Ocr gateway biology UNNOFICIAL MARKSCHEME

How was the exam?

Answers not in order just in order of topics

B4

1)d and the cell is plasmolysed (it asked for cell not plant so flaccid/wilted might not be accepted) [2 marks]

2) amino acids, enzymes, genetic material/information?? Idk edit they meant name 4 minerals so that's nitrates, phosphates, magnesium and potassium [4 marks]

3) active transport is when substances are absorbed against a concentration gradient, opposite movement of diffusion, needs energy

4)red is usually absorbed by chlorophyll a and b so idk. I wrote they survive because pigment not reflected they have short wavelength?? Maybe lots of stomata or large surface area so they can get more light even at low depths??? Lots of chloroplasts??

5)[6 mark]

Low temp:

Decrease rate of photosynthesis
Decrease transpiration

Dry soil decrease photosynethesis (need water & minerals so slow growth)
Decrease transpiration no water to evaporate?

Strong wind means more air movement so increases transpiration
Strong winds increase photosynthesis idk I think lots of co2 maybe

6)xylem(water)and phloem(food substances) [4 marks]

7)wood can't take in o2 so won't rot because the microorganisms (decomposes) needed for decay can't respire and grow/reproduce

B5

1) cartilage at ends and bone marrow in the hollow shaft so the middle part

2)ball and socket allow rotation the hinge joint won't

3)there is no lubrication etc osteoporosis brittle and fragile bones lack of calcium

4)bypass surgery (I ticked heart assistant lool I forgot it said surgery they may allow idk cause it helps with recovery of heart attack :frown:

)
5)Old granny needs to increase her mass by 8kg

6) 6 mark

-Aspirin and warfarin are anticoagulant drugs
-reduce chance of thrombosis
-stops platelets
-graph is easy to view so will encourage him
- the dangerous clotting etc clearly decreases when the drugs are used (maybe give figures I did)
-warfarin reduces it drastically

7) group o has no a and b antigens and is anti a and b

8)small intestines are long
Have thin lining
Good capillary network
Villi (increase surface area) [2 marks]
9)Leroy -6.25% - very dehydrated so muscles cannot work efficiently so Leroy finished race
10)Leroy's urine = greater volume because he was less dehydrated so less ADH released so less kidney tubules are permeable to absorb water thus less water reabsorbed and more urine lost

B6

1)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

2)advantage doesn't produce a lot of co2 so less polluting
The methane is over 50% so easily burned good fuel
Disadvantage can't remember

3)Gene that cuts = restriction, Gene that repairs cut surfaces = DNA ligase

4)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

5) there will probably be a yes and a no

I wrote yes because there was an increase between 1000 years and more at present we are increasing ozone depletion ns I have reasons. So it's hotter and that's when the width increased
Or
Does not prove global warming causes tree rings with greater width because other factors can increase temp

6)50 and ph 5

7) immobilised enzymes have constant oh so easier to control use etc idk they can be reused and taken out easily of reaction

Free enzymes had a higher activity so more sugar production

8)fructose and glucose useful to increase flavour so more consumers/profit sugar is addictive more people will buy products

9)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 wrote an essay so there's more but not bothered to type it soz

Section D

1) 2004/2005?

2)the dotted lines were close together?

3) the bird thing sample too small only myb it is useful as there is an increase more breeding idk

Ocr gateway biology UNNOFICIAL MARKSCHEME

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