GCSE Biology Practice Test 3 – 60 Questions with Answers (AQA 8461)

Q1. A red blood cell is placed in concentrated salt solution. What happens?

• (A) It divides
• (B) It swells and bursts
• (C) It crenates (shrinks)
• (D) It stays the same

Q2. What is active transport?

• (A) Passive movement down a gradient
• (B) Movement against a concentration gradient using energy
• (C) Diffusion of water only
• (D) Movement through a fully permeable membrane

Q3. Root hair cells use active transport to take up which substances from soil?

• (A) Water only
• (B) Mineral ions such as nitrate
• (C) Oxygen only
• (D) Carbon dioxide

Q4. Which adaptation increases the surface area of a root hair cell?

• (A) A long thin extension
• (B) A large nucleus
• (C) A chloroplast
• (D) A thick cell wall

Q5. Which specialised cell has a long fibre to carry impulses quickly around the body?

• (A) Root hair cell
• (B) Nerve cell
• (C) Muscle cell
• (D) Egg cell

Q6. Why do red blood cells have a biconcave shape?

• (A) To divide quickly
• (B) To increase surface area for diffusion of oxygen
• (C) To store glucose
• (D) To fight pathogens

Q7. Which cell is adapted to carry electrical impulses?

• (A) Nerve cell
• (B) Sperm cell
• (C) Leaf cell
• (D) Muscle cell

Q8. What is the function of a sperm cell’s tail?

• (A) To protect DNA
• (B) To digest the egg
• (C) To swim towards the egg
• (D) To store food

Q9. What is the role of platelets?

• (A) To help blood clot
• (B) To carry hormones
• (C) To fight infection
• (D) To carry oxygen

Q10. What is plasma mainly made of?

• (A) Platelets
• (B) Fibrin
• (C) Red cells
• (D) Water with dissolved substances

Q11. Which blood vessels supply the heart muscle itself with oxygen?

• (A) Pulmonary vessels
• (B) Coronary arteries
• (C) Renal arteries
• (D) Carotid arteries

Q12. What is coronary heart disease?

• (A) Infection of the heart
• (B) Build-up of fatty material narrowing coronary arteries
• (C) Weakening of heart valves
• (D) Low blood pressure

Q13. Which treatment widens a blocked coronary artery using a balloon?

• (A) Dialysis
• (B) Bypass surgery
• (C) Stent insertion
• (D) Heart transplant

Q14. What does a heart bypass operation do?

• (A) Removes a valve
• (B) Stops the heart beating
• (C) Replaces the heart
• (D) Uses a vein to bypass a blocked artery

Q15. Which plant tissue carries water from roots to leaves?

• (A) Xylem
• (B) Mesophyll
• (C) Epidermis
• (D) Phloem

Q16. Which plant tissue carries sugars from leaves to other parts?

• (A) Cortex
• (B) Xylem
• (C) Phloem
• (D) Cambium

Q17. Why are drugs tested on animals before humans?

• (A) To check taste
• (B) To check for toxicity and effectiveness in a whole organism
• (C) To produce large amounts
• (D) To avoid paperwork

Q18. In a clinical trial, what is a placebo?

• (A) A vaccine
• (B) A double dose
• (C) An inactive dummy treatment
• (D) A new antibiotic

Q19. Why are clinical trials often double-blind?

• (A) So neither patients nor doctors know who has the real drug, reducing bias
• (B) To test two drugs at once
• (C) To include more patients
• (D) To save money

Q20. Which disease is spread by contaminated water?

• (A) HIV
• (B) Malaria
• (C) Measles
• (D) Cholera

Q21. Which is a physical barrier against infection?

• (A) White blood cells
• (B) Fever
• (C) Antibodies
• (D) Skin

Q22. What do platelets and phagocytes have in common?

• (A) Both are blood components involved in defence and repair
• (B) Both carry oxygen
• (C) Both produce hormones
• (D) Both make antibodies

Q23. Which plant defence is chemical?

• (A) Thorns
• (B) Thick bark
• (C) Antibacterial chemicals in leaves
• (D) Waxy cuticle

Q24. Which is a physical plant defence?

• (A) Making antibodies
• (B) Fever
• (C) Producing toxins
• (D) Thorns and waxy cuticle

Q25. What causes tobacco mosaic virus disease in plants?

• (A) A virus
• (B) A fungus
• (C) A protist
• (D) A bacterium

Q26. During vigorous exercise, muscles respire anaerobically and lactic acid builds up. What effect does this have?

• (A) It causes muscle fatigue and cramp
• (B) It increases the glucose supply to muscles
• (C) It cools the muscles
• (D) It stops breathing

Q27. Which substance is the main energy store in animals?

• (A) Cellulose
• (B) Glucose in blood only
• (C) Starch
• (D) Glycogen

Q28. What is metabolism?

• (A) The sum of all chemical reactions in a cell or body
• (B) Photosynthesis only
• (C) Movement of substances
• (D) Digestion only

Q29. Which is an example of an anabolic reaction?

• (A) Breaking down glucose in respiration
• (B) Digesting starch
• (C) Breaking down protein to amino acids
• (D) Building proteins from amino acids

Q30. What happens to excess amino acids in the body?

• (A) Stored as protein
• (B) Deaminated in the liver; the carbon part is used for respiration or stored
• (C) Excreted unchanged
• (D) Converted to starch

Q31. Which organ converts excess amino acids and makes urea?

• (A) Spleen
• (B) Kidney
• (C) Liver
• (D) Pancreas

Q32. Why do plants need light for photosynthesis but animals do not?

• (A) Animals photosynthesise at night
• (B) Plants cannot respire
• (C) Animals make chlorophyll
• (D) Plants use light energy to build glucose; animals obtain energy from food

Q33. A leaf is tested with iodine after being kept in darkness. What result is expected?

• (A) Blue-black throughout
• (B) Brown (no starch)
• (C) Yellow only
• (D) Red

Q34. Which part of a variegated leaf will test positive for starch after light exposure?

• (A) Green parts only
• (B) All parts equally
• (C) No parts
• (D) White parts only

Q35. Which is a treatment for type 1 diabetes?

• (A) Antibiotics
• (B) Removing the pancreas
• (C) Reducing sugar only
• (D) Insulin injections

Q36. Which hormone prepares the body for fight or flight?

• (A) Thyroxine
• (B) ADH
• (C) Insulin
• (D) Adrenaline

Q37. Which gland produces adrenaline?

• (A) Adrenal gland
• (B) Thyroid
• (C) Pancreas
• (D) Pituitary

Q38. A person with an overactive thyroid gland produces too much thyroxine. Which symptom is expected?

• (A) Slow heartbeat and weight gain
• (B) Always feeling cold
• (C) Fast heartbeat, restlessness and weight loss
• (D) Low blood glucose

Q39. What happens if thyroxine levels are too low?

• (A) Adrenaline rises
• (B) Metabolism speeds up
• (C) Metabolism slows, causing tiredness and weight gain
• (D) Blood glucose rises sharply

Q40. Which hormone is involved in negative feedback for thyroxine?

• (A) Insulin
• (B) ADH
• (C) Adrenaline
• (D) TSH from the pituitary

Q41. Which is the main female reproductive hormone that causes puberty changes?

• (A) Testosterone
• (B) Oestrogen
• (C) Progesterone only
• (D) Insulin

Q42. Which hormone maintains the uterus lining during the menstrual cycle?

• (A) Progesterone
• (B) LH
• (C) Oestrogen only
• (D) FSH

Q43. Which hormone stimulates ovulation?

• (A) Oestrogen
• (B) Progesterone
• (C) FSH
• (D) LH

Q44. Which variation is caused mainly by genes?

• (A) Scars
• (B) Muscle size from training
• (C) Language spoken
• (D) Blood group

Q45. Which variation is mainly environmental?

• (A) Blood group
• (B) Eye colour
• (C) A scar
• (D) Natural hair colour

Q46. Which feature shows discontinuous variation?

• (A) Mass
• (B) Skin shade across a range
• (C) Blood group
• (D) Leaf length

Q47. Which is an example of discontinuous variation?

• (A) Blood group
• (B) Height
• (C) Leaf length
• (D) Weight

Q48. A mutation in a gamete may be passed to offspring, but a mutation in a body cell usually is not. Why?

• (A) Body cells have no DNA
• (B) Only gametes pass DNA to the next generation
• (C) Body cells repair all mutations completely
• (D) Mutations only happen in gametes

Q49. Which agent can cause mutations?

• (A) Glucose
• (B) Water
• (C) Ultraviolet radiation
• (D) Oxygen

Q50. Antibiotic-resistant bacteria become common after repeated antibiotic use. How does natural selection explain this?

• (A) Resistant bacteria survive treatment, reproduce and pass on resistance alleles
• (B) Antibiotics create resistance in every bacterium they touch
• (C) Bacteria learn to ignore antibiotics
• (D) Weak bacteria mutate on purpose to become resistant

Q51. Which is the first step in evolution by natural selection?

• (A) Extinction
• (B) Variation within a population
• (C) Humans breeding animals
• (D) Migration only

Q52. Why do bacteria evolve antibiotic resistance quickly?

• (A) They learn
• (B) Antibiotics mutate them deliberately
• (C) They are large
• (D) They reproduce rapidly, so resistant mutants spread fast

Q53. How does combustion affect the carbon cycle?

• (A) It creates oxygen
• (B) It removes carbon dioxide
• (C) It releases carbon dioxide from fossil fuels
• (D) It fixes nitrogen

Q54. Which process converts nitrogen gas into compounds plants can use?

• (A) Denitrification
• (B) Nitrogen fixation by bacteria
• (C) Photosynthesis
• (D) Respiration

Q55. What do nitrifying bacteria do?

• (A) Fix nitrogen gas
• (B) Convert ammonia to nitrites and nitrates
• (C) Convert nitrates to nitrogen gas
• (D) Decompose proteins only

Q56. What do denitrifying bacteria do?

• (A) Fix carbon
• (B) Make ammonia
• (C) Make nitrates
• (D) Convert nitrates back to nitrogen gas

Q57. Why do farmers add fertiliser?

• (A) To replace nitrates and other minerals removed by crops
• (B) To increase water
• (C) To change soil pH only
• (D) To kill pests

Q58. Farm fertiliser washes into a lake. Which sequence follows?

• (A) Fish numbers rise and then algae die out
• (B) Nitrates enrich the water, algae bloom, light is blocked, plants die, decomposers use up oxygen, and fish die
• (C) The water becomes acidic and evaporates
• (D) Algae are eaten and the lake clears

Q59. How does deforestation increase carbon dioxide in the atmosphere?

• (A) It reduces respiration
• (B) It fixes nitrogen
• (C) Trees absorb less carbon dioxide and burning releases it
• (D) It increases photosynthesis

Q60. Which gas is a major greenhouse gas from burning fossil fuels?

• (A) Hydrogen
• (B) Oxygen
• (C) Carbon dioxide
• (D) Nitrogen