Question Marking Guidance Mark Comments
01.1 1. Equilibrium reached;
2. Allow for expansion/pressure change in apparatus;
3. Allow respiration rate of seeds to stabilise; 3 1. Accept equilibrate
3. Ignore seeds
...
Question Marking Guidance Mark Comments
01.1 1. Equilibrium reached;
2. Allow for expansion/pressure change in apparatus;
3. Allow respiration rate of seeds to stabilise; 3 1. Accept equilibrate
3. Ignore seeds acclimatise
01.2 1. Optimum temperature/temperature for normal growth of seeds;
2. (Optimum temperature) for enzymes involved in respiration; 2
01.3 1. Oxygen taken up/used by seeds;
2. CO2 given out is absorbed by KOH (solution);
3. Volume/pressure (in B) decreases; 3
01.4 0.975/0.98; 2 If incorrect,
0.26 × 6 / or incorrect numbers divided by
1.6 for 1 mark
Question Marking Guidance Mark Comments
02.1 1. Calcium ions diffuse into myofibrils from (sarcoplasmic) reticulum;
2. (Calcium ions) cause movement of tropomyosin (on actin);
3. (This movement causes) exposure of the binding sites on the actin;
4. Myosin heads attach to binding sites on actin;
5. Hydrolysis of ATP (on myosin heads) causes myosin heads to bend;
6. (Bending) pulling actin molecules;
7. Attachment of a new ATP molecule to each myosin head causes myosin heads to detach (from actin sites); 5 max
02.2 1. Releases relatively small amount of energy / little energy lost as heat;
2. Releases energy instantaneously;
3. Phosphorylates other compounds, making them more reactive;
4. Can be rapidly re-synthesised;
5. Is not lost from/does not leave cells; 2 max 1. Key concept is that little danger of thermal death of cells
2. Key concept is that energy is readily available
............................................................................continued...................................................................................................
[Show More]