2 max
(c) 1. Water used for support / turgidity;
Accept: water used in (the cell’s) hydrolysis or condensation (reactions) for one mark. Allow a named example of these reactions
2. Water used in photosynthesis;
3. Water produced in respiration;
4. Apparatus not sealed / ‘leaks’;
2 max
(d) As number of leaves are reduced (no mark),
Accept: converse arguments
1. Less surface area / fewer stomata;
3. Less evaporation / transpiration;
4. Less cohesion / tension / pulling (force);
3
[8]
M11.(a) Prevents oxygen being taken up / entering / being absorbed;
Accept: any idea of no contact with oxygen.
Neutral: for anaerobic respiration / anaerobic conditions.
Neutral: prevents entry of air.
Reject: prevents entry of oxygen and another named gas.
1
(b) (i) 0.0155 / 0.016 = 2 marks;;
0.0775 / 0.077 / 0.078 / 0.08 = 1 mark
/ 0.62 = 1 mark
2
(ii) Glucose decreases / is a limiting factor / increase in ethanol / yeast / cells die / toxins build up;
Accept: glucose is used up.
1
(iii) 1. (Stays the) same / level / (relatively) constant;
2. Same volume / amount of oxygen uptake and carbon dioxide release;
Note: if m.p.1 is awarded m.p 2 can be obtained without referring to ‘same volume / amount’.
2
(c) 1. Oxygen is final / terminal (electron) acceptor / oxygen combines with electrons and protons;
2. Oxidative phosphorylation / electron transport chain provides (most) ATP / only glycolysis occurs without oxygen / no Krebs / no link reaction;
2
[8]
M12.(a) 1. To show the effect of the inhibitor / drug;
2. To show the effect of yoghurt (on its own does not affect blood
glucose);
2
(b) 1. Food is a factor affecting blood glucose / different foods contain
different amounts of starch / glucose / sugar / carbohydrate;
Accept converse
2. To keep starch / fibre intake the same / similar;
Accept something in food which affects the inhibitor
2
(c) 1. Fewer E-S complexes formed;
2. (With inhibitor) less / no starch digested to maltose ;
Require knowledge that maltose comes from starch
3. (So) less / no glucose from maltose;
Require knowledge that glucose comes from maltose
Accept no glucose
4. (So) less absorption of glucose (from gut);
2 max
(d) Suitable reason; with explanation;
Paired responses – do not mix and match
Ignore references to correlation does not prove causation,
it could be due to other factors
Examples,
1. Need larger sample / only 30 mice / only 15 mice in each group;
Accept small sample size
2. Might not be representative / anomalies might have a bigger or smaller effect;
Accept mean not reliable
OR
3. Investigation only lasted 20 days;
Experiment was not long enough
4. Can’t see what longer term effects are;
OR
5. Fall in blood glucose is small / numbers from graph;
6. Mice with inhibitor still have a large rise in blood glucose / so don’t know if differences significant;
Accept differences are due to chance
OR
7. No stats / SDs / SEs;
8. So don’t know if differences significant;
OR
9. Blood glucose could continue to fall;
10. which could be harmful;
OR
11. No group without yoghurt;
12. So cannot compare to other groups;
2 max
[8]
M13.(a) 1. Equilibrium reached.
Accept equilibrate
2. Allow for expansion / pressure change in apparatus;
3. Allow respiration rate of seeds to stabilise.
Ignore seeds acclimatise
3
(b) 1. Optimum temperature / temperature for normal growth of seeds;
2. (Optimum temperature) for enzymes involved in respiration.
2
(c) 1. Oxygen taken up / used by seeds;
2. CO2 given out is absorbed by KOH (solution);
3. Volume / pressure (in B) decreases.
3
(d) 0.975 / 0.98.
If incorrect,
0.26 × 6 / or incorrect numbers divided by 1.6 for 1 mark
2
[10]
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