Year 9 is the awkward bridge year: still Key Stage 3 in school life, but already starting GCSE habits. This page gives free Year 9 Biology practice from GradeNinja's own bank - 58 auto-marked questions across 2 Year 9 topic sets.
The aim is not to cram GCSE papers early. It is to make the first GCSE topics feel normal: short retrieval practice, clear corrections, and enough repetition that classwork sticks before Year 10 gets busy.
Use these as ten-minute checks after a lesson or before homework. If you miss one, read the explanation, then come back tomorrow and answer it cold.
Year 9 questions are pulled from late Key Stage 3 and foundation GCSE bridge material. They should feel harder than Year 8, but they are not meant to be full Year 11 exam questions.
Answer first, then reveal. The useful bit is the retrieval attempt, not reading the answer. If a topic keeps going wrong, paste the homework or Google Classroom text into GradeNinja's Classroom import tool and turn it into a focused pack.
Real questions from GradeNinja's own bank, with the answer and the explanation the app gives. Tap to reveal.
Catalysts for chemical reactions
Enzymes are biological catalysts — they speed up chemical reactions in living organisms without being used up themselves.
Dominant
A dominant allele is always expressed in the phenotype whenever it is present, whether the individual is homozygous (two copies) or heterozygous (one copy). It masks the effect of a recessive allele.
Amylase
Salivary amylase is produced in the salivary glands and begins the digestion of starch in the mouth, breaking it down into maltose. Amylase is also produced by the pancreas and continues starch digestion in the small intestine.
All the organisms of different species living together in a habitat
A community is all the organisms of different species living together in a habitat. A single species group is a population.
Producer
Producers (usually green plants or algae) make their own food using sunlight via photosynthesis. They are always at the start of a food chain.
The mass of living material at each trophic level
A pyramid of biomass shows the total mass of living material (dry mass) at each trophic level. It is nearly always pyramid-shaped because energy is lost at each stage — typically only about 10% of energy passes from one level to the next (the rest is lost as heat, waste, movement).
25%
In a monohybrid cross of Aa x Aa, the offspring can be AA, Aa, or aa. The homozygous offspring (AA and aa) represent 25% of the total, specifically 1 out of 4 being AA and 1 out of 4 being aa. Remember the ratio of genotypes produced in this cross.
It denatures — the active site changes shape permanently
Above the optimum temperature, the enzyme denatures. The bonds holding its 3D shape break, so the active site changes shape and the substrate can no longer fit. This is irreversible. Below optimum temperature, enzymes still work but more slowly.
They increase surface area and have a good blood supply
Villi give a large surface area, thin walls and a good blood supply, so digested food molecules are absorbed quickly.
Lock and key model
The lock and key model describes how the substrate (the "key") fits precisely into the active site of the enzyme (the "lock"). Only the correctly shaped substrate fits, which is why enzymes are specific to one reaction. The induced fit model is a more advanced version but lock and key is the AQA GCSE model.
Cell membrane
The cell membrane controls movement into and out of the cell. The nucleus controls cell activities and contains DNA.
All the living organisms in an area and their non-living environment
An ecosystem consists of all living organisms in a specific area, along with their non-living environment, such as soil, water, and climate. This concept is fundamental in ecology, as it shows the interactions between biotic and abiotic components. Remember, ecosystems are about relationships in nature.
Ethanol and carbon dioxide
Yeast carries out anaerobic respiration (fermentation) producing ethanol (alcohol) and carbon dioxide. This is exploited in bread-making (CO2 causes rising) and brewing (ethanol production).
Carbon dioxide + water → glucose + oxygen
Photosynthesis: CO₂ + H₂O → C₆H₁₂O₆ + O₂. Plants absorb carbon dioxide from the air and water from the soil, then use light energy to make glucose and release oxygen as a by-product.
A bacterium ingested in contaminated food, such as undercooked poultry or eggs
Salmonella is a bacterium that can infect the gut, digestive system, and body of farm animals, spreading to humans through contaminated food.
Adenine–Thymine and Cytosine–Guanine
In DNA: adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). This complementary base pairing holds the two strands together.
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Start revising free →They are bridge questions: harder than early Key Stage 3, but not pitched as full Year 11 GCSE exam papers. The point is to prepare the habits and core knowledge early.
Yes. Use Classroom import in the app: paste the Google Classroom post, homework email or assignment brief and it turns the topics into practice questions and flashcards.
Short and often. Ten minutes after a lesson or a few times a week is more useful than one long session before a test.
Yes, signing up is free. GradeNinja has Year 9 bridge content plus the wider question bank across 28 subjects.