Total marks: 60 · Duration: 1 hour 15 minutes
Instructions to candidates
- This paper has 60 questions. Answer ALL questions.
- Each question is worth ONE mark.
- For each question there are four options, A, B, C and D. Choose the ONE you think is correct. In the January 2027 sitting, Paper 01 is taken online, so you select your answer on screen.
- The questions are grouped by syllabus section: Living Organisms in the Environment (1–15), Life Processes and Disease (16–45) and Continuity and Variation (46–60).
- You may use a silent, non-programmable electronic calculator.
Paper
Section A — Living Organisms in the Environment
1. Which group of organisms has a body made of thread-like hyphae and feeds by releasing enzymes onto its food?
A) Mosses
B) Bacteria
C) Fungi
D) Protoctists
2. Use this key. 1: Legs present → go to 2; no legs → earthworm. 2: Six legs → beetle; eight legs → spider. An animal with eight jointed legs is identified as a
A) earthworm
B) centipede
C) spider
D) beetle
3. Five 1 m² quadrats placed at random in a 200 m² field contain 3, 5, 4, 6 and 2 seedlings. The estimated number of seedlings in the field is
A) 1000
B) 4
C) 20
D) 800
4. Which of the following is an abiotic factor in a pond?
A) The number of predators
B) The pH of the water
C) A disease among the fish
D) Competition for food
5. The biomass at each trophic level of a food chain is smaller than the level below it MAINLY because
A) decomposers feed only at the top level
B) animals at higher levels are smaller in size
C) producers absorb only a little of the light
D) energy is lost as heat from respiration at each level
6. Which process removes carbon dioxide from the atmosphere?
A) Photosynthesis
B) Combustion
C) Decomposition
D) Respiration
7. In the nitrogen cycle, ammonium compounds in the soil are converted to nitrates by
A) nitrogen-fixing bacteria
B) nitrifying bacteria
C) putrefying fungi
D) denitrifying bacteria
8. A cattle tick feeds on the blood of a cow, which is harmed. This relationship is
A) predation
B) mutualism
C) commensalism
D) parasitism
9. In a food web, grass → grasshopper → lizard → hawk, and hawks also eat mice that feed on grass. If the hawks are hunted out, the lizard population will most likely first
A) decrease
B) increase
C) stay the same
D) die out
10. Fertiliser washes into a lake and causes an algal bloom. Some weeks later many fish die. The DIRECT cause of their death is
A) the water becoming too warm for the fish to survive
B) the fertiliser poisoning the fish as soon as it enters
C) bacteria using up dissolved oxygen as they decompose dead algae
D) the algae eating the fish eggs and young fish
11. Which greenhouse gas is released in large amounts by cattle and by flooded rice fields?
A) Nitrogen
B) Sulfur dioxide
C) Carbon monoxide
D) Methane
12. Acid rain is caused MAINLY by
A) carbon dioxide from the respiration of plants
B) methane released from landfill sites
C) sulfur dioxide and nitrogen oxides from burning fossil fuels
D) CFCs released from old refrigerators
13. Which measure would BEST help fish stocks on a Caribbean reef to recover?
A) Allowing the use of finer nets so that more fish are caught
B) Introducing a new predatory fish species to the reef
C) Setting up a marine protected area where fishing is banned
D) Building more hotels along the beach near the reef
14. Black mangroves grow pneumatophores that stick up out of the mud. Their MAIN function is to
A) store water for use in the dry season
B) take in oxygen for the respiration of the roots
C) anchor the tree firmly in the soft mud
D) absorb salt from the sea water around them
15. The first organisms to colonise bare rock after a volcanic eruption are usually
A) ferns
B) trees
C) lichens
D) grasses
Section B — Life Processes and Disease
16. In which organelle does aerobic respiration take place?
A) Chloroplast
B) Ribosome
C) Nucleus
D) Mitochondrion
17. Which part of a cell controls the movement of substances into and out of the cell?
A) Cytoplasm
B) Cell wall
C) Vacuole
D) Cell membrane
18. A strip of raw potato is left in a concentrated salt solution for an hour. It becomes
A) shorter and limp, as water leaves its cells by osmosis
B) longer and limp, as salt enters its cells by diffusion
C) unchanged, as potato cells have no membranes
D) longer and firm, as water enters its cells by osmosis
19. Active transport differs from diffusion because it
A) moves substances down a gradient
B) needs energy from respiration
C) moves only gases into cells
D) happens only in dead cells
20. An enzyme solution is boiled and then cooled. It no longer works because
A) its active site has permanently changed shape
B) it has been used up in the reaction
C) its substrate has evaporated
D) the cooling killed the enzyme cells
21. A food sample is heated with Benedict's solution, which turns brick-red. The food contains
A) fat
B) a reducing sugar such as glucose
C) protein
D) starch
22. Which are the raw materials for photosynthesis?
A) Oxygen and carbon dioxide
B) Oxygen and glucose
C) Glucose and water
D) Carbon dioxide and water
23. At a very low light intensity, adding more carbon dioxide to a plant has little effect on the rate of photosynthesis because
A) light is the limiting factor
B) the stomata are fully open
C) the plant has too much chlorophyll
D) carbon dioxide is toxic to plants
24. A child whose bones are soft and bend under the body's weight is most likely to be lacking
A) vitamin C
B) iron
C) vitamin D
D) iodine
25. Bile helps the digestion of fats by
A) emulsifying them into small droplets
B) absorbing them into the lacteals
C) making the small intestine acidic
D) breaking them into fatty acids and glycerol
26. The villi of the small intestine are adapted for absorption MAINLY because they
A) produce digestive enzymes
B) push food along by peristalsis
C) give a very large surface area
D) store glycogen for later use
27. A snack contains 20 g of carbohydrate (17 kJ per g) and 10 g of fat (39 kJ per g). How much energy does it provide?
A) 390 kJ
B) 730 kJ
C) 1120 kJ
D) 560 kJ
28. During a 400 m sprint, the leg muscles of an athlete produce
A) glucose by aerobic respiration
B) oxygen by aerobic respiration
C) ethanol by anaerobic respiration
D) lactic acid by anaerobic respiration
29. Gas exchange in the alveoli is efficient because the alveolar walls are
A) covered in thick mucus to trap dust
B) one cell thick, giving a short diffusion distance
C) made of cartilage to keep them open
D) lined with muscle to push air out
30. During inhalation, the diaphragm
A) contracts and flattens, increasing the chest volume
B) contracts and domes, decreasing the chest volume
C) relaxes and flattens, decreasing the chest volume
D) relaxes and domes, increasing the chest volume
31. Under which conditions would a plant lose water fastest by transpiration?
A) Cool, dry and still
B) Hot, dry and windy
C) Hot, humid and still
D) Cool, humid and still
32. Water and mineral ions are carried from the roots to the leaves in the
A) phloem
B) cortex
C) epidermis
D) xylem
33. Sucrose made in the leaves is transported to a growing fruit in the
A) stomata
B) xylem
C) root hairs
D) phloem
34. Which chamber of the heart has the thickest muscular wall?
A) Right atrium
B) Right ventricle
C) Left ventricle
D) Left atrium
35. Which blood vessel has valves and carries blood at low pressure?
A) Artery
B) Capillary
C) Arteriole
D) Vein
36. Which component of the blood helps it to clot at a cut?
A) Lymphocytes
B) Red blood cells
C) Plasma proteins only
D) Platelets
37. Urea is made in the liver from
A) excess amino acids
B) excess glucose
C) old red blood cells
D) stored fat
38. Glucose is found in the fluid filtered into the kidney tubule but not normally in urine because it is
A) used up by the bladder for energy
B) too large to pass into the tubule
C) reabsorbed into the blood further along the tubule
D) converted into urea in the kidney
39. Which of the following is an excretory product of plants?
A) Glucose stored in the fruit
B) Starch stored in the roots
C) Cellulose in the cell walls
D) Oxygen released during the day
40. Which function of the skeleton is carried out by the red bone marrow?
A) Making blood cells
B) Protecting the brain
C) Supporting the body
D) Storing water
41. When the biceps contracts to bend the arm, the triceps
A) becomes a ligament
B) contracts as well
C) relaxes
D) shortens
42. Which sequence shows the correct pathway of a reflex arc?
A) Sensory neurone → receptor → relay neurone → effector → motor neurone
B) Receptor → sensory neurone → relay neurone → motor neurone → effector
C) Receptor → motor neurone → relay neurone → sensory neurone → effector
D) Effector → motor neurone → relay neurone → sensory neurone → receptor
43. In bright light, the pupil becomes smaller because the
A) ciliary muscles relax
B) radial muscles of the iris contract
C) lens becomes thicker
D) circular muscles of the iris contract
44. Which hormone lowers the concentration of glucose in the blood?
A) Adrenaline
B) Glucagon
C) Insulin
D) Thyroxine
45. Malaria is spread from person to person by
A) female Anopheles mosquitoes
B) houseflies landing on food
C) droplets from coughs and sneezes
D) contaminated drinking water
Section C — Continuity and Variation
46. Mitosis produces
A) two cells genetically identical to the parent cell
B) two cells with different combinations of genes
C) four gametes that are all identical
D) four cells with half the number of chromosomes
47. How many chromosomes are there in a human egg cell?
A) 92
B) 23
C) 46
D) 22
48. In pea plants, tall (T) is dominant to short (t). A plant Tt is crossed with a plant tt. The expected ratio of offspring is
A) 1 tall : 1 short
B) all tall
C) 3 tall : 1 short
D) 1 tall : 3 short
49. An organism that has two different alleles of a gene, such as Bb, is described as
A) homozygous dominant
B) haploid
C) heterozygous
D) homozygous recessive
50. A mother with blood group A (genotype IᴬIᴼ) and a father with blood group B (genotype IᴮIᴼ) have a child. What is the probability that the child has blood group O?
A) 3 in 4
B) 1 in 2
C) 0
D) 1 in 4
51. The sex of a baby is determined by the father because
A) his sperm carry only Y chromosomes
B) his sperm carry either an X or a Y chromosome
C) the father produces more sperm than eggs
D) the mother's eggs carry only Y chromosomes
52. Sickle-cell anaemia is caused by
A) a virus that attacks red blood cells
B) a mutation in the gene for haemoglobin
C) too much vitamin C in the diet
D) a lack of iron in the diet
53. Which of the following shows continuous variation?
A) Height of students in a class
B) Blood group
C) Sex of a person
D) Ability to roll the tongue
54. Bacteria that are resistant to an antibiotic become more common when the antibiotic is overused. This is an example of
A) artificial selection
B) genetic engineering
C) natural selection
D) asexual mutation
55. A farmer grows bananas from suckers rather than seeds. One ADVANTAGE of this is that the new plants
A) are identical to a high-yielding parent
B) resist the diseases that killed the parent
C) show a lot of variation
D) need no water to grow
56. In a flower, pollen grains are produced by the
A) sepal
B) anther
C) ovary
D) stigma
57. Which feature is typical of an insect-pollinated flower?
A) Brightly coloured petals and nectar
B) Large amounts of light, smooth pollen
C) Small green petals or no petals
D) Feathery stigmas hanging outside
58. In humans, fertilisation normally takes place in the
A) oviduct
B) vagina
C) uterus
D) ovary
59. The MAIN function of the placenta is to
A) mix the blood of the mother with that of the fetus
B) protect the fetus from knocks with a cushion of fluid
C) exchange food, oxygen and wastes between mother and fetus
D) produce milk for the baby after birth
60. Human insulin for people with diabetes is now made by
A) feeding yeast large amounts of extra sugar
B) bacteria into which the human insulin gene has been inserted
C) crossing two breeds of cattle that make insulin
D) extracting it from the pancreas of human donors