Eduqas A Level Biology
Eduqas A Level Biology AS Component 2: Biodiversity and Physiology of Body Systems Exam Questions
Free Eduqas A Level Biology exam questions for AS Component 2: Biodiversity and Physiology of Body Systems, with a mark scheme for every pack. Covers classification, biodiversity and adaptation, gas exchange in animals and plants, circulation, transport in plants and nutrition.
AS Component 2: Biodiversity and Physiology of Body Systems exam questions
4 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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A-Level Biology Flashcards for 2027 Onwards
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Then test yourself with the questions on this page.
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About Eduqas A Level Biology AS Component 2: Biodiversity and Physiology of Body Systems
AS Component 2 of Eduqas AS Biology, Biodiversity and Physiology of Body Systems, looks at how organisms are classified and how they are adapted to exchange gases, transport materials and obtain nutrients. It compares a wide range of organisms, from amoeba and flatworms to fish, insects, mammals and flowering plants. It links back to membranes and diffusion from AS Component 1 and forward to the A Level Requirements for Life component. Examiners favour comparative questions, oxygen dissociation curves, cardiac cycle pressure graphs, potometer data, and describing digestion and absorption in the human gut.
What you need to know
- 2.1 Classification into three domains and five kingdoms, the hierarchy of taxa, the binomial system, the biological species concept, and evidence from DNA and protein comparisons. Natural selection and adaptation explain biodiversity.
- 2.2 Surface area to volume ratio and Fick's law. Gas exchange in amoeba, flatworm, earthworm, bony and cartilaginous fish, insects, humans (ventilation and alveoli) and leaves, including stomatal opening.
- 2.3 Open and closed, single and double circulatory systems; heart structure and the cardiac cycle; blood vessels; haemoglobin, the oxygen dissociation curve and Bohr effect; tissue fluid; xylem, transpiration, the cohesion-tension theory and translocation in phloem.
- 2.4 Autotrophic and heterotrophic nutrition; the human digestive system, enzymes and absorption in the ileum; adaptations of herbivores and carnivores; parasitic nutrition, for example tapeworms.
Common mistakes in AS Component 2: Biodiversity and Physiology of Body Systems
- Explaining that larger organisms have a larger surface area to volume ratio. As size increases, the ratio decreases, so specialised exchange surfaces and transport systems are needed.
- Saying the semilunar valves close when the ventricles contract. They open when ventricular pressure exceeds arterial pressure and close when ventricular pressure falls below it.
- Describing transpiration as water being pumped up the xylem. Water evaporation from leaves creates tension, and cohesion between water molecules pulls a continuous column up passively.
- Saying fetal haemoglobin has lower affinity for oxygen. It has a higher affinity, so its curve lies to the left of adult haemoglobin and it can load oxygen at the placenta.
- Forgetting that a potometer measures water uptake, not water loss. Most water taken up is lost by transpiration, but some is used in photosynthesis and to keep cells turgid.
Try three AS Component 2: Biodiversity and Physiology of Body Systems exam-style questions
1. Explain why bony fish need gills and how counter-current flow increases the efficiency of gas exchange. (4 marks)
Show the mark scheme answer
Fish have a small surface area to volume ratio and a waterproof, scaly surface; gills provide a large surface area of lamellae; blood and water flow in opposite directions; a concentration gradient is maintained across the whole length of the lamella; so more oxygen diffuses into the blood.
2. A bubble in a potometer capillary of radius 0.5 mm moved 30 mm in 5 minutes. Calculate the rate of water uptake in mm3 per minute. (3 marks)
Show the mark scheme answer
Volume = pi r^2 l = 3.14 x 0.5^2 x 30; = 23.6 mm3; rate = 23.6 / 5 = 4.7 mm3 per minute.
3. Describe how the ileum is adapted for absorption. (3 marks)
Show the mark scheme answer
Villi and microvilli give a large surface area; thin epithelium one cell thick gives a short diffusion distance; rich capillary network maintains a concentration gradient; many mitochondria for active transport; lacteals absorb fats.
AS Component 2: Biodiversity and Physiology of Body Systems FAQs
What does Eduqas AS Biology Component 2: Biodiversity and Physiology of Body Systems cover?
Biodiversity and classification, adaptations for gas exchange, adaptations for transport in animals and plants, and adaptations for nutrition.
How does this component link to A Level?
The same gas exchange, transport and nutrition content is assessed again in the A Level Requirements for Life component, so learn it thoroughly at AS.
What diagrams should I be able to draw for this component?
Practise the heart, a gill filament, the human gas exchange system, a transverse section of a leaf, xylem and phloem, and the oxygen dissociation curve showing the Bohr shift.
