GCSE Biology Practice Test 12 – 60 Questions with Answers (AQA 8461)

Q1. A student looks at an animal cell and a bacterial cell under a microscope. Which difference will they observe?

• (A) Only the animal cell has a cell membrane
• (B) Only the bacterial cell has cytoplasm
• (C) Only the animal cell has ribosomes
• (D) Only the bacterial cell has a cell wall

Q2. How does a eukaryotic cell differ from a prokaryotic cell?

• (A) It has no cell membrane
• (B) It has no ribosomes
• (C) It has its DNA enclosed in a nucleus
• (D) It has DNA as a single loop only

Q3. A cell viewed under a microscope has an image size of 20 mm and an actual size of 0.02 mm. What is the magnification?

• (A) x100
• (B) x400
• (C) x1000
• (D) x2000

Q4. A specimen with an actual size of 0.05 mm appears 15 mm long in a micrograph. What is the magnification?

• (A) x30
• (B) x750
• (C) x300
• (D) x1500

Q5. An image is 40 mm long and the actual specimen is 0.08 mm long. What is the magnification?

• (A) x50
• (B) x320
• (C) x5000
• (D) x500

Q6. If a cell is 0.025 mm long in real life and its image is 25 mm long, what is the magnification?

• (A) x100
• (B) x250
• (C) x1000
• (D) x10000

Q7. Why does an electron microscope give a clearer image than a light microscope at high magnification?

• (A) It uses coloured light
• (B) It stains the specimen more strongly
• (C) It makes the specimen larger in real life
• (D) It has a much higher resolution

Q8. What is meant by resolution in microscopy?

• (A) The ability to distinguish between two points that are close together
• (B) The total size of the image
• (C) The brightness of the light used
• (D) The number of lenses in the microscope

Q9. Which type of microscope can be used to see a virus?

• (A) A light microscope at low power
• (B) A magnifying glass
• (C) An electron microscope
• (D) A telescope

Q10. Why do enzymes work faster up to their optimum temperature?

• (A) Enzymes are destroyed at low temperature
• (B) Particles move faster and collide more often
• (C) The substrate changes shape
• (D) The pH falls

Q11. What happens to an enzyme above its optimum temperature?

• (A) It works even faster forever
• (B) It becomes a substrate
• (C) Its active site changes shape and it is denatured
• (D) It turns into bile

Q12. What is meant by the lock and key model of enzyme action?

• (A) Any substrate fits any enzyme
• (B) Enzymes are unlocked by heat
• (C) The substrate fits exactly into the specific shape of the active site
• (D) The product opens the enzyme

Q13. Which part of the digestive system absorbs most digested food into the blood?

• (A) The stomach
• (B) The large intestine
• (C) The oesophagus
• (D) The small intestine, through villi

Q14. Which feature of a villus helps absorption?

• (A) A thick wall and no blood vessels
• (B) A cellulose wall
• (C) Many chloroplasts
• (D) A large surface area, a thin wall and a rich blood supply

Q15. What is absorbed in the large intestine?

• (A) Starch
• (B) Protein
• (C) Glucose into villi
• (D) Water

Q16. From which chamber is blood pumped out to the rest of the body?

• (A) The left ventricle
• (B) The right atrium
• (C) The right ventricle
• (D) The left atrium

Q17. Which vessel returns oxygenated blood from the lungs into the heart?

• (A) The pulmonary vein
• (B) The pulmonary artery
• (C) The vena cava
• (D) The aorta only

Q18. What do phagocytes do?

• (A) They produce antibodies only
• (B) They carry oxygen
• (C) They form blood clots
• (D) They engulf and digest pathogens

Q19. What is meant by immunity to a disease?

• (A) The ability of the body to resist infection by that pathogen
• (B) The ability to kill all bacteria in the body at once
• (C) A type of antibiotic
• (D) The production of extra red blood cells

Q20. Why does a person with a weakened immune system become ill more easily?

• (A) Because their body cannot fight pathogens effectively
• (B) Because they produce too many red blood cells
• (C) Because their blood clots too quickly
• (D) Because they cannot digest food properly

Q21. Which statement correctly compares bacteria and viruses?

• (A) Bacteria are living cells, while viruses are non-living particles that need a host cell to reproduce
• (B) Viruses are larger than bacteria
• (C) Bacteria need a host cell to reproduce
• (D) Both bacteria and viruses can be killed by antibiotics

Q22. What do memory cells allow?

• (A) Permanent production of red cells
• (B) Immunity to all diseases
• (C) A faster, stronger antibody response if the same pathogen returns
• (D) No need for white blood cells

Q23. Why does herd immunity help protect people who cannot be vaccinated?

• (A) Because vaccines kill pathogens in the air
• (B) Because unvaccinated people gain antibodies directly
• (C) Because pathogens cannot survive outside the body
• (D) Because fewer people carry and spread the pathogen

Q24. Why do antibiotics fail to cure viral infections?

• (A) Because viruses are too large
• (B) Because viruses live inside host cells and do not have the bacterial structures antibiotics target
• (C) Because antibiotics only work in the stomach
• (D) Because viruses are not pathogens

Q25. Why is it important to finish a full course of antibiotics?

• (A) So the patient becomes immune to viruses
• (B) So that all bacteria, including more resistant ones, are killed
• (C) So the antibiotic stays in the body forever
• (D) So red blood cells are replaced

Q26. Where does aerobic respiration mainly occur?

• (A) In mitochondria
• (B) In chloroplasts
• (C) In the vacuole
• (D) In the cell wall

Q27. What is the word equation for anaerobic respiration in muscle cells?

• (A) Glucose + oxygen -> carbon dioxide + water
• (B) Glucose -> lactic acid + energy
• (C) Glucose -> ethanol + carbon dioxide
• (D) Glucose -> oxygen + energy

Q28. Why does a brewer keep air out of the vessel when yeast ferments sugars?

• (A) So the yeast can photosynthesise
• (B) So the yeast stops respiring completely
• (C) So the yeast respires anaerobically and produces ethanol
• (D) So oxygen dissolves into the drink

Q29. Why does bread made with yeast not taste alcoholic?

• (A) Because yeast does not produce ethanol
• (B) Because the ethanol turns back into glucose
• (C) Because the ethanol evaporates during baking
• (D) Because baking adds oxygen to the dough

Q30. Why do muscles ache after intense exercise?

• (A) Too much oxygen is stored
• (B) Glucose is stored as starch in muscle
• (C) Carbon dioxide dissolves in muscle
• (D) Lactic acid builds up from anaerobic respiration

Q31. Why does anaerobic respiration release less energy per glucose molecule than aerobic respiration?

• (A) Because no glucose is used
• (B) Because glucose is only partly broken down, leaving energy in lactic acid
• (C) Because oxygen is produced
• (D) Because it takes place in chloroplasts

Q32. What happens to the rate of respiration as temperature rises towards the optimum?

• (A) It stays the same
• (B) It decreases steadily
• (C) It stops completely
• (D) It increases because enzyme activity increases

Q33. Why does heart rate increase during exercise?

• (A) To slow blood flow
• (B) To reduce breathing
• (C) To make more red blood cells instantly
• (D) To deliver oxygen and glucose to muscles faster and remove waste

Q34. What is meant by a tropism in plants?

• (A) A reflex action in animals
• (B) A growth response of a plant to a stimulus
• (C) The loss of water from leaves
• (D) The production of seeds

Q35. Which condition results when the pancreas makes little or no insulin?

• (A) Type 2 diabetes only
• (B) High blood pressure
• (C) Anaemia
• (D) Type 1 diabetes

Q36. In Type 2 diabetes, what often happens?

• (A) The pancreas makes too much insulin permanently
• (B) Body cells become less responsive to insulin
• (C) Blood glucose is always too low
• (D) The liver stops making glycogen

Q37. Where in the body are the adrenal glands found?

• (A) On top of the kidneys
• (B) In the brain
• (C) In the neck
• (D) In the pancreas

Q38. Where is adrenaline produced?

• (A) In the pancreas
• (B) In the pituitary gland
• (C) In the adrenal glands
• (D) In the thyroid gland

Q39. Which gland is known as the master gland?

• (A) The pituitary gland
• (B) The thyroid gland
• (C) The adrenal gland
• (D) The pancreas

Q40. Which hormone stimulates the growth of eggs and sperm production?

• (A) Progesterone only
• (B) Follicle stimulating hormone (FSH)
• (C) Insulin
• (D) Thyroxine

Q41. Which hormone triggers ovulation?

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

Q42. Which hormone maintains the uterus lining during pregnancy?

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

Q43. In a cross between two heterozygous parents (Aa x Aa), what proportion of offspring is expected to show the recessive phenotype?

• (A) One half
• (B) One quarter
• (C) Three quarters
• (D) All of them

Q44. In a cross Aa x Aa, what is the expected ratio of dominant to recessive phenotypes?

• (A) 1 : 1
• (B) 3 : 1
• (C) 1 : 2 : 1 for phenotypes
• (D) 4 : 0

Q45. A parent with genotype BB is crossed with bb. What are the genotypes of all offspring?

• (A) All BB
• (B) All bb
• (C) Half BB and half bb
• (D) All Bb

Q46. Cystic fibrosis is caused by a recessive allele. Two carriers (heterozygous) have a child. What is the chance the child has cystic fibrosis?

• (A) 1 in 2
• (B) 3 in 4
• (C) 1 in 8
• (D) 1 in 4

Q47. Polydactyly is caused by a dominant allele. A person with polydactyly who is heterozygous has a child with a person without the condition. What is the chance the child has polydactyly?

• (A) 1 in 2
• (B) 1 in 4
• (C) 3 in 4
• (D) 0

Q48. What is meant by discontinuous variation?

• (A) Variation caused only by the environment
• (B) Variation that shows a full range of values
• (C) Variation that falls into distinct categories with no intermediates
• (D) Differences between different species

Q49. Which characteristic shows only genetic variation?

• (A) Body mass
• (B) Height in humans
• (C) Blood group
• (D) Leaf size in shade

Q50. Which characteristic is affected mainly by environment?

• (A) Eye colour
• (B) Scars on skin
• (C) Blood group
• (D) Number of fingers at birth

Q51. Most variation in height is due to what?

• (A) Genes only
• (B) Environment only
• (C) A combination of genes and environment
• (D) Mutation only

Q52. Why is a pyramid of biomass usually pyramid-shaped?

• (A) Because top predators are larger
• (B) Because biomass decreases at higher levels due to energy loss
• (C) Because producers are always small
• (D) Because numbers always increase upwards

Q53. What is the role of decomposers?

• (A) To eat living producers
• (B) To break down dead organisms and waste, returning nutrients to soil
• (C) To photosynthesise
• (D) To hunt prey

Q54. Which organisms are decomposers?

• (A) Bacteria and fungi
• (B) Green plants
• (C) Herbivores
• (D) Carnivores

Q55. In the carbon cycle, how is carbon dioxide removed from the air?

• (A) By respiration
• (B) By combustion
• (C) By photosynthesis in plants
• (D) By decomposition

Q56. In the carbon cycle, how is carbon dioxide returned to the air?

• (A) By respiration, decomposition and combustion
• (B) By photosynthesis only
• (C) By feeding
• (D) By growth

Q57. What is the water cycle driven by?

• (A) Wind only
• (B) Energy from the Sun causing evaporation and condensation
• (C) Photosynthesis
• (D) Gravity only

Q58. What happens to water in the water cycle after precipitation?

• (A) It may run off, soak into soil, or be taken up by plants
• (B) It disappears permanently
• (C) It becomes carbon dioxide
• (D) It is stored as ice forever

Q59. What does the term biodiversity describe in an ecosystem?

• (A) The variety of different species and genes in an area
• (B) The number of predators only
• (C) The total biomass of producers
• (D) The variety of habitats only in a country

Q60. Why is high biodiversity important?

• (A) It reduces the number of food chains
• (B) It makes ecosystems more stable and resilient to change
• (C) It increases competition only
• (D) It makes extinction more likely