IGCSE Biology Practice Test 4 – 60 Questions with Answers (Cambridge 0610)
Use this test to practise applying your knowledge to new situations, not just recalling facts.
Characteristics and classification of living organisms
Q1. A newly discovered organism has no nucleus and a single circular chromosome. Which kingdom does it belong to?
- (A) Animal with many specialised cells
- (B) Plant
- (C) Prokaryote
- (D) Fungus
Show Answer
Answer: C – Prokaryotes lack a nucleus and have free DNA in the cytoplasm.
Q2. Which feature distinguishes mammals from other vertebrates?
- (A) Laying eggs with shells
- (B) Having hair and mammary glands
- (C) Breathing through gills
- (D) Having a three-chambered heart and scaly skin
Show Answer
Answer: B – Hair and milk production are defining mammalian features.
Q3. Which pair belongs to the same class?
- (A) Frog and lizard
- (B) Shark and whale
- (C) Spider and beetle
- (D) Lizard and snake
Show Answer
Answer: D – Lizards and snakes are both reptiles.
Organisation of the organism
Q4. Which cell is specialised for carrying oxygen?
- (A) Red blood cell
- (B) White blood cell
- (C) Guard cell
- (D) Root hair cell
Show Answer
Answer: A – Red blood cells lack a nucleus, leaving more room for haemoglobin.
Q5. Ciliated cells line the airways. What is their job?
- (A) Absorbing nutrients
- (B) Moving mucus upwards
- (C) Producing hormones
- (D) Contracting the airway
Show Answer
Answer: B – Beating cilia sweep mucus with trapped particles towards the throat.
Q6. Which organ contains the largest number of villi?
- (A) Small intestine
- (B) Stomach
- (C) Large intestine
- (D) Oesophagus
Show Answer
Answer: A – Villi line the small intestine where absorption takes place.
Movement into and out of cells
Q7. Why do cells need active transport in addition to diffusion?
- (A) Diffusion is too fast for large molecules to use
- (B) Diffusion needs energy from respiration
- (C) Some substances must be taken up against a gradient
- (D) Osmosis cannot move water at all
Show Answer
Answer: C – Active transport moves molecules from low to high concentration using energy.
Q8. A cell placed in a solution of the same water concentration as its cytoplasm will:
- (A) Burst immediately
- (B) Shrink rapidly
- (C) Gain salt by osmosis
- (D) Stay the same size
Show Answer
Answer: D – Equal water potentials mean no net osmosis occurs.
Q9. Which process moves dissolved substances through a partially permeable membrane without energy?
- (A) Active transport
- (B) Translocation
- (C) Transpiration
- (D) Diffusion
Show Answer
Answer: D – Diffusion is the passive net movement down a concentration gradient.
Biological molecules
Q10. Which test result shows vitamin C is present?
- (A) Benedict’s solution stays blue after heating
- (B) Iodine stays brown
- (C) DCPIP solution loses its blue colour
- (D) Biuret solution stays blue
Show Answer
Answer: C – Vitamin C decolourises DCPIP, showing its presence.
Q11. Which molecule is formed from glycerol and three fatty acids?
- (A) A fat
- (B) A protein
- (C) A starch molecule
- (D) A DNA strand
Show Answer
Answer: A – Fats are esters of glycerol with fatty acids.
Q12. Why is starch a good storage molecule?
- (A) It dissolves easily and moves fast
- (B) It is insoluble and does not affect water balance
- (C) It is sweet and attracts animals
- (D) It breaks down without enzymes
Show Answer
Answer: B – Insoluble starch stores energy without disturbing osmosis.
Enzymes
Q13. A protease from the stomach is placed in the small intestine at pH 8. What happens to its activity?
- (A) It rises to a new optimum
- (B) It stays exactly the same
- (C) It is boosted by bile
- (D) It falls because the enzyme is denatured
Show Answer
Answer: D – Pepsin is adapted to acid and denatures in alkaline conditions.
Q14. Which statement explains the lock-and-key model?
- (A) Enzymes change shape to fit any substrate at all
- (B) Substrates break enzymes apart
- (C) Only a matching substrate fits the active site
- (D) Products block the enzyme permanently
Show Answer
Answer: C – The active site shape is complementary to one substrate type.
Q15. What happens to enzyme activity as temperature rises from 10 to 35 degrees Celsius?
- (A) It increases until the optimum is approached
- (B) It falls steadily from the start
- (C) It stays constant throughout
- (D) It stops at 20 degrees
Show Answer
Answer: A – More frequent energetic collisions raise the reaction rate below the optimum.
Plant nutrition
Q16. A plant shows poor root growth and weak stems. Which deficiency is most likely?
- (A) Magnesium deficiency
- (B) Phosphate deficiency
- (C) Nitrate deficiency
- (D) Iron deficiency
Show Answer
Answer: B – Phosphates are needed for roots, energy transfer and healthy growth.
Q17. Why do most leaves have stomata mainly on the lower surface?
- (A) To reduce water loss from direct sunlight
- (B) To prevent all gas exchange
- (C) To keep the leaf cool at night
- (D) To block insect damage
Show Answer
Answer: A – The shaded lower surface loses less water while still allowing gas exchange.
Q18. A variegated leaf is tested for starch after a day in light. Which part turns blue-black?
- (A) The white parts only
- (B) The veins only
- (C) The edges only
- (D) The green parts only
Show Answer
Answer: D – Only green, chlorophyll-containing regions can photosynthesise and make starch.
Human nutrition
Q19. Which vitamin deficiency causes scurvy?
- (A) Vitamin A
- (B) Vitamin C
- (C) Vitamin D
- (D) Vitamin B12
Show Answer
Answer: B – Vitamin C is needed for healthy skin, gums and connective tissue.
Q20. What is the main function of the large intestine?
- (A) Protein digestion
- (B) Fat emulsification
- (C) Absorption of water and vitamins
- (D) Production of bile
Show Answer
Answer: C – Remaining water is absorbed, forming faeces from undigested material.
Q21. Peristalsis is best described as:
- (A) Chewing food in the mouth
- (B) Rhythmic muscle contractions moving food along the gut
- (C) Absorption through villi
- (D) Secretion of stomach acid
Show Answer
Answer: B – Waves of contraction push food through the alimentary canal.
Transport in plants
Q22. Which tissue is found on the outside of a root and absorbs water?
- (A) Phloem
- (B) Xylem
- (C) Epidermis with root hairs
- (D) Cambium layer in the stem
Show Answer
Answer: C – The root epidermis bears hairs that increase absorbing surface.
Q23. Translocation differs from transpiration because translocation:
- (A) Moves water only upwards
- (B) Loses water vapour to air through stomata
- (C) Involves only dead xylem vessels
- (D) Moves sugars in phloem to sinks
Show Answer
Answer: D – Translocation carries dissolved sugars in living phloem to growing or storage tissues.
Q24. Which factor would decrease water uptake by a leafy shoot in a potometer?
- (A) High humidity around the leaves
- (B) Bright light on the leaves
- (C) Strong wind across the leaves all day
- (D) Warm air around the leaves
Show Answer
Answer: A – Humid air reduces the water vapour gradient, slowing transpiration.
Transport in animals
Q25. Why is the left ventricle wall thicker than the right?
- (A) It pumps blood to the lungs only at rest
- (B) It pumps blood around the whole body
- (C) It receives blood from the lungs
- (D) It contains more valves
Show Answer
Answer: B – Pumping to the whole body needs greater pressure than pumping to the lungs.
Q26. Which blood cells produce antibodies?
- (A) Red blood cells
- (B) Platelets
- (C) Plasma cells only in bone
- (D) Lymphocytes
Show Answer
Answer: D – Lymphocytes make specific antibodies against antigens.
Q27. What is tissue fluid?
- (A) Plasma that has leaked from capillaries bathing cells
- (B) Blood inside arteries
- (C) Lymph inside lymph nodes
- (D) Fluid inside the bladder
Show Answer
Answer: A – Tissue fluid forms from plasma and supplies cells before draining as lymph.
Diseases and immunity
Q28. Why is cholera more common where sewage mixes with drinking water?
- (A) Mosquitoes breed faster there
- (B) Cold weather preserves bacteria
- (C) Bacteria spread directly through contaminated water
- (D) People drink less water there
Show Answer
Answer: C – Ingesting contaminated water introduces the cholera bacterium.
Q29. Which body defence is described as mechanical?
- (A) Skin acting as a barrier
- (B) Antibody production
- (C) Stomach acid killing bacteria in the gut
- (D) Phagocytosis in blood
Show Answer
Answer: A – Intact skin physically blocks pathogen entry.
Gas exchange in humans
Q30. During gas exchange, oxygen moves from alveoli to blood because:
- (A) Blood actively pumps oxygen in
- (B) Alveoli contract to push gas out
- (C) Oxygen concentration is higher in alveoli than in blood
- (D) Carbon dioxide pushes oxygen across
Show Answer
Answer: C – Diffusion follows the concentration gradient into the capillary blood.
Q31. Which feature increases the rate of gas exchange in the lungs?
- (A) Thick alveolar walls
- (B) Slow blood flow only
- (C) Small total lung volume
- (D) A very large alveolar surface area
Show Answer
Answer: D – Millions of alveoli provide a huge surface for diffusion.
Respiration
Q32. A respirometer shows oxygen uptake falls when a poison blocks mitochondria. What does this prove?
- (A) Mitochondria store oxygen gas
- (B) Aerobic respiration needs mitochondria
- (C) Anaerobic respiration uses oxygen
- (D) Photosynthesis occurs in mitochondria of leaf cells
Show Answer
Answer: B – Blocking mitochondria stops aerobic respiration and oxygen consumption.
Q33. Which product is common to both aerobic and anaerobic respiration in yeast?
- (A) Lactic acid
- (B) Oxygen
- (C) Carbon dioxide
- (D) Ethanol in both cases
Show Answer
Answer: C – Yeast produces carbon dioxide in both modes, though energy yield differs.
Excretion in humans
Q34. Which process in the kidney removes urea from blood?
- (A) Selective reabsorption
- (B) Ultrafiltration
- (C) Active transport of glucose
- (D) Secretion of bile
Show Answer
Answer: B – Ultrafiltration forces urea and other small molecules out of the blood.
Q35. Why does the kidney reabsorb glucose?
- (A) Glucose is a valuable energy source worth keeping
- (B) Glucose is toxic in the bladder
- (C) Glucose cannot pass the filter
- (D) Glucose is needed to make urine
Show Answer
Answer: A – The body conserves glucose rather than losing it in urine.
Q36. Which organ excretes carbon dioxide and water vapour?
- (A) Kidney
- (B) Skin only
- (C) Liver
- (D) Lung
Show Answer
Answer: D – Lungs excrete gaseous waste from respiration.
Coordination and response
Q37. Which sequence is correct for a simple reflex?
- (A) Effector, motor neurone, CNS, sensory neurone, receptor
- (B) Receptor, CNS, sensory neurone, effector
- (C) Sensory neurone, motor neurone, effector
- (D) Receptor, sensory neurone, CNS, motor neurone, effector
Show Answer
Answer: D – Impulses travel from receptor to effector via the CNS.
Q38. What is the role of the cornea?
- (A) Refracting light into the eye
- (B) Detecting colour
- (C) Carrying impulses to the brain
- (D) Controlling pupil size
Show Answer
Answer: A – The cornea provides most of the eye’s focusing power.
Q39. In dim light, the pupil dilates because:
- (A) Radial muscles relax fully in dim light
- (B) The lens thickens
- (C) Radial muscles of the iris contract
- (D) The retina shrinks
Show Answer
Answer: C – Radial muscle contraction pulls the iris outward, widening the pupil.
Drugs
Q40. Which statement about alcohol is correct?
- (A) It improves reaction time
- (B) It slows reactions and impairs judgement
- (C) It increases oxygen in blood
- (D) It strengthens the liver
Show Answer
Answer: B – Alcohol is a depressant that slows the nervous system.
Q41. Why is heroin dangerous even in small doses?
- (A) It causes instant blindness
- (B) It dissolves red blood cells
- (C) It can depress breathing to fatal levels
- (D) It blocks all digestion
Show Answer
Answer: C – Depressant action on the brain can slow breathing dangerously.
Q42. Which of these is a legal drug that can still harm health?
- (A) Heroin
- (B) Tobacco
- (C) Cocaine
- (D) LSD
Show Answer
Answer: B – Tobacco is legal in many places yet causes serious disease.
Reproduction
Q43. Which structure in the male reproductive system produces sperm?
- (A) Prostate gland
- (B) Sperm duct
- (C) Urethra
- (D) Testis
Show Answer
Answer: D – Sperm are produced in the seminiferous tubules of the testes.
Q44. What is the function of the amniotic fluid?
- (A) To cushion and protect the fetus
- (B) To digest nutrients for the fetus
- (C) To produce hormones only
- (D) To supply oxygen directly
Show Answer
Answer: A – The fluid absorbs shocks and keeps temperature stable around the fetus.
Q45. Which method spreads a plant without seeds and keeps the parent’s traits?
- (A) Taking stem cuttings
- (B) Cross-pollination
- (C) Self-pollination
- (D) Growing from pollen alone
Show Answer
Answer: A – Cuttings grow by mitosis, producing genetically identical plants.
Inheritance
Q46. A man with genotype XY has a child. Which parent determines the child’s sex?
- (A) The mother only, through the egg cell alone
- (B) Neither parent, by chance alone
- (C) The environment after birth
- (D) The father, through the X or Y sperm
Show Answer
Answer: D – Eggs always carry X, while sperm carry X or Y.
Q47. What is meant by a heterozygous genotype?
- (A) Two identical alleles for a gene
- (B) Two different alleles for a gene
- (C) No alleles for a gene
- (D) Three alleles for a gene
Show Answer
Answer: B – Heterozygous means the two alleles differ, for example Aa.
Q48. Which process creates new combinations of alleles in gametes?
- (A) Mitosis only
- (B) Fertilisation only
- (C) Meiosis, including independent assortment
- (D) Cloning
Show Answer
Answer: C – Meiosis shuffles alleles into varied gamete combinations.
Variation and selection
Q49. Which statement best defines evolution?
- (A) Change in allele frequencies in a population over time
- (B) Sudden change in one individual
- (C) Migration of animals each season
- (D) Growth of an individual organism
Show Answer
Answer: A – Evolution is a population-level change in gene frequencies across generations.
Q50. A population of insects is sprayed with insecticide. Most die, but a few survive and breed. What is this?
- (A) Artificial selection only by human breeders
- (B) Genetic engineering
- (C) Natural selection for resistance
- (D) Asexual reproduction
Show Answer
Answer: C – Resistant insects survive the selection pressure and pass on resistance.
Q51. Which type of variation is usually controlled by a single gene?
- (A) Height
- (B) Discontinuous variation
- (C) Body mass
- (D) Skin colour shade in different populations
Show Answer
Answer: B – Discontinuous traits fall into clear groups and are often single-gene.
Organisms and their environment
Q52. Which term describes all the interacting living and non-living factors in an area?
- (A) Population
- (B) Community
- (C) Habitat
- (D) Ecosystem
Show Answer
Answer: D – An ecosystem includes the community plus its physical environment.
Q53. Why do pyramids of energy always narrow upwards?
- (A) Producers are eaten first
- (B) Consumers reproduce slowly
- (C) Energy is always gained at each level of the pyramid
- (D) Energy is lost as heat and waste at each level
Show Answer
Answer: D – Losses mean less energy remains for the next trophic level.
Q54. In a food web, a hawk eats both rabbits and mice. What happens if rabbits decline?
- (A) The hawk must starve completely without rabbits
- (B) The hawk may eat more mice instead
- (C) Mice populations must fall too
- (D) Grass biomass must fall
Show Answer
Answer: B – Alternative prey buffers predators against one prey declining.
Human influences on ecosystems
Q55. Which action reduces the carbon footprint of transport?
- (A) Using public transport or cycling
- (B) Flying more often
- (C) Burning more petrol
- (D) Driving alone for short trips every day
Show Answer
Answer: A – Shared transport and cycling use far less fuel per person.
Q56. What is habitat destruction?
- (A) Seasonal migration of animals
- (B) Natural ageing of trees
- (C) Loss of the place where an organism lives
- (D) Growth of a new forest
Show Answer
Answer: C – When habitats are cleared, species lose food, shelter and breeding sites.
Q57. Why is deforestation a problem for biodiversity?
- (A) It creates more farmland only
- (B) It removes habitats and food sources for many species
- (C) It increases soil fertility forever
- (D) It cools the climate locally
Show Answer
Answer: B – Forest species depend on trees for shelter and food webs.
Biotechnology and genetic modification
Q58. Which enzyme is used to cut DNA at specific points in genetic engineering?
- (A) Restriction enzyme
- (B) Amylase
- (C) Lipase
- (D) Protease that digests proteins
Show Answer
Answer: A – Restriction enzymes cut DNA at recognised base sequences.
Q59. What is a fermenter?
- (A) A microscope for bacteria
- (B) A filter for pure water
- (C) A vessel for growing microorganisms under controlled conditions
- (D) A freezer for storing genes
Show Answer
Answer: C – Fermenters control temperature, pH and nutrients for maximum yield.
Q60. Which is a benefit of using bacteria to make medicines?
- (A) Bacteria work only at freezing temperatures
- (B) Bacteria need no food source
- (C) Bacteria produce identical human proteins slowly
- (D) Bacteria can produce large amounts quickly and cheaply
Show Answer
Answer: D – Fast bacterial growth gives high yields at relatively low cost.
Work through any questions you missed again, then revise those areas before moving on to the next test.
📥 Prefer pen and paper? Take this test offline.
Download Printable PDF – Test 4
Free printable version: all 60 questions + answer key. Explanations stay here on the website.