IGCSE Biology Practice Test 8 – 60 Questions with Answers (Cambridge 0610)
This test covers the full syllabus in order, so it is a useful check of how evenly your revision is spread across topics.
Characteristics and classification of living organisms
Q1. Which characteristic is shown when a plant grows towards light?
- (A) Excretion
- (B) Nutrition
- (C) Reproduction of new individuals
- (D) Sensitivity and movement
Show Answer
Answer: D – Growth towards light is a response to a stimulus, showing sensitivity, and involves movement.
Q2. Which organism is a fungus?
- (A) Yeast
- (B) Amoeba
- (C) Bacterium
- (D) Fern
Show Answer
Answer: A – Yeast is a single-celled fungus that feeds saprotrophically and reproduces by budding.
Organisation of the organism
Q3. Which level of organisation is formed by a group of similar cells working together?
- (A) Organism
- (B) Organ
- (C) Tissue
- (D) System
Show Answer
Answer: C – A tissue is a group of cells with a similar structure that work together for one function.
Q4. Which cell is specialised to carry impulses quickly?
- (A) Red blood cell
- (B) Neurone
- (C) Root hair cell
- (D) Palisade cell
Show Answer
Answer: B – Neurones have long fibres and insulating sheaths that speed up impulse transmission.
Movement into and out of cells
Q5. Which term describes a solution with the same water potential as cell sap?
- (A) Isotonic
- (B) Hypertonic
- (C) Hypotonic
- (D) Saturated
Show Answer
Answer: A – In an isotonic solution there is no net movement of water by osmosis.
Q6. Which surface is best adapted for rapid diffusion in the lungs?
- (A) Thick skin
- (B) Alveolar wall with capillaries
- (C) Stomach lining with many blood vessels
- (D) Leaf cuticle
Show Answer
Answer: B – The thin alveolar wall next to capillaries gives a short diffusion path and large area.
Biological molecules
Q7. Which test is used to detect the presence of starch?
- (A) Biuret test
- (B) Benedict’s test
- (C) Emulsion test
- (D) Iodine test
Show Answer
Answer: D – Iodine solution turns blue-black in the presence of starch.
Q8. Which molecule is a simple sugar and the main product of photosynthesis?
- (A) Starch
- (B) Cellulose
- (C) Glucose
- (D) Glycogen
Show Answer
Answer: C – Photosynthesis produces glucose, which may be stored as starch or used in respiration.
Q9. Which statement about lipids is correct?
- (A) They dissolve easily in water
- (B) They are made of amino acids joined in long chains
- (C) They store more energy per gram than carbohydrates
- (D) They are all solid at room temperature
Show Answer
Answer: C – Fats are energy-dense storage molecules, releasing more energy per gram than sugars.
Enzymes
Q10. Which statement about enzymes is always true?
- (A) They are used up in reactions and must be replaced constantly by cells
- (B) They only work inside cells
- (C) They work at any temperature
- (D) They are proteins that speed up reactions without being changed
Show Answer
Answer: D – Enzymes are biological catalysts, so they are not used up by the reaction they speed up.
Q11. What happens to an enzyme when it is denatured?
- (A) Its active site changes shape so the substrate no longer fits
- (B) It is permanently broken down into amino acids by protease enzymes acting in the stomach
- (C) It works faster at any temperature
- (D) It becomes a substrate itself
Show Answer
Answer: A – High temperature or extreme pH alters the active site shape, so the enzyme can no longer bind its substrate.
Q12. Lipase breaks down fats into which products?
- (A) Amino acids
- (B) Fatty acids and glycerol
- (C) Glucose only
- (D) Maltose and water from digestion
Show Answer
Answer: B – Lipase hydrolyses fats into fatty acids and glycerol for absorption.
Plant nutrition
Q13. Which equation summarises photosynthesis?
- (A) Carbon dioxide plus water to glucose plus oxygen
- (B) Glucose plus oxygen to carbon dioxide plus water
- (C) Glucose to ethanol plus carbon dioxide
- (D) Oxygen plus water to glucose
Show Answer
Answer: A – Photosynthesis uses light energy to combine carbon dioxide and water into glucose and oxygen.
Q14. Which part of a leaf contains most stomata?
- (A) Upper epidermis
- (B) Palisade layer
- (C) Lower epidermis
- (D) Midrib
Show Answer
Answer: C – Most stomata are on the lower surface, reducing water loss in direct sunlight.
Q15. Which ion is needed for making proteins in plants?
- (A) Magnesium ions
- (B) Nitrate ions
- (C) Calcium ions only
- (D) Potassium ions only
Show Answer
Answer: B – Nitrate ions supply nitrogen for amino acids, which are built into proteins.
Human nutrition
Q16. Which food group is the main source of energy in a balanced diet?
- (A) Proteins for growth
- (B) Vitamins
- (C) Minerals
- (D) Carbohydrates
Show Answer
Answer: D – Carbohydrates are the cheapest and most readily used energy source in the diet.
Q17. Which vitamin is made in the skin by sunlight and helps calcium absorption?
- (A) Vitamin A
- (B) Vitamin B
- (C) Vitamin D
- (D) Vitamin C
Show Answer
Answer: C – Vitamin D is produced in skin in sunlight and is needed for strong bones and teeth.
Q18. In which part of the gut does chemical digestion of proteins begin?
- (A) Mouth where chewing occurs
- (B) Ileum
- (C) Colon
- (D) Stomach
Show Answer
Answer: D – Pepsin in stomach acid begins breaking proteins into smaller peptides.
Transport in plants
Q19. Which cells absorb most water from the soil?
- (A) Root hair cells
- (B) Guard cells
- (C) Palisade cells
- (D) Sieve tube cells
Show Answer
Answer: A – Root hairs greatly increase surface area for water and ion uptake by osmosis and active transport.
Q20. What drives the upward movement of water in xylem vessels in a tall tree?
- (A) Root pressure alone
- (B) Transpiration pull from the leaves
- (C) Active transport by the phloem
- (D) Diffusion through the stomata only
Show Answer
Answer: B – Water lost by transpiration from leaves pulls a continuous column of water upwards through the xylem.
Q21. Which environmental change would reduce water uptake by a cut shoot in a potometer?
- (A) Brighter light
- (B) Stronger wind
- (C) Higher temperature
- (D) Higher humidity
Show Answer
Answer: D – Humid air slows transpiration, so the shoot takes up water more slowly.
Transport in animals
Q22. What is the function of red blood cells?
- (A) They carry oxygen around the body
- (B) They defend the body by engulfing pathogens and producing antibodies against infection
- (C) They help blood to clot
- (D) They transport hormones
Show Answer
Answer: A – Red blood cells contain haemoglobin, which binds oxygen in the lungs and releases it in the tissues.
Q23. Which blood vessel has the thinnest walls and allows exchange with tissues?
- (A) Artery with thick walls
- (B) Vein
- (C) Capillary
- (D) Aorta
Show Answer
Answer: C – Capillary walls are one cell thick, allowing diffusion between blood and tissues.
Q24. In a double circulation, how many times does blood pass through the heart in one complete circuit?
- (A) Once
- (B) Twice
- (C) Three times
- (D) Four times
Show Answer
Answer: B – Blood passes through the heart twice: once on the pulmonary circuit and once on the systemic circuit.
Diseases and immunity
Q25. Which organism causes malaria?
- (A) A bacterium spread by mosquitoes
- (B) A virus
- (C) A protoctist called Plasmodium
- (D) A fungus
Show Answer
Answer: C – Plasmodium is transmitted by female Anopheles mosquitoes and infects red blood cells.
Q26. Which method is the most effective way to prevent cholera spreading in a community?
- (A) Providing clean drinking water and sanitation
- (B) Taking antibiotics every day to prevent infection
- (C) Wearing a face mask
- (D) Avoiding all cooked food
Show Answer
Answer: A – Cholera spreads through contaminated water, so clean water and sewage treatment break transmission.
Q27. Which cells produce antibodies?
- (A) Red blood cells, which are made in the bone marrow and carry oxygen around the body
- (B) Platelets
- (C) Phagocytes
- (D) Lymphocytes
Show Answer
Answer: D – Lymphocytes make antibodies with a shape that fits a specific antigen on a pathogen.
Gas exchange in humans
Q28. Which gas diffuses from blood into alveolar air?
- (A) Oxygen
- (B) Carbon dioxide
- (C) Nitrogen
- (D) Water vapour only
Show Answer
Answer: B – Carbon dioxide is at a higher concentration in blood than in alveolar air, so it diffuses out.
Q29. Which feature increases the rate of gas exchange in alveoli?
- (A) Thick walls with a small surface area and a poor blood supply to the lungs
- (B) A single large air sac
- (C) Dry walls with no blood supply
- (D) A large surface area with a rich blood supply and thin walls
Show Answer
Answer: D – Millions of alveoli give a huge surface area, and thin, well-supplied walls allow rapid diffusion.
Q30. A piece of dry blue cobalt chloride paper turns pink when held in exhaled air. What does this show?
- (A) Oxygen, which is taken in during inhalation and used in aerobic respiration
- (B) Nitrogen
- (C) Water vapour
- (D) Carbon dioxide only
Show Answer
Answer: C – Cobalt chloride paper turns from blue to pink in the presence of water, and exhaled air is moist.
Respiration
Q31. Where in the cell does anaerobic respiration take place?
- (A) Cytoplasm
- (B) Mitochondrion, the organelle where most aerobic respiration takes place
- (C) Ribosome
- (D) Nucleus
Show Answer
Answer: A – Anaerobic respiration happens in the cytoplasm, without oxygen and without the mitochondria.
Q32. During anaerobic respiration in humans, glucose is broken down to which product?
- (A) Ethanol
- (B) Lactic acid
- (C) Carbon dioxide only
- (D) Oxygen
Show Answer
Answer: B – Human muscle respires anaerobically to lactic acid when oxygen supply is insufficient.
Q33. Which experiment would show that germinating seeds respire?
- (A) Testing leaves for starch
- (B) Measuring oxygen uptake only
- (C) Showing they release carbon dioxide and heat
- (D) Weighing seeds before and after
Show Answer
Answer: C – Respiring seeds release carbon dioxide, which turns limewater milky, and release heat.
Excretion in humans
Q34. Which substance is removed from blood by the kidneys and excreted in urine?
- (A) Oxygen
- (B) Platelets
- (C) Plasma proteins
- (D) Urea
Show Answer
Answer: D – Urea made in the liver is filtered from the blood by the kidneys and leaves the body in urine.
Q35. What happens to urea after it is made in the liver?
- (A) It is carried in blood to the kidneys and excreted in urine
- (B) It is stored in the bladder until it is broken down by bacteria in the large intestine
- (C) It is broken down in tubules
- (D) It leaves in faeces
Show Answer
Answer: A – Urea travels in the blood to the kidneys, where it is filtered out and leaves the body in urine.
Q36. Which condition would cause the kidney to produce a small volume of concentrated urine?
- (A) Drinking a large volume of water
- (B) Losing water through sweating on a hot day
- (C) Eating a meal low in salt
- (D) Sleeping for a short time
Show Answer
Answer: B – Water loss raises blood concentration, triggering antidiuretic hormone and more water reabsorption.
Coordination and response
Q37. Which structure detects light in the eye?
- (A) Lens
- (B) Retina
- (C) Cornea
- (D) Optic nerve only
Show Answer
Answer: B – Photoreceptor cells in the retina detect light and send impulses along the optic nerve.
Q38. Which hormone controls blood glucose after a meal high in carbohydrate?
- (A) Adrenaline
- (B) Thyroxine
- (C) Glucagon
- (D) Insulin
Show Answer
Answer: D – Insulin is released when blood glucose rises and promotes glucose uptake and glycogen storage.
Q39. A shoot grows towards light. Which hormone causes this response?
- (A) Auxin
- (B) Insulin
- (C) Adrenaline
- (D) Ethene
Show Answer
Answer: A – Auxin collects on the shaded side, causing faster elongation there and bending towards light.
Drugs
Q40. What happens to reaction time after a person drinks alcohol?
- (A) It becomes much faster
- (B) It stays exactly the same
- (C) It becomes slower
- (D) It only changes the next day
Show Answer
Answer: C – Alcohol slows the nervous system, so a person takes longer to respond to a stimulus.
Q41. Long-term smoking is most strongly linked to which disease?
- (A) Lung cancer
- (B) Diabetes
- (C) Malaria
- (D) Scurvy
Show Answer
Answer: A – Tar and other chemicals in smoke damage lung cells and greatly increase lung cancer risk.
Q42. Which of these drugs is classified as a stimulant?
- (A) Alcohol, a depressant that slows reactions and impairs judgement
- (B) Heroin
- (C) Solvents
- (D) Nicotine
Show Answer
Answer: D – Nicotine speeds up the nervous system, raising heart rate, and is the addictive substance in tobacco.
Reproduction
Q43. Which structure in the female reproductive system releases eggs?
- (A) Uterus, the muscular organ where the embryo implants and develops during pregnancy
- (B) Ovary
- (C) Urethra
- (D) Cervix
Show Answer
Answer: B – The ovaries contain follicles that release one egg cell each month after puberty.
Q44. In flowering plants, where are the female gametes found?
- (A) Anther
- (B) Pollen grain
- (C) Ovule inside the ovary
- (D) Petal
Show Answer
Answer: C – Each ovule contains an egg cell, which is fertilised by a pollen nucleus.
Q45. Which statement about sexual reproduction is correct?
- (A) Offspring are genetically different from both parents
- (B) Only one parent is involved
- (C) No gametes are produced
- (D) Offspring are identical clones
Show Answer
Answer: A – Fusion of two different gametes mixes genes, producing variation in offspring.
Inheritance
Q46. Which genotype is homozygous recessive for gene A?
- (A) AA
- (B) aa
- (C) Aa
- (D) A
Show Answer
Answer: B – Homozygous recessive means two copies of the recessive allele, written aa.
Q47. Which process produces haploid gametes?
- (A) Mitosis
- (B) Binary fission
- (C) Budding
- (D) Meiosis
Show Answer
Answer: D – Meiosis halves the chromosome number, producing haploid cells for sexual reproduction.
Q48. A child inherits a recessive allele for a condition from both parents, who do not show it. What can be said about the parents?
- (A) Both are homozygous dominant
- (B) Both are homozygous recessive
- (C) Both are heterozygous carriers
- (D) One parent has no allele
Show Answer
Answer: C – Carriers have one recessive allele hidden by a dominant allele and can pass it to children.
Variation and selection
Q49. Which factor causes variation that cannot be inherited?
- (A) Mutation in a gamete
- (B) A new allele combination
- (C) Crossing over in meiosis
- (D) Differences in diet during growth
Show Answer
Answer: D – Environmental factors such as diet affect phenotype but do not change the genes passed on.
Q50. Antibiotic resistance in bacteria is an example of which process?
- (A) Artificial selection by farmers
- (B) Natural selection
- (C) Asexual reproduction
- (D) Genetic engineering
Show Answer
Answer: B – Resistant bacteria survive antibiotic treatment and reproduce, spreading resistance genes.
Q51. Which statement about mutation is correct?
- (A) Mutations always improve survival
- (B) Mutations only occur in animals
- (C) Mutations are random changes in genes or chromosomes
- (D) Mutations are always caused by humans
Show Answer
Answer: C – Mutations arise randomly, for example from copying errors or radiation, and may be harmful, neutral or useful.
Organisms and their environment
Q52. Which organisms break down dead material and return nutrients to the soil?
- (A) Decomposers
- (B) Producers
- (C) Herbivores
- (D) Top carnivores
Show Answer
Answer: A – Bacteria and fungi decompose dead organisms, releasing nutrients for plants.
Q53. In a pyramid of numbers, why can a single tree support many herbivores?
- (A) The tree is a carnivore
- (B) One large producer provides enough food for many consumers
- (C) Herbivores do not eat trees
- (D) Trees reproduce quickly
Show Answer
Answer: B – A large producer has a huge biomass, so its pyramid of numbers can be inverted.
Q54. Which term describes all the organisms of one species living in an area at the same time?
- (A) Population
- (B) Ecosystem
- (C) Habitat
- (D) Community
Show Answer
Answer: A – A population is one species in an area, while a community includes all species there.
Human influences on ecosystems
Q55. Which human activity increases carbon dioxide in the atmosphere most directly?
- (A) Planting trees
- (B) Recycling glass
- (C) Using wind turbines
- (D) Burning coal in power stations
Show Answer
Answer: D – Burning fossil fuels releases carbon stored underground as carbon dioxide.
Q56. Which consequence of deforestation affects the water cycle?
- (A) More trees absorb rain
- (B) Soil becomes more stable
- (C) Less transpiration and more soil erosion and flooding
- (D) Rivers become deeper
Show Answer
Answer: C – Fewer trees mean less water returns to the air, and exposed soil washes into rivers.
Q57. Which measure helps protect endangered species?
- (A) Destroying their habitat for farming
- (B) Creating nature reserves and breeding programmes
- (C) Hunting them for trade
- (D) Introducing new predators
Show Answer
Answer: B – Reserves protect habitat, and captive breeding can rebuild populations for release.
Biotechnology and genetic modification
Q58. Which process uses yeast to make bread rise?
- (A) Photosynthesis
- (B) Digestion
- (C) Genetic modification
- (D) Anaerobic respiration producing carbon dioxide
Show Answer
Answer: D – Yeast respires anaerobically, and carbon dioxide bubbles make dough rise.
Q59. What is the role of ligase in genetic engineering?
- (A) It joins DNA fragments together
- (B) It cuts DNA open
- (C) It copies genes in a test tube
- (D) It destroys plasmids
Show Answer
Answer: A – Ligase seals the gene into the plasmid, forming recombinant DNA.
Q60. Which crop trait can be added by genetic modification?
- (A) Larger leaves only
- (B) Slower growth
- (C) Resistance to herbicide
- (D) Loss of seeds
Show Answer
Answer: C – Herbicide-resistant crops let farmers control weeds without killing the crop.
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