AQA GCSE Combined Science: Synergy — Paper 2 (Life and Environmental Sciences, Foundation Tier)

Total marks: 100 · Duration: 105 minutes · Tier: Foundation

Instructions to candidates

Answer all questions in the spaces provided.
You are expected to use a calculator where appropriate.
This paper assesses Life and Environmental Sciences: photosynthesis and respiration, coordination and control, and ecosystems and the environment.
The maximum mark for this paper is 100. The marks for each question are shown in brackets.

Paper

Section A — Multiple Choice (10 marks)

For each question, choose the one correct answer.

1. Which gas is used up during photosynthesis? (1 mark) A) Oxygen B) Carbon dioxide C) Nitrogen D) Hydrogen

2. Aerobic respiration releases energy using… (1 mark) A) carbon dioxide B) oxygen C) nitrogen D) lactic acid

3. Which controls blood glucose concentration? (1 mark) A) ADH B) Insulin C) Oestrogen D) Adrenaline

4. A reflex action is controlled by the… (1 mark) A) conscious brain B) nervous system without the conscious brain C) heart D) liver

5. Energy enters most ecosystems from the… (1 mark) A) soil B) Sun C) water D) air

6. Which organisms break down dead material? (1 mark) A) Producers B) Predators C) Decomposers D) Herbivores

7. Which gas, released by respiration and combustion, is a greenhouse gas? (1 mark) A) Oxygen B) Nitrogen C) Carbon dioxide D) Argon

8. Anaerobic respiration in human muscle produces… (1 mark) A) ethanol B) lactic acid C) oxygen D) glucose

9. Which is an abiotic factor in an ecosystem? (1 mark) A) Predators B) Temperature C) Competition D) Disease

10. Deforestation tends to… (1 mark) A) increase biodiversity B) decrease biodiversity C) reduce CO₂ D) have no effect

Section B — Structured Questions (90 marks)

11. Plants make food by photosynthesis. (14 marks) (a) Write the word equation for photosynthesis. (2 marks) (b) State three factors that affect the rate of photosynthesis. (3 marks) (c) A student measured oxygen bubbles from pondweed at different light intensities. Describe and explain the results expected. (4 marks) (d) Explain why a farmer might add carbon dioxide and heat to a greenhouse. (3 marks) (e) Give two uses of the glucose made by a plant. (2 marks)

12. Respiration releases energy. (13 marks) (a) Write the word equation for aerobic respiration. (2 marks) (b) State three uses of energy in living organisms. (3 marks) (c) Compare aerobic and anaerobic respiration in humans. (4 marks) (d) Define metabolism. (2 marks) (e) Explain what causes the "oxygen debt" after hard exercise. (2 marks)

13. The body coordinates responses. (14 marks) (a) Name the parts of the central nervous system. (2 marks) (b) Put the reflex arc in order: receptor, sensory neurone, effector, relay neurone, motor neurone. (2 marks) (c) Describe how a nerve impulse crosses a synapse. (3 marks) (d) Define homeostasis. (1 mark) (e) Describe how insulin lowers blood glucose after a meal. (3 marks) (f) State one difference between nervous and hormonal communication. (3 marks)

14. Organisms live in ecosystems. (14 marks) (a) Define the terms population and community. (2 marks) (b) Name two things animals compete for. (2 marks) (c) Describe how to use a quadrat to estimate the number of plants in a field. (4 marks) (d) Describe the carbon cycle, including how carbon enters and leaves living things. (4 marks) (e) Explain why decomposers are important. (2 marks)

15. Human activity affects the environment. (12 marks) (a) Name two greenhouse gases. (2 marks) (b) Describe how greenhouse gases cause global warming. (3 marks) (c) Give two possible effects of global warming on ecosystems. (2 marks) (d) Give two human activities that reduce biodiversity. (2 marks) (e) Describe two ways biodiversity can be protected. (2 marks) -- wait (e) Describe one way biodiversity can be protected. (1 mark)

16. Extended response. (9 marks) (a) Explain how the leaf is adapted for efficient photosynthesis. (3 marks) (b) A scientist wants to investigate how temperature affects the rate of respiration in yeast. Describe a method she could use and explain how she would make it a fair test. (6 marks)

17. This question is about photosynthesis, respiration and control. (14 marks) (a) Write the word equation for aerobic respiration. (2 marks) (b) Compare aerobic and anaerobic respiration in terms of oxygen, products and energy released. (2 marks) (c) Name the gas used up in photosynthesis. (1 mark) (d) State three factors that can limit the rate of photosynthesis. (3 marks) (e) Define homeostasis. (1 mark) (f) Describe how insulin lowers blood glucose after a meal. (3 marks) (g) Name the process that recycles carbon from dead organisms back to the air. (1 mark) (h) Name one greenhouse gas. (1 mark)

Mark Scheme

1. B 2. B 3. B 4. B 5. B 6. C 7. C 8. B 9. B 10. B [10]

11. (a) carbon dioxide + water → glucose + oxygen B1 B1 (b) light intensity, CO₂ concentration, temperature B1 B1 B1 (c) as light intensity increases, rate increases (1); levels off when another factor limits (1); more bubbles at higher intensity (1); valid data description (1) B1×4 (d) CO₂ and warmth increase the rate of photosynthesis (1+1); so faster growth/more yield (1) B1 B1 B1 (e) any two: respiration, stored as starch, making cellulose/proteins B1 B1 [14]

12. (a) glucose + oxygen → carbon dioxide + water B1 B1 (b) any three: movement, keeping warm, building molecules, active transport B1 B1 B1 (c) aerobic: uses oxygen, more energy, CO₂ + water (2); anaerobic: no oxygen, less energy, lactic acid (2) B1×4 (d) the sum of all reactions in a cell/body B1 B1 (e) lactic acid builds up (1); extra oxygen needed to break it down (1) B1 B1 [13]

13. (a) brain and spinal cord B1 B1 (b) receptor→sensory→relay→motor→effector B2 (B1 one error) (c) neurotransmitter released (1); diffuses across the gap (1); triggers impulse in next neurone (1) B1 B1 B1 (d) keeping a constant internal environment B1 (e) insulin from pancreas (1); glucose into cells (1); stored as glycogen (1) B1 B1 B1 (f) nervous: fast, short-lived, electrical; hormonal: slower, longer-lasting, chemical — any clear difference B1 B1 B1 [14]

14. (a) population = all organisms of one species in an area (1); community = all the populations together (1) B1 B1 (b) any two: food, water, mates, territory B1 B1 (c) place quadrat randomly (1); count organisms (1); repeat many times (1); mean × total area (1) B1×4 (d) CO₂ removed by photosynthesis (1); passed along food chains (1); returned by respiration (1); and decomposition/combustion (1) B1×4 (e) break down dead matter (1); recycle mineral ions/CO₂ for reuse (1) B1 B1 [14]

15. (a) any two: carbon dioxide, methane, water vapour B1 B1 (b) absorb heat radiated by Earth (1); re-radiate it (1); warming the atmosphere (1) B1 B1 B1 (c) any two: habitat loss, species migration/extinction, changing distributions B1 B1 (d) any two: deforestation, pollution, burning fossil fuels B1 B1 (e) any one: reserves, breeding programmes, reforestation B1 [12]

16. (a) large surface area; thin; many chloroplasts; stomata for gas exchange — any 3 B1 B1 B1 (b) levels, 6: method — yeast + glucose at different temperatures, measure CO₂ bubbles/gas in fixed time; fair test — same volume/concentration of glucose, same yeast, only change temperature; repeat for reliability. L3 (5–6) clear method + control; L2 (3–4); L1 (1–2). [9]

17. (a) glucose + oxygen → carbon dioxide + water B1 B1 (b) aerobic uses oxygen and releases more energy (1); anaerobic has no oxygen, releases less energy and makes lactic acid (1) B1 B1 (c) carbon dioxide B1 (d) light intensity, CO₂ concentration, temperature B1 B1 B1 (e) keeping a constant internal environment B1 (f) insulin (from the pancreas) is released (1); glucose moves into cells (1); stored as glycogen in the liver (1) B1 B1 B1 (g) decomposition / decay B1 (h) any one: carbon dioxide, methane, water vapour B1 [14]

AQA GCSE Combined Science (Synergy) — Paper 2 (Life and Environmental Sciences, Foundation Tier)