AQA BIOL5 ~ 17th June 2013 ~ A2 Biology Watch
I need 50ums more for my overall B grade. I have the grades from all the other modules.So anyone guess roughly how many marks 50ums is likely to be?
Complementary T cells bind to antigen expressed on phagocyte
Stimulates the division of T cells by mitosis. Develope to form memory cells and cytotoxic T cells that produce a toxin that make holes in membrane of pathogen.
Also divide into T helper cells.
B cells then take up antigen of pathogen and express it on surface
T helper cell binds to it activating the B cells which now divide by mitosis to form memory B cells and plasma B cells.
Plasma cells produce Y shaped antibodies and complementary to antigen and form antigen antibody complexes.
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I'm a bit confused with gel electrophoreisis, I understand the further the fragments move, the smaller they but i'm a but confused about the terminator base thing, is is related to this or completely different?
positive feedback: oestrogen stimulates gland to release LH and FSH which further stimulates the ovaries to release oestrogen
negative feedback: LH stimulates the corpus luteum to develop which produces progesterone. progesterone inhibits further release of LH
As the follicle grows more, by around day 10 higher levels of oestrogen is produced, this causes the inhibition to be reversed, so now oestrogen stimulates FSH and LH (positive feedback)
Later on, after ovulation the corpus leutum (formed by LH) secretes progesterone, progesterone inhibits FSH and LH (negative feedback)