IGCSE Biology Practice Test 20 – 60 Questions with Answers (Cambridge 0610)
Finish this series with a steady pass through all twenty-one topics, noting any question that still feels uncertain for final revision.
Characteristics and classification of living organisms
Q1. Which life process involves an increase in size and complexity over time?
- (A) Sensitivity
- (B) Excretion
- (C) Growth
- (D) Respiration
Show Answer
Answer: C – Growth is a permanent increase in size and dry mass as cells divide and enlarge.
Q2. Which kingdom includes multicellular organisms that photosynthesise and have cell walls of cellulose?
- (A) Animal
- (B) Fungus
- (C) Prokaryote
- (D) Plant
Show Answer
Answer: D – Plants are multicellular photosynthetic organisms with cellulose cell walls and chloroplasts.
Q3. Which arthropod group has three body parts, six legs and usually wings?
- (A) Crustaceans
- (B) Insects
- (C) Arachnids
- (D) Myriapods
Show Answer
Answer: B – Insects have a head, thorax and abdomen, six legs, and many have wings.
Organisation of the organism
Q4. Which structure controls the activities of a plant cell?
- (A) Nucleus
- (B) Vacuole
- (C) Cell wall
- (D) Chloroplast
Show Answer
Answer: A – The nucleus contains DNA instructions that control cell activities including growth and division.
Q5. Which tissue carries out photosynthesis in the stem of a young green plant?
- (A) Cortex cells with chloroplasts
- (B) Xylem
- (C) Phloem
- (D) Epidermis alone in this context, when the other conditions are taken into account
Show Answer
Answer: A – Green cortical cells in a young stem contain chloroplasts and can photosynthesise.
Q6. Which cell lacks a nucleus when mature and is adapted to transport sugars?
- (A) Guard cell
- (B) Palisade cell
- (C) Root hair cell in this context, when the other conditions are taken into account
- (D) Sieve tube element
Show Answer
Answer: D – Sieve tube elements lose their nuclei and are supported by companion cells in phloem.
Movement into and out of cells
Q7. Which term describes the movement of water across a partially permeable membrane?
- (A) Diffusion of solutes
- (B) Active transport
- (C) Osmosis
- (D) Translocation
Show Answer
Answer: C – Osmosis is the diffusion of water from higher to lower water potential across a partially permeable membrane.
Q8. Which change would increase the rate of active transport into a cell?
- (A) Lowering the temperature sharply
- (B) Increasing the supply of energy from respiration
- (C) Removing all carrier proteins
- (D) Reducing the number of mitochondria in this context, when the other conditions are taken into account
Show Answer
Answer: B – Active transport needs energy, so a better energy supply from respiration supports a faster rate.
Q9. A cell with a high solute concentration is placed in pure water. What is the net movement of water?
- (A) Out of the cell only
- (B) Into the cell
- (C) Equal in both directions at first
- (D) No movement at all
Show Answer
Answer: B – Water moves by osmosis towards the higher solute concentration inside the cell.
Biological molecules
Q10. Which test result shows that a sample contains reducing sugar?
- (A) Iodine stays brown
- (B) Biuret stays blue
- (C) Benedict’s solution turns brick-red on heating
- (D) Ethanol test stays clear in this context, when the other conditions are taken into account
Show Answer
Answer: C – A brick-red precipitate with Benedict’s solution on heating indicates a reducing sugar.
Q11. Which polymer is made from amino acids?
- (A) Starch
- (B) Cellulose
- (C) Glycogen
- (D) Protein
Show Answer
Answer: D – Amino acids join in long chains to form proteins, which fold into specific shapes.
Q12. Which substance is broken down to release energy in respiration?
- (A) Glucose
- (B) Cellulose
- (C) Chlorophyll
- (D) Haemoglobin
Show Answer
Answer: A – Glucose is the main respiratory substrate broken down to release energy.
Enzymes
Q13. Which enzyme is produced by the pancreas to digest starch?
- (A) Pepsin
- (B) Lipase
- (C) Trypsin in this context, when the other conditions are taken into account
- (D) Amylase
Show Answer
Answer: D – Pancreatic amylase continues starch digestion in the small intestine.
Q14. Which statement describes an enzyme-substrate complex?
- (A) Enzyme and product permanently joined in this context, when the other conditions are taken into account
- (B) Two enzymes joined together
- (C) Substrate bound to the active site before reaction
- (D) Enzyme changed into substrate
Show Answer
Answer: C – The substrate binds to the active site, forming a temporary complex while the reaction occurs.
Q15. Which condition is closest to the optimum for human amylase?
- (A) pH 7 and 37 degrees Celsius
- (B) pH 2 and 37 degrees Celsius
- (C) pH 12 and 20 degrees Celsius
- (D) pH 7 and 80 degrees Celsius
Show Answer
Answer: A – Human amylase works best near neutral pH at body temperature.
Plant nutrition
Q16. Which raw material for photosynthesis enters the leaf through stomata?
- (A) Water
- (B) Carbon dioxide
- (C) Oxygen
- (D) Glucose in this context, when the other conditions are taken into account
Show Answer
Answer: B – Carbon dioxide diffuses into the leaf through open stomata for use in photosynthesis.
Q17. Which product of photosynthesis is stored as starch in leaves?
- (A) Glucose
- (B) Oxygen
- (C) Water
- (D) Carbon dioxide
Show Answer
Answer: A – Glucose made in photosynthesis is converted to insoluble starch for storage in the leaf.
Q18. Which factor would increase the rate of photosynthesis in a well-watered plant in dim light?
- (A) Lowering carbon dioxide further
- (B) Increasing light intensity
- (C) Cooling the plant sharply
- (D) Removing chlorophyll
Show Answer
Answer: B – In dim light, light intensity limits the rate, so brighter light raises photosynthesis.
Human nutrition
Q19. Which enzyme digests proteins in the small intestine after pepsin has acted?
- (A) Amylase in this context, when the other conditions are taken into account
- (B) Lipase
- (C) Maltase
- (D) Trypsin
Show Answer
Answer: D – Trypsin from the pancreas continues protein digestion in the alkaline small intestine.
Q20. Which vitamin is made in the skin when exposed to sunlight?
- (A) Vitamin A
- (B) Vitamin C
- (C) Vitamin D
- (D) Vitamin B12
Show Answer
Answer: C – Sunlight on skin triggers vitamin D formation, which is needed for calcium absorption.
Q21. Which food component helps prevent constipation?
- (A) Saturated fat
- (B) Added sugar
- (C) Fibre
- (D) Salt
Show Answer
Answer: C – Fibre provides bulk that stimulates movement of food through the gut.
Transport in plants
Q22. Which cells control the opening and closing of stomata?
- (A) Guard cells
- (B) Palisade cells
- (C) Sieve cells
- (D) Epidermal cells without chloroplasts
Show Answer
Answer: A – Guard cells change shape as they gain or lose water, opening or closing the stomatal pore.
Q23. Which statement about water movement in a plant is correct?
- (A) Water enters through leaves only
- (B) Water moves from roots through xylem to leaves
- (C) Water moves in phloem to roots only in this context, when the other conditions are taken into account
- (D) Water is made in the stem
Show Answer
Answer: B – Roots absorb water, which travels up the xylem to the leaves where most is lost by transpiration.
Q24. Which adaptation reduces transpiration in a desert plant?
- (A) Large thin leaves in this context, when the other conditions are taken into account
- (B) Many open stomata
- (C) A thin cuticle
- (D) A thick waxy cuticle and sunken stomata
Show Answer
Answer: D – A thick cuticle and sunken stomata trap humid air and slow water loss from leaves.
Transport in animals
Q25. Which blood vessel carries blood from the heart to the body tissues?
- (A) Vena cava, which returns deoxygenated blood from the body to the right atrium
- (B) Aorta
- (C) Pulmonary vein
- (D) Pulmonary artery
Show Answer
Answer: B – The aorta is the largest artery and carries oxygenated blood from the left ventricle to the body.
Q26. Which part of the blood transports dissolved food, hormones and urea?
- (A) Plasma
- (B) Red blood cells
- (C) Platelets
- (D) Lymphocytes
Show Answer
Answer: A – Plasma is the liquid part of blood that carries solutes around the body.
Q27. Which heart valve prevents backflow between the right atrium and right ventricle?
- (A) Bicuspid valve
- (B) Aortic valve
- (C) Pulmonary valve in this context, when the other conditions are taken into account
- (D) Tricuspid valve
Show Answer
Answer: D – The tricuspid valve on the right side closes when the ventricle contracts, preventing backflow.
Diseases and immunity
Q28. Which type of immunity is gained by a baby from antibodies in breast milk?
- (A) Active natural immunity
- (B) Active artificial immunity
- (C) Passive natural immunity
- (D) Passive artificial immunity only
Show Answer
Answer: C – Antibodies passed naturally from mother to baby give passive natural immunity.
Q29. Which control measure helps prevent the spread of malaria?
- (A) Vaccinating against bacteria
- (B) Drinking boiled water only
- (C) Avoiding all outdoor activity
- (D) Using insecticide-treated bed nets
Show Answer
Answer: D – Treated nets kill or repel mosquitoes, reducing bites that transmit Plasmodium.
Q30. Which statement about pathogens is correct?
- (A) All bacteria cause disease
- (B) All fungi are harmful
- (C) A pathogen is a disease-causing organism
- (D) Viruses are larger than bacteria
Show Answer
Answer: C – Pathogens include certain bacteria, viruses, fungi and protoctists that cause disease.
Gas exchange in humans
Q31. Which change in the alveoli helps oxygen diffuse into the blood quickly?
- (A) A thick alveolar wall
- (B) A steep concentration gradient maintained by blood flow
- (C) A small total surface area
- (D) Dry alveolar surfaces
Show Answer
Answer: B – Blood flow carries oxygen away and brings carbon dioxide, keeping gradients steep for diffusion.
Q32. During inhalation, which muscles contract?
- (A) Diaphragm and external intercostal muscles
- (B) Diaphragm only, with ribs relaxing
- (C) Internal intercostal muscles only
- (D) Abdominal muscles only
Show Answer
Answer: A – Both sets contract to increase chest volume and draw air into the lungs.
Q33. Which statement about exhaled air is correct?
- (A) It contains no oxygen
- (B) It contains more carbon dioxide and water vapour than inhaled air
- (C) It contains more nitrogen than inhaled air
- (D) It is cooler and drier than inhaled air
Show Answer
Answer: B – Exhaled air gains carbon dioxide from respiration and water vapour from moist lung surfaces.
Respiration
Q34. Which process in cells uses oxygen and glucose?
- (A) Photosynthesis
- (B) Digestion
- (C) Transpiration
- (D) Aerobic respiration
Show Answer
Answer: D – Aerobic respiration breaks down glucose with oxygen to release energy.
Q35. Which energy-requiring process in a root uses energy from respiration?
- (A) Active uptake of mineral ions
- (B) Diffusion of oxygen
- (C) Osmosis of water
- (D) Transpiration pull
Show Answer
Answer: A – Active uptake moves ions against a gradient and therefore needs energy from respiration.
Q36. Which product builds up in muscle during anaerobic respiration and is later removed using oxygen?
- (A) Ethanol
- (B) Glucose
- (C) Lactic acid
- (D) Carbon dioxide only
Show Answer
Answer: C – Lactic acid accumulates during anaerobic respiration and is oxidised when oxygen becomes available.
Excretion in humans
Q37. Which organ produces urea from excess amino acids?
- (A) Kidney
- (B) Bladder
- (C) Liver
- (D) Pancreas
Show Answer
Answer: C – The liver deaminates excess amino acids and converts the nitrogen waste to urea.
Q38. Which substance is filtered out of the blood at the glomerulus but then reabsorbed?
- (A) Glucose
- (B) Red blood cells
- (C) Plasma proteins
- (D) Platelets
Show Answer
Answer: A – Glucose passes into the filtrate but is selectively reabsorbed in the tubule.
Q39. Which waste product is removed from the body in sweat?
- (A) Large amounts of protein
- (B) Glucose in large amounts
- (C) Faeces
- (D) Excess salts and water
Show Answer
Answer: D – Sweat mainly removes water and salts for cooling, with only small amounts of urea.
Coordination and response
Q40. Which effector produces movement in a reflex action?
- (A) Receptor
- (B) Muscle
- (C) Sensory neurone
- (D) Relay neurone
Show Answer
Answer: B – Muscles contract as effectors in most reflexes, while glands can also act as effectors.
Q41. Which hormone is released when blood glucose falls below normal?
- (A) Insulin
- (B) Oestrogen
- (C) Progesterone
- (D) Glucagon
Show Answer
Answer: D – Glucagon stimulates the liver to convert glycogen to glucose, raising blood glucose.
Q42. Which plant response is growth of roots downwards under gravity?
- (A) Phototropism
- (B) Geotropism
- (C) Chemotropism
- (D) Thigmotropism
Show Answer
Answer: B – Geotropism is growth in response to gravity, positive in roots and negative in shoots.
Drugs
Q43. Which substance in tobacco smoke damages the lining of airways and increases mucus?
- (A) Carbon monoxide
- (B) Nicotine
- (C) Tar
- (D) Oxygen
Show Answer
Answer: C – Tar damages cilia and airways, leading to mucus build-up and chronic bronchitis.
Q44. Which statement about drug addiction is correct?
- (A) The user feels a strong need to keep taking the drug
- (B) The user can stop at any time without effects
- (C) The drug has no effect on the brain
- (D) Tolerance never develops
Show Answer
Answer: A – Addiction involves craving and withdrawal, making it hard to stop despite harmful effects.
Q45. Which drug is commonly used to treat bacterial infections?
- (A) Antibiotic
- (B) Antiviral for all cases
- (C) Painkiller alone for cure
- (D) Vaccine as treatment
Show Answer
Answer: A – Antibiotics kill or inhibit bacteria, while vaccines prevent infections rather than treating them.
Reproduction
Q46. Which part of a flower produces pollen?
- (A) Stigma, the sticky surface that receives pollen during pollination
- (B) Ovary
- (C) Anther
- (D) Style
Show Answer
Answer: C – Pollen grains are produced in the anthers at the tips of the stamens.
Q47. Which structure in a seed provides food for the developing embryo?
- (A) Testa
- (B) Cotyledon or endosperm
- (C) Micropyle
- (D) Plumule alone
Show Answer
Answer: B – Cotyledons or endosperm store food that the embryo uses during germination.
Inheritance
Q48. In humans, which combination of sex chromosomes produces a female?
- (A) XY, the combination carried by a male and passed on through sperm cells
- (B) YY
- (C) X only
- (D) XX
Show Answer
Answer: D – A female has two X chromosomes, one inherited from each parent.
Q49. Which genotype shows a recessive phenotype for a single gene?
- (A) AA in this context, when the other conditions are taken into account
- (B) Aa
- (C) aa
- (D) AB
Show Answer
Answer: C – The recessive phenotype appears only when both alleles are recessive, as in aa.
Variation and selection
Q50. Which feature shows discontinuous variation in humans?
- (A) Weight
- (B) Blood group
- (C) Height
- (D) Skin shade range
Show Answer
Answer: B – Blood group falls into distinct categories and is controlled by a single gene.
Q51. Which process in meiosis contributes to variation?
- (A) Crossing over between homologous chromosomes
- (B) Identical division of cells
- (C) Cloning of gametes
- (D) Fusion of identical cells
Show Answer
Answer: A – Crossing over exchanges sections between chromosomes, creating new allele combinations.
Organisms and their environment
Q52. Which term describes the place where an organism lives?
- (A) Population
- (B) Community
- (C) Ecosystem
- (D) Habitat
Show Answer
Answer: D – A habitat is the place and conditions in which an organism lives.
Q53. Which sequence is a correct food chain?
- (A) Fox to rabbit to grass in this context, when the other conditions are taken into account
- (B) Rabbit to grass to fox
- (C) Grass to fox to rabbit
- (D) Grass to rabbit to fox
Show Answer
Answer: D – Energy flows from producer to primary consumer to secondary consumer in that order.
Q54. Which process in the carbon cycle removes carbon dioxide from the air?
- (A) Photosynthesis
- (B) Respiration
- (C) Combustion
- (D) Decomposition
Show Answer
Answer: A – Photosynthesis takes in carbon dioxide and fixes it into organic compounds in plants.
Human influences on ecosystems
Q55. Which farming practice can lead to eutrophication?
- (A) Crop rotation
- (B) Excess fertiliser washing into waterways
- (C) Hedgerow planting
- (D) Organic mulching only
Show Answer
Answer: B – Leached nitrate and phosphate enrich water, triggering algal blooms and oxygen depletion.
Q56. Which species is most at risk when a habitat is fragmented by roads?
- (A) A widespread generalist species
- (B) A migratory bird flying overhead
- (C) A small specialist species with a limited range
- (D) A fast-breeding weed species
Show Answer
Answer: C – Small, specialist populations are isolated by fragmentation, reducing breeding and increasing extinction risk.
Q57. Which conservation method protects species in their natural habitat?
- (A) Captive breeding only
- (B) In-situ conservation such as a national park
- (C) Seed banks only
- (D) Removing all predators permanently
Show Answer
Answer: B – In-situ conservation protects species where they live, preserving habitats and ecological interactions.
Biotechnology and genetic modification
Q58. Which product is made in a fermenter by the fungus Aspergillus for use in food production?
- (A) Citric acid
- (B) Insulin
- (C) Ethanol only
- (D) Penicillin only
Show Answer
Answer: A – Aspergillus niger is grown in fermenters to produce citric acid used as a food additive.
Q59. Which statement about genetic modification of plants is correct?
- (A) It always involves cross-pollination only
- (B) It changes the whole genome randomly
- (C) It adds or changes a specific gene for a desired trait
- (D) It makes plants unable to reproduce
Show Answer
Answer: C – Genetic modification targets a specific gene, for example for pest resistance or improved nutrition.
Q60. Which condition must be maintained in a fermenter for aerobic microorganisms?
- (A) No oxygen at all
- (B) Freezing temperatures
- (C) No stirring of the culture
- (D) A steady supply of oxygen and nutrients
Show Answer
Answer: D – Aerobic cultures need oxygen and nutrients, with stirring to distribute them and control temperature and pH.
Work through any questions you missed again, then revise those areas before moving on to the next test.
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