response, the macrophages perform phagocytosis and then present the antigens of the pathogen to become an antigen-presenting cell (APC). This then binds to a complementary CD4 receptor and releases cytokines to produce T helper and T memory cells that then stimulate clonal selection and produce antibodies specific to the antigen.

Damn... my finger hurt

what book do you use to revise from, the official revisions guide misses out some of this information. And any revision techniques.

i posted this earlier on this page there's a really good pdf with every point of the specification explained, and core practicals to remember are on the next page

http://www.thestudentroom.co.uk/showthread.php?t=1819039&page=25

hope that helps!

Your video (Gun and porK) always brings me entertainment when I'm on TSR! much love man!

i posted this earlier on this page there's a really good pdf with every point of the specification explained, and core practicals to remember are on the next page

http://www.thestudentroom.co.uk/showthread.php?t=1819039&page=25

hope that helps!

Thanks! I've had that pdf from before, but it still misses out some bits such as the role of macrophages in non-specific responses in detail. Is there anything else you use to extract information such as the text book/ cgp revision guide?