IGCSE Biology Practice Test 17 – 60 Questions with Answers (Cambridge 0610)
Work through this mixed-topic test under timed conditions, then use your mistakes to target the topics that need another look.
Characteristics and classification of living organisms
Q1. Which life process allows organisms to detect and respond to changes in their surroundings?
- (A) Growth
- (B) Excretion in this context, when the other conditions are taken into account
- (C) Nutrition
- (D) Sensitivity
Show Answer
Answer: D – Sensitivity is the ability to detect stimuli and make appropriate responses to them.
Q2. Which kingdom contains organisms that are single-celled, have a nucleus, and may photosynthesise?
- (A) Protoctist
- (B) Fungus
- (C) Animal
- (D) Prokaryote in this context, when the other conditions are taken into account
Show Answer
Answer: A – Protoctists are mostly single-celled eukaryotes, including some photosynthetic forms such as Chlorella.
Q3. Which kingdom contains organisms with cells that have no true nucleus?
- (A) Fungi, whose cells have nuclei and cell walls of chitin
- (B) Prokaryotes
- (C) Plants
- (D) Protoctists
Show Answer
Answer: B – Prokaryotes, including bacteria, have no nucleus, so their DNA lies free in the cytoplasm.
Organisation of the organism
Q4. Which structure is found in plant cells but not in animal cells?
- (A) Mitochondrion
- (B) Ribosome
- (C) Chloroplast
- (D) Nucleus
Show Answer
Answer: C – Chloroplasts contain chlorophyll for photosynthesis and are present in plant cells but not animal cells.
Q5. Which tissue in a leaf is responsible for photosynthesis?
- (A) Epidermis in this context, when the other conditions are taken into account
- (B) Palisade mesophyll
- (C) Xylem
- (D) Cuticle
Show Answer
Answer: B – Palisade mesophyll cells are packed with chloroplasts near the upper surface where light is strongest.
Q6. Which organelle releases most of the energy in aerobic respiration?
- (A) Mitochondrion
- (B) Cell membrane in this context, when the other conditions are taken into account
- (C) Vacuole
- (D) Golgi body
Show Answer
Answer: A – Mitochondria are the sites where most energy is released during aerobic respiration.
Movement into and out of cells
Q7. Which substance moves into root hair cells mainly by active transport when soil levels are low?
- (A) Water
- (B) Oxygen
- (C) Mineral ions
- (D) Carbon dioxide
Show Answer
Answer: C – Mineral ions can be taken up against a concentration gradient by active transport, using energy.
Q8. A red blood cell placed in a concentrated salt solution will shrink. Why?
- (A) Salt enters the cell rapidly in this context, when the other conditions are taken into account
- (B) The cell wall contracts
- (C) Protein synthesis stops
- (D) Water leaves the cell by osmosis
Show Answer
Answer: D – Water moves out by osmosis towards the higher solute concentration, so the cell shrinks and crenates.
Q9. Which condition speeds up diffusion of a gas into a liquid?
- (A) A smaller concentration difference
- (B) A thicker barrier
- (C) A larger surface area
- (D) A lower temperature
Show Answer
Answer: C – A larger surface area gives more space for particles to cross, so diffusion proceeds faster.
Biological molecules
Q10. Which food test turns from blue to purple in the presence of protein?
- (A) Iodine test
- (B) Benedict’s test
- (C) Emulsion test
- (D) Biuret test
Show Answer
Answer: D – Biuret solution changes from blue to purple when protein is present.
Q11. Which food test is used to detect the presence of protein?
- (A) Benedict’s test, which gives a brick-red precipitate when heated with a reducing sugar
- (B) Biuret test
- (C) Iodine test
- (D) Emulsion test
Show Answer
Answer: B – Biuret solution turns from blue to purple when protein is present in a sample.
Q12. Which carbohydrate is the main storage carbohydrate in animals?
- (A) Glycogen
- (B) Cellulose
- (C) Sucrose
- (D) Starch
Show Answer
Answer: A – Glycogen is stored in the liver and muscles of animals and can be broken down to glucose when needed.
Enzymes
Q13. Which term describes the model where the substrate fits exactly into the enzyme?
- (A) Lock and key model
- (B) Induced fit model only
- (C) Fluid mosaic model
- (D) Collision model
Show Answer
Answer: A – In the lock and key model, the substrate shape matches the active site shape precisely.
Q14. What happens to enzyme activity as pH moves away from the optimum in either direction?
- (A) Activity stays the same
- (B) Activity increases steadily
- (C) The enzyme gains a new substrate
- (D) Activity decreases
Show Answer
Answer: D – Moving away from the optimum pH alters the active site shape, reducing the rate until the enzyme denatures.
Q15. Which enzyme breaks down proteins in the stomach?
- (A) Amylase
- (B) Lipase
- (C) Pepsin
- (D) Maltase
Show Answer
Answer: C – Pepsin works in the acidic conditions of the stomach to digest proteins into smaller peptides.
Plant nutrition
Q16. Which mineral ion is needed by plants to make chlorophyll?
- (A) Nitrate
- (B) Magnesium
- (C) Phosphate in this context, when the other conditions are taken into account
- (D) Potassium
Show Answer
Answer: B – Magnesium is a central component of the chlorophyll molecule, so deficiency causes yellowing leaves.
Q17. Which part of a leaf cell absorbs light energy for photosynthesis?
- (A) Nucleus
- (B) Chloroplast
- (C) Vacuole
- (D) Mitochondrion
Show Answer
Answer: B – Chloroplasts contain chlorophyll, which absorbs light energy to drive photosynthesis.
Q18. A plant kept in bright light but without carbon dioxide will show which result?
- (A) Rapid starch formation
- (B) Faster growth than normal
- (C) Little or no photosynthesis
- (D) Increased oxygen uptake only
Show Answer
Answer: C – Carbon dioxide is a raw material for photosynthesis, so without it the process almost stops.
Human nutrition
Q19. Which vitamin is needed for healthy vision and is found in liver and carrots?
- (A) Vitamin C
- (B) Vitamin D
- (C) Vitamin B12
- (D) Vitamin A
Show Answer
Answer: D – Vitamin A is needed for normal vision, and deficiency can cause night blindness.
Q20. Which process in the stomach helps chemical digestion?
- (A) Churning mixes food with acid and enzymes
- (B) Villi absorb digested food
- (C) Bile emulsifies large fat droplets in this context, when the other conditions are taken into account
- (D) Water is reabsorbed into blood
Show Answer
Answer: A – The stomach muscles churn food, mixing it with hydrochloric acid and pepsin for digestion.
Transport in plants
Q21. Which tissue transports sugars made in leaves to other parts of a plant?
- (A) Xylem
- (B) Epidermis
- (C) Cambium
- (D) Phloem
Show Answer
Answer: D – Phloem carries sucrose and amino acids in translocation from sources to sinks.
Q22. What is the role of the stomata in a leaf?
- (A) They absorb water and mineral ions from the soil through the roots of the plant
- (B) They make chlorophyll
- (C) They allow gas exchange and control water loss
- (D) They transport sugars to the roots
Show Answer
Answer: C – Stomata open to let carbon dioxide in and oxygen out, and close to reduce water loss.
Transport in animals
Q23. Why can arteries carry blood pumped from the heart without bursting?
- (A) Their walls are thick, muscular and elastic
- (B) Their walls are thin and only one cell thick
- (C) They contain valves along their whole length
- (D) They carry blood at low pressure only
Show Answer
Answer: A – Thick, muscular and elastic walls stretch and recoil, allowing arteries to withstand the pressure of blood pumped from the heart.
Q24. Why does the right ventricle have a thinner wall than the left ventricle?
- (A) It receives blood directly from the body through the vena cava at high pressure
- (B) It only pumps blood a short distance to the lungs
- (C) It carries oxygenated blood only
- (D) It filters out platelets
Show Answer
Answer: B – The right ventricle pumps blood only to the nearby lungs, so it needs less muscle than the left ventricle.
Diseases and immunity
Q25. Which disease is spread by a virus and affects the immune system?
- (A) HIV/AIDS
- (B) Cholera
- (C) Tuberculosis
- (D) Malaria
Show Answer
Answer: A – HIV is a virus that attacks immune cells, weakening the body’s ability to fight infections.
Q26. Which type of white blood cell produces antibodies?
- (A) Platelet
- (B) Lymphocyte
- (C) Red blood cell
- (D) Phagocyte only
Show Answer
Answer: B – Lymphocytes produce specific antibodies that bind to antigens on a particular pathogen.
Q27. Which method reduces the spread of cholera in a community?
- (A) Sharing untreated water
- (B) Storing food uncovered
- (C) Ignoring sewage disposal
- (D) Providing clean water and sewage treatment
Show Answer
Answer: D – Clean water supplies and proper sewage treatment break the transmission route of cholera bacteria.
Gas exchange in humans
Q28. What happens to the volume of the chest during exhalation?
- (A) It increases because the intercostal muscles contract and raise the ribcage upwards and outwards
- (B) It stays the same
- (C) It decreases as the diaphragm relaxes and moves upwards
- (D) It doubles
Show Answer
Answer: C – During exhalation the ribs fall and the diaphragm domes up, so chest volume falls and air is pushed out.
Q29. Which change occurs in the chest during exhalation?
- (A) Volume increases and pressure falls
- (B) Ribcage moves up and out
- (C) Volume decreases and air is forced out
- (D) Diaphragm flattens further
Show Answer
Answer: C – As muscles relax, chest volume falls, pressure rises above air pressure, and air flows out.
Q30. Why is the wall of a capillary only one cell thick?
- (A) To allow rapid diffusion of gases and nutrients
- (B) To withstand high blood pressure
- (C) To carry blood quickly to veins
- (D) To prevent exchange with tissues
Show Answer
Answer: A – A one-cell-thick wall gives a short diffusion distance for oxygen, carbon dioxide and nutrients.
Respiration
Q31. Which product is made by anaerobic respiration in yeast?
- (A) Lactic acid only
- (B) Ethanol and carbon dioxide
- (C) Water and oxygen
- (D) Glucose and ethanol
Show Answer
Answer: B – Yeast respires anaerobically to produce ethanol and carbon dioxide, used in brewing and baking.
Q32. What is meant by oxygen debt after vigorous exercise?
- (A) Oxygen stored in the lungs
- (B) Oxygen lost in sweat
- (C) Extra carbon dioxide in blood
- (D) Extra oxygen needed to break down lactic acid
Show Answer
Answer: D – After exercise, extra oxygen is needed to oxidise lactic acid built up during anaerobic respiration.
Q33. Which experiment shows that germinating seeds respire and release carbon dioxide?
- (A) Seeds in light produce oxygen
- (B) Hydrogencarbonate indicator turns yellow in their presence
- (C) Seeds absorb water only
- (D) Limewater stays clear
Show Answer
Answer: B – Carbon dioxide from respiring seeds turns hydrogencarbonate indicator from red to yellow.
Excretion in humans
Q34. Which process in the kidney forms the filtrate from blood plasma?
- (A) Ultrafiltration at the glomerulus
- (B) Selective reabsorption in the liver
- (C) Secretion into the bladder
- (D) Diffusion across the ureter wall
Show Answer
Answer: A – High pressure in the glomerulus forces small molecules out of the blood to form filtrate.
Q35. Which substance is normally absent from the urine of a healthy person?
- (A) Urea
- (B) Water
- (C) Salts
- (D) Glucose
Show Answer
Answer: D – Glucose is fully reabsorbed in the kidney tubule, so it does not normally appear in urine.
Q36. Which hormone helps the kidney conserve water when the body is dehydrated?
- (A) Insulin
- (B) Adrenaline
- (C) ADH
- (D) Testosterone
Show Answer
Answer: C – ADH increases water reabsorption in the kidney, producing smaller volumes of concentrated urine.
Coordination and response
Q37. Which part of the eye changes shape to focus on near objects?
- (A) Cornea
- (B) Retina
- (C) Sclera
- (D) Lens
Show Answer
Answer: D – Ciliary muscles contract for near vision, allowing the lens to become thicker and more curved.
Q38. Which response helps a plant shoot grow towards light?
- (A) Geotropism
- (B) Thigmotropism
- (C) Phototropism
- (D) Chemotropism
Show Answer
Answer: C – Phototropism is growth towards light, controlled by auxin moving to the shaded side of the shoot.
Q39. Which hormone prepares the body for a rapid response to danger?
- (A) Insulin
- (B) Adrenaline
- (C) ADH
- (D) Oestrogen
Show Answer
Answer: B – Adrenaline increases heart rate and blood glucose, preparing muscles for fight or flight.
Drugs
Q40. Which drug is a stimulant found in tobacco smoke that affects the brain?
- (A) Nicotine
- (B) Alcohol
- (C) Heroin
- (D) Penicillin
Show Answer
Answer: A – Nicotine is addictive and acts on the nervous system, while tar and carbon monoxide damage the lungs and blood.
Q41. Which statement describes drug misuse?
- (A) Taking a prescribed dose exactly as directed
- (B) Using a drug in a way that harms health or social life
- (C) Storing medicines in a locked cupboard
- (D) Completing a full course of antibiotics
Show Answer
Answer: B – Misuse means using drugs excessively or for non-medical purposes in ways that damage health.
Q42. Which risk is linked to smoking during pregnancy?
- (A) Stronger bones in the baby
- (B) Faster lung development
- (C) Improved birth weight
- (D) Low birth weight and higher risk of miscarriage
Show Answer
Answer: D – Carbon monoxide and nicotine reduce oxygen supply to the fetus, increasing the risk of low birth weight.
Reproduction
Q43. Which structure produces pollen in a flower?
- (A) Anther
- (B) Ovary
- (C) Sepal
- (D) Stigma in this context, when the other conditions are taken into account
Show Answer
Answer: A – The anther at the top of the filament produces pollen grains containing male gametes.
Q44. Which event in the menstrual cycle usually occurs around day 14?
- (A) Menstruation begins
- (B) The uterus lining is shed fully
- (C) Ovulation
- (D) Fertilisation always occurs
Show Answer
Answer: C – Ovulation, the release of an egg from an ovary, typically occurs midway through the cycle.
Q45. Which method of contraception also reduces transmission of sexually transmitted infections?
- (A) The pill
- (B) An intrauterine device
- (C) A condom
- (D) A diaphragm alone
Show Answer
Answer: C – A condom acts as a barrier that prevents sperm and many pathogens from passing between partners.
Inheritance
Q46. Which term describes the observable features of an organism?
- (A) Phenotype
- (B) Genotype
- (C) Allele
- (D) Chromosome
Show Answer
Answer: A – The phenotype is the set of observable characteristics, resulting from genotype and environment.
Q47. In a monohybrid cross between two heterozygous parents, what ratio of dominant to recessive phenotypes is expected?
- (A) 1 to 1 in this context, when the other conditions are taken into account
- (B) 2 to 1
- (C) 4 to 0
- (D) 3 to 1
Show Answer
Answer: D – The cross gives genotypes 1 AA, 2 Aa and 1 aa, so three offspring show the dominant trait for every one recessive.
Q48. Which sex chromosome combination is found in a human female?
- (A) XY in this context, when the other conditions are taken into account
- (B) XX
- (C) YY
- (D) XO
Show Answer
Answer: B – Females have two X chromosomes, while males have one X and one Y chromosome.
Variation and selection
Q49. Which of these is an example of discontinuous variation?
- (A) Height, which varies gradually across a full range of values in a population
- (B) Body mass
- (C) Skin colour
- (D) Blood group
Show Answer
Answer: D – Blood group falls into distinct categories determined by genes, with no intermediate values.
Q50. Which factor is a source of variation in sexual reproduction?
- (A) Identical gametes
- (B) Random fusion of gametes
- (C) Mitosis only
- (D) Single parent cloning
Show Answer
Answer: B – Random fusion of different gametes at fertilisation produces new gene combinations in offspring.
Q51. Which statement about selective breeding is correct?
- (A) It increases genetic diversity
- (B) It relies on random mutations only
- (C) Humans choose parents with desired traits over many generations
- (D) It always produces disease resistance
Show Answer
Answer: C – Selective breeding involves choosing organisms with useful traits as parents across generations.
Organisms and their environment
Q52. Which term describes all the populations of different species living in one area?
- (A) Community
- (B) Ecosystem in this context, when the other conditions are taken into account
- (C) Habitat
- (D) Niche
Show Answer
Answer: A – A community is all the interacting populations in an area, while an ecosystem also includes non-living factors.
Q53. In a food web, what is a herbivore?
- (A) An animal that feeds only on producers, such as grass and leaves
- (B) An animal that feeds on other animals at the top of a food chain in a woodland habitat
- (C) A fox eating rabbits
- (D) A tree capturing light
Show Answer
Answer: A – Herbivores are primary consumers that feed on plants and other producers.
Q54. Why are food chains usually short?
- (A) Producers are scarce
- (B) Consumers eat too little
- (C) Energy is lost at each trophic level
- (D) Decomposers remove all energy
Show Answer
Answer: C – Only a small proportion of energy passes to the next level, so there is too little to support many levels.
Human influences on ecosystems
Q55. Which gas contributes most to the enhanced greenhouse effect from human activity?
- (A) Oxygen
- (B) Carbon dioxide
- (C) Nitrogen
- (D) Argon
Show Answer
Answer: B – Carbon dioxide from fossil fuels and deforestation traps outgoing heat and warms the climate.
Q56. Which effect of deforestation reduces biodiversity?
- (A) More soil nutrients
- (B) Increased rainfall locally
- (C) Larger forest area
- (D) Loss of habitats and food sources
Show Answer
Answer: D – Clearing forests destroys habitats, so many species lose shelter and food and may die out locally.
Q57. Which practice helps conserve fish stocks?
- (A) Catching juveniles before they can breed
- (B) Using fine nets in breeding grounds
- (C) Setting quotas and closed seasons
- (D) Fishing without any limits
Show Answer
Answer: C – Quotas and closed seasons allow fish to breed and stocks to recover, supporting sustainable fishing.
Biotechnology and genetic modification
Q58. Which product is made by anaerobic respiration in a fermenter using yeast?
- (A) Insulin
- (B) Ethanol for biofuel
- (C) Penicillin directly in this context, when the other conditions are taken into account
- (D) Cheese enzymes
Show Answer
Answer: B – Yeast fermenting sugars produces ethanol, which can be used as a biofuel.
Q59. Which benefit is claimed for genetically modified crops that resist insects?
- (A) Reduced need for insecticide spraying
- (B) Higher water pollution
- (C) Lower crop yields always
- (D) More land clearance needed
Show Answer
Answer: A – Insect-resistant crops suffer less pest damage, so farmers may need fewer insecticide applications.
Q60. Which concern is raised about genetically modified organisms?
- (A) They cannot be grown outdoors
- (B) They always cause allergies
- (C) They are identical to wild types
- (D) Modified genes could spread to wild relatives
Show Answer
Answer: D – A concern is that pollen from modified crops could transfer modified genes into wild populations.
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