Biology: OCR GATEWAY 17/06 OFFICIAL THREAD

That exam was pretty bad, made some stupid mistakes, I hope grade boundaries are low like last year... Any unnofficial mark scheme?

That exam was pretty bad, made some stupid mistakes, I hope grade boundaries are low like last year... Any unnofficial mark scheme?

That was such a terrible exam I completely messed up

I think it was easier than Unit one but it was a little difficult, I agree.

It probably was, but everything i studied wasn't in there - no photosynthesis equations, no kidney nephron details, no disease stages, no structure of a leaf.

1) D Plasmolysed
2) Active transport is when ATP is used to change shape of the carrier molecule so minerals can be absorbed by roots against concentration gradient
Random question) Red seaweed absorbs most because red penetrates the sea water the least and is reflected by the seaweed meaning the colours it absorbs all penetrate further than the one it reflects...not sure I've explained this clearly
Random question) Szcheroy -6.25% - very dehydrated so muscles cannot work efficiently so Leroy finished race
Random question) Leroy's urine = greater volume because he was less dehydrated so less ADH released so less kidney tubules made more permeable to absorb water thus less water reabsorbed and more urine lost
Random question) Likelihood of osteoporosis (occurs due to lack of calcium) increases as age increases which makes bones more brittle
Random question) Old granny needs to increase her mass by 8kg
Random question) The bone marrow was the middle of the bone coloured in grey and the cartilage was any end of the bone with dots
Random question) For the four proteins: nitorgen, oxygen, hydrogen, carbon
B4 6 mark question) Dry soil = lack of water which decreases the rate of transpiration and photosynthesis as efficient photosynthesis cannot occur when there's lack of water. Strong winds increases the rate of transpiration because it maintains the concentration gradient as water vapor molecules are swept away. I'm not sure about this part but I said it decreases the rate of photosynthesis because the concentration of co2 surrounding the plant decreases which reduces the rate of diffusion. Low temperature decreases the rate of photosynthesis because the particles have less energy and decreases rate of transpiration as water particles have less energy to evaporate and diffuse out the stomata
Random question) Xylem transports minerals and water and phloem transports sugars and food
Random question) Temperature is reduced between 35 and 50 degrees for the landfill gas to ensure temperature is high enough to give fast rate of fermentation but the cost isn't too high to maintain the high temperature
Random question) Gene that cuts = restriction, Gene that repairs cut surfaces = DNA ligase
Random question) Important that same restriction enzymes are used so that DNA ligase can join the DNA and bacterial plasmid by complimentary base pairing ensuring the gene has been taken up
B5 6 mark question) A cut exposes platelets to the air which causes a series of chemical reactions. This eventually converts a soluble protein in the blood plasma to insoluble fibrin fibers which join together to form a clot. Aspirin/warfarin reduce the amount of platelets found in one specific area so less are exposed to the air if a cut occurs. Thus less fibrin fibers are formed preventing dangerous clotting. Cannot remember the graph part.
Random question) Does not prove global warming causes tree rings with greater width because other factors can increase temp
B6 6 mark question) In both as phytoplankton increases so does zooplankton. But in North Atlantic phytoplankton reaches maximum during March/April whereas in Arctic during June/July. This may be because temperature is higher during different months in the two areas so rate of photosynthesis increases at different times. Also, phytoplankton increases during August/September in North Atlantic but for Arctic it consistently decreases, perhaps greater light intensity in North Atlantic than Arctic so more photosynthesis. I am not sure about this question, that is just what I wrote.

For the strong wind in the six marker I said that it increases air movement but if too strong then too much water would be removed ? So it is higher transpiration but then not enough of the water is used ?

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can we have an unofficial markscheme?

That sounds more sensible than what I suggested.

I wrote Dna Ligase but then crossed out Dna. Would I still get a mark?