For the HIV question, I didn't talk about mRNA. I said that there is a change in the amino acid sequence, leading to the bonding in the tertiary structure to change. So differed wbu bonds are formed. As a result, the quarterny structure changes in a way that the receptor is no longer complimentary to the antigens of the HIV. As a result it is no longer functional. I didn't talk about splicing or translation. Would I get half the marks or not?

for 4 marks there'll be loads of points you can have. as long as you have 4 of them you should be fine. amino acid sequence, change in bonding, change in tertiary structure and therefore change in active site. You should have 4 points there but idk how picky mark scheme is

Reply 964

zigocarn

What did you guys write about the question why the scientists drew the conclusion, it was about HIV and natural selection.

Reply 965

rafiuddin

Original post by Harris07826

what was the area around the letters

dont remember the exact areas, but the amount it was bigger by was around 2.9 (should be a range of roughly 2.5-3.5 since it's hard to get an exact diameter)

Reply 966

rayofsunshine98

Well I've failed biology now

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Reply 967

Harris07826

the white area around the letters.
what was it called
it was the first part of that question

Reply 968

rafiuddin

Original post by zigocarn

What did you guys write about the question why the scientists drew the conclusion, it was about HIV and natural selection.

people with HIV can still have babies (despite the parent not being naturally selected)
people with HIV can survive under medical/quarantine conditions (probs wrong)

Reply 969

rafiuddin

Original post by Harris07826

the white area around the letters.
what was it called
it was the first part of that question

clear zones

Reply 970

memoriial

Original post by rafiuddin

got 3.86 ish

I got 1.5 to 4 which I doubled out to 3 to 8. I have no clue if that's right, my maths is terrible, but it seemed to fit while I was working it out.

Reply 971

G.name

Original post by rafiuddin

ratio one, you don't actually get the same if you use area, which is what was supposed to be used afaik,

seasonal change one - i wrote about how it'll flower in time for spring and that cold temps usually means rain/snow - water used in photosynthesis, also brings in minerals and vitamins from soil (second part is probably wrong)

everything else seems good

Nice. I'm only worried that I wont get a lot of marks. These mark schemes seem absurdly picky.

For seasonal change, flowering makes sense. It sound like a standard answer. Mine extrapolated a bit wrongly.

Ratios. Of course! because you square the radii. Damn. That was tricky.

Can you remember any more difficult ones. And thanks for the vote of confidence! :smile:

What do you think GB will be?

Reply 972

kiwifruit99

Unofficial mark scheme anyone?

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Reply 973

laney1999

Why are people talking about enzymes 😢

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Reply 974

rafiuddin

Original post by memoriial

I got 1.5 to 4 which I doubled out to 3 to 8. I have no clue if that's right, my maths is terrible, but it seemed to fit while I was working it out.

for ratios, you're supposed to get something:1
so doubling it doesn't work since none of your numbers is a 1

Reply 975

ShenelW

Original post by rafiuddin

from the answers already written in this thread

it was something like phospates are used in the phospholipid bilayer, ATP, DNA, RNA, so more of it means more of the things mentioned, showing growth

something like that

Sorry I meant for the one about seasonal changes?

Reply 976

rafiuddin

Original post by G.name

What do you think GB will be?

i'm gonna go out on a limb and say around 58/57 for A
52 for B
(don't care about anything below this :colonhash:

)

Reply 977

memoriial

Original post by rafiuddin

for ratios, you're supposed to get something:1
so doubling it doesn't work since none of your numbers is a 1

Never heard that rule for ratios. I only studied maths to GCSE but as far as I'm aware 3:8 is a legitimate ratio.

Reply 978

Enderbat1999

it wasnt half bad this paper those 5 markers were so nice

Reply 979

rafiuddin

Original post by ShenelW

Sorry I meant for the one about seasonal changes?

it'll flower in time for spring for easier pollination

(this part probs wrong) - cold temps usually means rain/snow, water taken in and stored for photosynthesis later on, water also contains minerals and vitamins for growth etc