Eduqas A Level Biology
Eduqas A Level Biology Component 3: Requirements for Life Exam Questions
Free Eduqas A Level Biology exam questions for Component 3: Requirements for Life, with a mark scheme for every pack. Covers gas exchange, transport in animals and plants, nutrition, the kidney and homeostasis, the nervous system and the optional topic.
Component 3: Requirements for Life exam questions
8 question packs of real past exam questions, each with its mark scheme. Do not stop after a few: answer as many as you can without notes, then mark every answer with the mark scheme. The more questions you do, the more quickly you will spot how examiners ask about each idea.
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About Eduqas A Level Biology Component 3: Requirements for Life
Component 3 of Eduqas A Level Biology, Requirements for Life, covers how organisms exchange gases, transport substances, obtain nutrients, control their internal environment and coordinate responses. It includes the kidney and osmoregulation, the nervous system, and one option chosen by your centre: Immunology and Disease, Human Musculoskeletal Anatomy, or Neurobiology and Behaviour. Much of the gas exchange, transport and nutrition content links to AS, while the kidney and nerves are new. Examiners test structure and function links, oxygen dissociation curves, the action potential, nephron processes and the option content, often with data or diagrams to interpret.
What you need to know
- 3.1 Gas exchange surfaces in single-celled organisms, flatworms, earthworms, fish (counter-current flow in bony fish), insects (tracheal system), mammals (alveoli and ventilation) and leaves (stomata and spongy mesophyll).
- 3.2 Open and closed circulation, the cardiac cycle and its control by the SAN, AVN and Purkinje fibres, haemoglobin and the Bohr effect, tissue fluid formation, and transpiration and translocation in plants.
- 3.3 Holozoic nutrition in the human gut, digestion and absorption in the ileum, adaptations of herbivore and carnivore dentition and the ruminant gut, and parasitic nutrition.
- 3.4 Ultrafiltration in the glomerulus, selective reabsorption in the proximal convoluted tubule, the loop of Henle as a countercurrent multiplier, and ADH acting on the collecting duct via negative feedback.
- 3.5 Structure of neurones, the resting potential of about -70 mV, depolarisation and repolarisation through voltage-gated sodium and potassium channels, saltatory conduction, synaptic transmission and the effect of drugs.
- Options Your centre studies one option: Immunology and Disease (pathogens, immune responses, vaccination, antibiotics), Human Musculoskeletal Anatomy (bones, joints, sliding filament theory), or Neurobiology and Behaviour (brain regions, learning and behaviour).
Common mistakes in Component 3: Requirements for Life
- Saying the loop of Henle reabsorbs water in the ascending limb. The ascending limb is impermeable to water and actively pumps out sodium and chloride ions; water leaves the descending limb by osmosis.
- Describing ADH as making the collecting duct walls permeable to salt. ADH causes aquaporins to be inserted into the membranes, increasing permeability to water.
- Explaining the Bohr effect as lower oxygen causing unloading. It is higher carbon dioxide concentration that shifts the curve right, lowering haemoglobin's affinity for oxygen.
- Saying an action potential is bigger if the stimulus is bigger. Action potentials are all or nothing; a stronger stimulus increases the frequency of impulses.
- Calling counter-current flow in fish parallel flow. Blood and water flow in opposite directions so a diffusion gradient is maintained along the whole lamella.
Try three Component 3: Requirements for Life exam-style questions
1. Explain how an action potential is generated after a neurone is stimulated. (4 marks)
Show the mark scheme answer
Stimulus opens voltage-gated sodium channels; sodium ions diffuse into the axon; membrane depolarises; if threshold is reached more sodium channels open (positive feedback); potential reaches about +40 mV; sodium channels close and potassium channels open, causing repolarisation.
2. A person's heart rate is 72 beats per minute and stroke volume is 70 cm3. Calculate cardiac output in dm3 per minute. (2 marks)
Show the mark scheme answer
72 x 70 = 5 040 cm3 per minute; = 5.04 dm3 per minute.
3. Explain how the structure of the glomerulus and Bowman's capsule is adapted for ultrafiltration. (3 marks)
Show the mark scheme answer
Afferent arteriole wider than efferent arteriole, creating high hydrostatic pressure; fenestrated capillary endothelium and basement membrane act as a filter; podocytes leave gaps for filtrate to pass; large proteins and cells are retained.
Component 3: Requirements for Life FAQs
What does Eduqas A Level Biology Component 3: Requirements for Life cover?
Gas exchange, transport, nutrition, homeostasis and the kidney, the nervous system, and one option out of Immunology and Disease, Human Musculoskeletal Anatomy, or Neurobiology and Behaviour.
Do I answer questions on all three options?
No. You answer the section on the one option your centre has taught, so check with your teacher which it is.
How should I revise the kidney for Requirements for Life?
Draw and label a nephron from memory, then annotate each region with what happens there and why, including water potential changes in the loop of Henle and the role of ADH.
