Edexcel A-Level Biology A (Salters-Nuffield) sample questions and answers (9BN0)
Guide overview All 8 topics Sample questions Papers and weighting Look inside Questions and answers
40 sample questions and answers
Taken from every topic of Edexcel A-Level Biology A (Salters-Nuffield), specification 9BN0. The full guide has 1,892.
Paper 1, Paper 2, Paper 3
Lifestyle, Health and Risk
200 questions in the guide, across 13 subtopics. More from this topic
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Water and the carbohydrates
What is a disaccharide?
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A carbohydrate formed from two monosaccharide units joined together. -
Condensation, hydrolysis and glycosidic bonds
Which monosaccharides combine to form maltose?
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Two glucose molecules. -
The cardiac cycle and the structure of the heart
Describe what occurs during ventricular systole.
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The ventricles contract, closing the atrioventricular valves and forcing blood out through the semilunar valves into the arteries. -
Arteries, veins and capillaries
What type of tissue forms the capillary wall?
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A single layer of endothelium. -
The blood clotting cascade
What reaction does thrombin catalyse?
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Thrombin catalyses the conversion of soluble fibrinogen into insoluble fibrin.
Paper 1, Paper 2, Paper 3
Genes and Health
259 questions in the guide, across 19 subtopics. More from this topic
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Gas exchange surfaces and Fick's Law
State Fick's Law in words.
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The rate of diffusion is proportional to the surface area multiplied by the concentration difference, divided by the thickness of the exchange surface. -
Osmosis, diffusion and active transport
What types of proteins are involved in facilitated diffusion?
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Carrier proteins and channel proteins. -
The structure of DNA and RNA
Which pyrimidine base is found in both DNA and RNA?
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Cytosine. -
Translation and the genetic code
Define a codon.
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A sequence of three bases on mRNA that codes for a specific amino acid or a stop signal. -
Globular and fibrous proteins: haemoglobin and collagen
What are the two types of polypeptide chains in haemoglobin?
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Two alpha chains and two beta chains.
Paper 1, Paper 2, Paper 3
Voice of the Genome
194 questions in the guide, across 16 subtopics. More from this topic
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Prokaryotic cells
What is the function of the capsule found in some prokaryotic cells?
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It acts as a protective layer outside the cell wall. -
Identifying organelles in an electron micrograph
Describe the appearance of rough endoplasmic reticulum in an EM image.
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Flattened membrane sacs with dark dots (ribosomes) on the surface. -
Microscopy: the graticule, magnification and standard form
Convert 0.0045 into standard form.
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4.5 × 10⁻³ -
Core practical: the root tip squash
Why is the root tip tissue macerated or softened during preparation of a squash?
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To break down cell walls and separate cells, making them easier to spread into a single layer. -
The structure of sperm and egg cells
Why do sperm cells have numerous mitochondria in the midpiece?
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To provide ATP for the movement of the tail/flagellum.
Paper 1, Paper 2, Paper 3
Biodiversity and Natural Resources
287 questions in the guide, across 20 subtopics. More from this topic
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Biodiversity, species richness and the index of diversity
State the formula for calculating the heterozygosity index (H).
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H = number of heterozygotes ÷ total number of individuals in the population. -
Natural selection and evolution
What is evolution?
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Evolution is the cumulative change in the heritable characteristics of a population over successive generations. -
Classification
Which domain contains prokaryotes that often live in extreme environments and lack peptidoglycan in their cell walls?
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Archaea. -
The vacuole, plasmodesmata, pits and middle lamella
What is the desmotubule?
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A central strand of endoplasmic reticulum that runs through the plasmodesma. -
Lignin, xylem vessels and sclerenchyma fibres
Why is the pattern of lignin deposition in xylem vessels advantageous?
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It provides support while allowing some flexibility and lateral water movement.
Paper 1, Paper 3
On the Wild Side
319 questions in the guide, across 21 subtopics. More from this topic
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Photosynthesis: the light-dependent reactions
What would happen to GP levels in a chloroplast if light were suddenly removed?
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GP levels would increase because GP would continue to be formed by carbon fixation but could not be reduced to GALP without ATP and reduced NADP from the light-dependent reactions. -
Chloroplast structure and the products of photosynthesis
What type of molecule essential for storing genetic information can be synthesised using products of photosynthesis?
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Nucleic acids (DNA and RNA). -
Temperature, enzymes and Q10
How does temperature affect plants?
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Temperature influences the rate of photosynthesis and respiration, germination, flowering time, and growth rate through its effects on enzyme activity. -
Succession
What is a plagioclimax?
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A stable community prevented from reaching the climatic climax by human activity, such as grazing, mowing or burning. -
Evidence for climate change
How can dendrochronology records be extended beyond the age of a single tree?
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Ring patterns can be matched across different samples to extend records further back in time.
Paper 1, Paper 3
Immunity, Infection and Forensics
180 questions in the guide, across 15 subtopics. More from this topic
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Decomposition, succession and forensic entomology
Describe the advanced decay stage of decomposition.
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Most soft tissue has been removed; decomposition slows significantly and remaining tissue dries out. -
Body cooling and rigor mortis
When does rigor mortis reach maximum stiffness?
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Approximately 12–24 hours after death. -
Gel electrophoresis
Explain why shorter DNA fragments travel further through the gel than longer fragments.
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Shorter fragments move faster and further because they can pass more easily through the pores in the gel matrix. -
The structure of bacteria and viruses
Compare the typical size of bacteria and viruses.
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Bacteria are typically 1–5 μm in diameter, whereas viruses are much smaller at 20–300 nm. -
The body's barriers, and modelling bacterial growth
What antimicrobial substances can gut flora produce to protect against infection?
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Gut flora can produce antimicrobial substances such as bacteriocins and organic acids that inhibit or kill pathogenic micro-organisms.
Paper 2, Paper 3
Run for Your Life
213 questions in the guide, across 15 subtopics. More from this topic
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Muscles and Movement
Why do muscles need to work in pairs to produce movement at a joint?
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Because muscles can only generate force by contracting (pulling) and cannot push, so a second muscle is needed to produce movement in the opposite direction -
The myofibril and the sarcomere
During muscle contraction, what happens to the width of the I band?
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It gets shorter (narrower) -
Slow-twitch and fast-twitch muscle fibres
Which form of respiration do fast-twitch fibres mainly rely on?
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Anaerobic respiration (glycolysis) -
Glycolysis and the link reaction
Why would the fluid in a respirometer barely move if the soda lime were left out and the organisms were respiring glucose aerobically?
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Aerobic respiration of glucose releases the same volume of carbon dioxide as the volume of oxygen taken up, so the gas volume in the tube would stay almost the same. -
The conduction system: SAN, AVN and Purkyne fibres
After the SAN generates an impulse, where does it spread to next?
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The impulse spreads across the atria (atrial muscle).
Paper 2, Paper 3
Grey Matter
240 questions in the guide, across 17 subtopics. More from this topic
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The structure of neurones and myelination
What structural features of relay neurones allow them to integrate signals from multiple sources?
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They have short axons and numerous dendrites. -
The structure of a synapse and calcium entry
What is the synaptic cleft?
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The narrow gap between the presynaptic and postsynaptic membranes. -
Rod cells and the detection of light
What is the membrane potential of a rod cell in darkness, and why?
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Around −40mV; the influx of sodium ions keeps the rod cell depolarised. -
Phytochrome and the response to light
What happens to Pr when it absorbs red light?
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Pr is converted to Pfr -
Nervous against hormonal coordination
How long do the effects of nervous system responses typically last?
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Short-duration effects.
Edexcel A-Level Biology A (Salters-Nuffield) Active Recall Guide
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