Eduqas A-Level Biology (A400)
A-Level Biology
Answer sheet
Requirements for life
Separate mark scheme — do not issue with the student worksheet
Time guide: — · Questions: 32 · Total marks: 104
Written in Eduqas A-Level style. Answer in continuous prose where the marks require explanation.
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
1. State what is meant by ATP.
[1 mark]
- adenine, ribose, three phosphates
2. State what is meant by glycolysis.
[1 mark]
- glucose to 2 pyruvate in cytoplasm
3. State what is meant by the link reaction.
4. State what is meant by the Krebs cycle.
[1 mark]
- oxidises acetate, produces reduced coenzymes and ATP
5. State what is meant by oxidative phosphorylation.
[1 mark]
- electrons down the ETC, chemiosmosis
6. State what is meant by photosynthesis light-dependent reaction.
[1 mark]
- thylakoid, photolysis, ATP and reduced NADP
7. State what is meant by the Calvin cycle.
[1 mark]
- stroma, RuBP + CO₂ → GP → TP
8. State what is meant by a limiting factor of photosynthesis.
[1 mark]
- light, CO₂ or temperature
9. State what is meant by a biomass transfer.
[1 mark]
- energy lost as heat, waste, not eaten
10. State what is meant by net primary production.
11. Jac is asked about ATP in a Eduqas Biology paper.
(a) [2 marks]
- immediate energy currency
(b) [3 marks]
- hydrolysis is catalysed by ATP hydrolase
12. Jac is asked about glycolysis in a Eduqas Biology paper.
13. Jac is asked about the link reaction in a Eduqas Biology paper.
14. Jac is asked about the Krebs cycle in a Eduqas Biology paper.
15. Jac is asked about oxidative phosphorylation in a Eduqas Biology paper.
(a) [2 marks]
- inner mitochondrial membrane
16. Jac is asked about photosynthesis light-dependent reaction in a Eduqas Biology paper.
17. NPP if GPP=80 and R=30 (arbitrary units)
18. Efficiency 12 000 kJ to 1 200 kJ
19. RQ of C₆H₁₂O₆: CO₂/O₂
20. 2 pyruvate from 1 glucose. How many CO₂ in two link reactions?
21. A plant fixes 6 CO₂. How many turns of Calvin cycle?
22. ATP from substrate-level phosphorylation per glucose in glycolysis
23. Jac carries out a Eduqas-style required practical linked to energy transfers. This is a typical Eduqas required-practical style question.
(a) [2 marks]
- Independent: the independent variable for this topic
- Dependent: the measured outcome
(b) [2 marks]
- keep all other variables constant
- so the test is fair / only one variable is changed
(c) [2 marks]
- repeat and calculate a mean / use a tighter method
24. Jac carries out collecting valid data for energy transfers. This is a typical Eduqas required-practical style question.
(a) [2 marks]
- Independent: a chosen factor
- Dependent: a quantitative measurement
(b) [2 marks]
- calibrated instrument
- so the test is fair / only one variable is changed
(c) [2 marks]
- systematic error from zero error
25. Jac carries out drawing a graph for energy transfers. This is a typical Eduqas required-practical style question.
(a) [2 marks]
- Independent: x-variable
- Dependent: y-variable
(b) [2 marks]
- same scale / same apparatus
- so the test is fair / only one variable is changed
(c) [2 marks]
- not drawing a line of best fit through the trend
26. Jac carries out evaluating a method about energy transfers. This is a typical Eduqas required-practical style question.
(a) [2 marks]
- Independent: method change
- Dependent: precision / accuracy
(b) [2 marks]
- same sample size
- so the test is fair / only one variable is changed
27. Compare ATP with glycolysis.
[4 marks]
- adenine, ribose, three phosphates
- glucose to 2 pyruvate in cytoplasm
- give one linked difference
28. Compare glycolysis with the link reaction.
[4 marks]
- glucose to 2 pyruvate in cytoplasm
- pyruvate to acetyl CoA
- give one linked difference
29. Compare the link reaction with the Krebs cycle.
[4 marks]
- pyruvate to acetyl CoA
- oxidises acetate, produces reduced coenzymes and ATP
- give one linked difference
30. Compare the Krebs cycle with oxidative phosphorylation.
[4 marks]
- oxidises acetate, produces reduced coenzymes and ATP
- electrons down the ETC, chemiosmosis
- give one linked difference
31. Apply your knowledge of the Calvin cycle to this situation: needs ATP and reduced NADP
[3 marks]
- needs ATP and reduced NADP
32. Apply your knowledge of a limiting factor of photosynthesis to this situation: shown by plateaus on graphs
[3 marks]
- shown by plateaus on graphs