AI Generated Exam Paper
Primary 4 Science Practice Paper 3
Free P4 Science Practice Paper 3, Nemo3 AI version, with questions, answers, and syllabus-aligned practice for Singapore students.
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Questions
TuitionGoWhere Practice Paper - Science Primary 4
TuitionGoWhere Practice Paper (AI)
Subject: Science
Level: Primary 4
Paper: Practice Paper 3 (Version 3 of 5)
Duration: 1 hour 30 minutes
Total Marks: 100
Name: ________________________
Class: Primary 4 _______
Date: ________________________
Instructions to Candidates
- Do not open this booklet until you are told to do so.
- Follow all instructions carefully.
- Answer all questions.
- The number of marks is given in brackets [ ] at the end of each question or part question.
- For Section A, shade your answers on the Optical Answer Sheet (OAS) provided.
- For Section B and C, write your answers in the spaces provided in this booklet.
- The total marks for this paper is 100.
Section A: Multiple-Choice Questions (56 marks)
Questions 1 to 28 carry 2 marks each. For each question, four options are given. Choose the correct answer and shade the correct oval (1, 2, 3 or 4) on the Optical Answer Sheet.
1. Which of the following groups of living things are all classified as plants?
(1) Mushroom, moss, fern
(2) Algae, yeast, bacteria
(3) Hibiscus, balsam, orchid
(4) Mould, toadstool, bracket fungus
2. Study the classification chart below.
Generated diagram for Q2.
Which of the following living things is classified incorrectly in the chart?
(1) A whale is placed under Mammals.
(2) A spider is placed under Insects.
(3) A snake is placed under Reptiles.
(4) A frog is placed under Amphibians.
3. The diagram below shows a plant.
Generated diagram for Q3.
Which part, A, B, C, D or E, makes food for the plant?
(1) A
(2) B
(3) C
(4) D
4. Which of the following statements about fungi and bacteria is correct?
(1) Both fungi and bacteria make their own food.
(2) Both fungi and bacteria reproduce by spores.
(3) Fungi are non-living things but bacteria are living things.
(4) Yeast is a fungus but mould is a bacterium.
5. Study the flowchart below.
Generated diagram for Q5.
Organism X does not make its own food. It feeds on dead and decaying matter. It does not move from place to place. What is Organism X?
(1) Plant
(2) Fungus
(3) Animal
(4) Bacterium
6. Which of the following animals undergoes a four-stage life cycle (complete metamorphosis)?
(1) Grasshopper
(2) Cockroach
(3) Butterfly
(4) Chicken
7. The diagram below shows the life cycle of a mosquito.
Generated diagram for Q7.
At which stage does the mosquito live in water and breathe through a siphon tube at the water surface?
(1) Egg
(2) Larva
(3) Pupa
(4) Adult
8. Mei Ling observed a mealworm beetle over several weeks. She recorded her observations in the table below.
| Week | Observation |
|---|---|
| 1 | Small, white, oval-shaped eggs found in bran |
| 3 | Worm-like larvae seen eating bran |
| 6 | Larvae become motionless, covered in hard cases |
| 9 | Adult beetles emerge from cases |
Which of the following correctly matches the stage to the week?
(1) Week 1: Pupa
(2) Week 3: Adult
(3) Week 6: Larva
(4) Week 9: Adult
9. Which of the following statements about the life cycle of a flowering plant is correct?
(1) The seed grows into a seedling before germination occurs.
(2) Pollination occurs after fertilisation.
(3) The fruit develops from the ovary after fertilisation.
(4) Dispersal of seeds happens before pollination.
10. Study the diagram below showing the reproductive parts of a flower.
Generated diagram for Q10.
Which part produces pollen grains?
(1) P
(2) Q
(3) R
(4) S
11. The diagram below shows a human digestive system.
Generated diagram for Q11.
In which organ, A, B, C, D, E or F, is most of the digested food absorbed into the blood?
(1) A
(2) B
(3) C
(4) D
12. Which of the following shows the correct path of food through the human digestive system?
(1) Mouth → Stomach → Oesophagus → Small Intestine → Large Intestine → Anus
(2) Mouth → Oesophagus → Stomach → Small Intestine → Large Intestine → Anus
(3) Mouth → Oesophagus → Small Intestine → Stomach → Large Intestine → Anus
(4) Mouth → Stomach → Small Intestine → Oesophagus → Large Intestine → Anus
13. Ravi placed a piece of bread in his mouth and chewed it for 30 seconds before swallowing. He noticed the bread tasted sweeter after chewing. What is the reason for this?
(1) The teeth broke the bread into smaller pieces, releasing sugar.
(2) Saliva contains digestive juices that break down starch into simpler sugars.
(3) The tongue mixes the bread with air, causing a chemical change.
(4) Chewing increases the temperature of the bread, making it taste sweet.
14. Which of the following is a function of the large intestine?
(1) Digests proteins
(2) Absorbs water from undigested food
(3) Produces bile
(4) Stores faeces temporarily before removal
15. Study the classification table below.
| Group X | Group Y |
|---|---|
| Mushroom | Hibiscus |
| Yeast | Balsam |
| Mould | Orchid |
| Bracket fungus | Rose |
What are the headings for Group X and Group Y?
(1) Group X: Fungi, Group Y: Flowering Plants
(2) Group X: Bacteria, Group Y: Non-Flowering Plants
(3) Group X: Non-Flowering Plants, Group Y: Fungi
(4) Group X: Flowering Plants, Group Y: Fungi
16. The diagram below shows three types of microorganisms viewed under a microscope.
Generated diagram for Q16.
Which of the following statements is true?
(1) X, Y and Z are all fungi.
(2) X is a bacterium, Y is a fungus, Z is a fungus.
(3) X is a fungus, Y is a bacterium, Z is a fungus.
(4) X, Y and Z are all bacteria.
17. A seed needs air, water and warmth to germinate. Which of the following set-ups will allow the seed to germinate?
Generated experimental_setup for Q17.
(1) A
(2) B
(3) C
(4) D
18. The diagram below shows a young plant growing from a seed.
Generated diagram for Q18.
At which stage does the seedling start to make its own food?
(1) Stage 2
(2) Stage 3
(3) Stage 4
(4) Stage 5
19. Which of the following animals gives birth to live young and feeds its young with milk?
(1) Penguin
(2) Platypus
(3) Bat
(4) Crocodile
20. Study the flowchart below.
Generated diagram for Q20.
Animal P has dry scales and lays eggs with leathery shells. Which group does Animal P belong to?
(1) Amphibian
(2) Reptile
(3) Fish
(4) Mammal
21. The diagram below shows the life cycle of a frog.
Generated diagram for Q21.
Which stage breathes through gills and lives only in water?
(1) A
(2) B
(3) C
(4) D
22. Which of the following is NOT a characteristic of insects?
(1) Three body parts: head, thorax, abdomen
(2) Six legs
(3) Two pairs of wings (may be absent in some)
(4) Eight legs
23. The table below shows the characteristics of four organisms.
| Organism | Makes own food | Reproduces by spores | Feeds on dead matter |
|---|---|---|---|
| W | Yes | No | No |
| X | No | Yes | Yes |
| Y | No | No | No |
| Z | No | Yes | Yes |
Which organism is a bacterium?
(1) W
(2) X
(3) Y
(4) Z
24. In the human digestive system, where does digestion of food first begin?
(1) Stomach
(2) Small intestine
(3) Mouth
(4) Oesophagus
25. Which of the following statements about seed dispersal is correct?
(1) All seeds are dispersed by wind.
(2) Seeds dispersed by water have fibrous husks that trap air.
(3) Seeds dispersed by animals are always fleshy and sweet.
(4) Explosive dispersal only happens in flowering plants.
26. The diagram below shows a cross-section of a fruit.
Generated diagram for Q26.
Which part develops from the ovule after fertilisation?
(1) Fruit wall
(2) Seed
(3) Seed coat
(4) Embryo
27. A student wants to find out if light is needed for seed germination. Which two set-ups should he compare?
Generated experimental_setup for Q27.
(1) A and B
(2) A and C
(3) B and D
(4) C and D
28. Which of the following groups contains only vertebrates?
(1) Shark, salmon, whale
(2) Jellyfish, starfish, cuttlefish
(3) Earthworm, leech, tapeworm
(4) Spider, scorpion, crab
Section B: Structured Questions (24 marks)
Questions 29 to 34 carry 4 marks each. Write your answers in the spaces provided.
29. The diagram below shows a plant.
Generated diagram for Q29.
(a) Name the parts labelled A, B, C and D. [2]
A: ________________________
B: ________________________
C: ________________________
D: ________________________
(b) State the function of part C. [1]
(c) Part A has tiny hair-like structures. What is their function? [1]
30. Study the classification chart below.
Generated diagram for Q30.
(a) Write one example of a flowering plant and one example of a non-flowering plant in the boxes provided. [1]
(b) State two differences between vertebrates and invertebrates. [2]
Difference 1: _________________________________________________________________
Difference 2: _________________________________________________________________
(c) A bat has wings and can fly. Explain why a bat is classified as a mammal and not a bird. [1]
31. The diagram below shows the life cycle of a butterfly.
Generated diagram for Q31.
(a) Name the stages labelled 2 and 3. [1]
Stage 2: ________________________
Stage 3: ________________________
(b) State one difference between the caterpillar (Stage 2) and the adult butterfly (Stage 4) in terms of how they obtain food. [1]
(c) The pupa (Stage 3) does not eat or move much. Where does it get energy to develop into an adult? [1]
(d) The butterfly lays many eggs at a time. Explain why this is important for the survival of the species. [1]
32. The diagram below shows the human digestive system.
Generated diagram for Q32.
(a) In the table below, match each organ to its function by writing the correct letter (A, B, C, D, E or F) in the second column. [3]
| Function | Organ |
|---|---|
| Produces digestive juices that break down fats | |
| Absorbs water from undigested food | |
| Where most digestion and absorption of nutrients takes place |
(b) What happens to the undigested food after it leaves the small intestine? [1]
33. Siti conducted an experiment to find out the conditions needed for seed germination. She used four set-ups as shown below.
Generated experimental_setup for Q33.
(a) Which two set-ups should Siti compare to find out if air is needed for germination? [1]
Set-up ______ and Set-up ______
(b) In which set-up(s) will the seeds germinate? [1]
(c) Explain your answer in (b). [2]
34. The diagram below shows a flower.
Generated diagram for Q34.
(a) Name the parts labelled R and T. [1]
R: ________________________
T: ________________________
(b) After pollination, a pollen tube grows from the pollen grain. Where does the pollen tube grow to? [1]
(c) What happens during fertilisation in a flowering plant? [1]
(d) After fertilisation, the ovary develops into the fruit. What does the ovule develop into? [1]
Section C: Open-Ended Questions (20 marks)
Questions 35 to 38 carry 5 marks each. Write your answers in the spaces provided.
35. Ali found three unknown organisms, X, Y and Z, in his garden. He recorded his observations in the table below.
| Organism | Observation |
|---|---|
| X | Green, has leaves, makes its own food |
| Y | White, thread-like, grows on dead wood, reproduces by spores |
| Z | Moves from place to place, feeds on other organisms |
(a) Classify each organism as a plant, fungus, animal or bacterium. [3]
X: ________________________
Y: ________________________
Z: ________________________
(b) Organism Y is a mould. Explain how mould obtains its food. [1]
(c) State one way in which bacteria are different from fungi. [1]
36. The diagram below shows the life cycles of a grasshopper and a butterfly.
Generated diagram for Q36.
(a) The grasshopper has a three-stage life cycle while the butterfly has a four-stage life cycle. Name the stage present in the butterfly's life cycle but absent in the grasshopper's life cycle. [1]
(b) The young grasshopper (nymph) looks like the adult but is smaller and has no wings. The young butterfly (caterpillar) looks very different from the adult. Explain why the nymph does not need a pupal stage but the caterpillar does. [2]
(c) Both the grasshopper and the butterfly lay eggs. State one similarity and one difference between their eggs. [2]
Similarity: _________________________________________________________________
Difference: _________________________________________________________________
37. The diagram below shows a cross-section of the human digestive system.
Generated diagram for Q37.
(a) Digestion of starch begins in the mouth. Name the digestive juice in the mouth that digests starch. [1]
(b) The stomach produces gastric juice which contains acid. State two functions of the acid in the stomach. [2]
Function 1: _________________________________________________________________
Function 2: _________________________________________________________________
(c) Bile is produced by the liver and stored in the gall bladder. It is released into the small intestine. State the function of bile in digestion. [1]
(d) The inner wall of the small intestine has many tiny finger-like projections called villi. How do villi help in the absorption of digested food? [1]
38. Mrs Tan wants to grow a new plant from a cutting. She cuts a stem from a healthy balsam plant and places it in a beaker of water. After two weeks, roots grow from the cut end.
Generated experimental_setup for Q38.
(a) The stem cutting can grow roots and develop into a new plant. What characteristic of plants allows this to happen? [1]
(b) Mrs Tan noticed that the leaves on the cutting remained green and healthy during the two weeks. Explain how the leaves survived without roots at first. [2]
(c) After the roots have grown, Mrs Tan transfers the cutting into soil. State two functions of the roots in the soil. [2]
Function 1: _________________________________________________________________
Function 2: _________________________________________________________________
End of Paper
Answers
TuitionGoWhere Practice Paper - Science Primary 4 (Answer Key)
Subject: Science
Level: Primary 4
Paper: Practice Paper 3 (Version 3 of 5)
Total Marks: 100
Section A: Multiple-Choice Questions (56 marks)
1. Answer: (3) Hibiscus, balsam, orchid
Explanation: Hibiscus, balsam, and orchid are all flowering plants. Mushroom, mould, toadstool, and bracket fungus are fungi. Yeast is a fungus. Algae are plant-like but not true plants. Bacteria are microorganisms.
2. Answer: (2) A spider is placed under Insects.
Explanation: Spiders are arachnids (8 legs, 2 body parts), not insects (6 legs, 3 body parts). Whales are mammals, snakes are reptiles, frogs are amphibians — all correctly classified.
3. Answer: (3) C
Explanation: Part C is the leaf. Leaves contain chlorophyll and make food for the plant through photosynthesis. Roots absorb water/minerals, stems transport, flowers are for reproduction.
4. Answer: (2) Both fungi and bacteria reproduce by spores.
Explanation: Fungi reproduce by spores. Some bacteria form endospores for survival. Neither makes their own food (both are decomposers/parasites). Both are living things. Yeast is a fungus; mould is also a fungus.
5. Answer: (2) Fungus
Explanation: Following the flowchart: Does not make own food → feeds on dead/decaying matter → does not move → Fungus.
6. Answer: (3) Butterfly
Explanation: Butterfly undergoes complete metamorphosis (4 stages: egg, larva, pupa, adult). Grasshopper and cockroach have incomplete metamorphosis (3 stages: egg, nymph, adult). Chicken has a 3-stage life cycle (egg, chick, adult).
7. Answer: (2) Larva
Explanation: Mosquito larvae (wrigglers) live in water and breathe through a siphon tube at the water surface. Pupae also live in water but breathe through trumpets. Eggs are laid on water. Adults are terrestrial/flying.
8. Answer: (4) Week 9: Adult
Explanation: Week 1: Eggs. Week 3: Larvae. Week 6: Pupae (motionless in hard cases). Week 9: Adults emerge.
9. Answer: (3) The fruit develops from the ovary after fertilisation.
Explanation: Correct sequence: Pollination → Fertilisation → Ovary develops into fruit, ovule develops into seed. Germination occurs after seed dispersal.
10. Answer: (3) R
Explanation: R is the anther (part of stamen), which produces pollen grains. Stigma (S) receives pollen. Ovary (T) contains ovules.
11. Answer: (4) D
Explanation: D is the small intestine. Its inner wall has villi that greatly increase surface area for absorption of digested nutrients into the bloodstream.
12. Answer: (2) Mouth → Oesophagus → Stomach → Small Intestine → Large Intestine → Anus
Explanation: This is the correct anatomical sequence. Food passes from mouth to oesophagus (not directly to stomach), then stomach, small intestine, large intestine, anus.
13. Answer: (2) Saliva contains digestive juices that break down starch into simpler sugars.
Explanation: Saliva contains amylase, an enzyme that breaks down starch (complex carbohydrate) into maltose (simpler sugar), making the bread taste sweeter.
14. Answer: (2) Absorbs water from undigested food
Explanation: The large intestine's main functions are absorbing water and minerals from undigested food, and storing faeces temporarily. Protein digestion occurs in stomach/small intestine. Bile is produced by liver.
15. Answer: (1) Group X: Fungi, Group Y: Flowering Plants
Explanation: Mushroom, yeast, mould, bracket fungus are all fungi. Hibiscus, balsam, orchid, rose are all flowering plants.
16. Answer: (2) X is a bacterium, Y is a fungus, Z is a fungus.
Explanation: X shows rod-shaped bacteria. Y shows budding yeast cells (fungus). Z shows mould with hyphae and sporangia (fungus).
17. Answer: (3) C
Explanation: Germination needs air, water, warmth. A: no water. B: no air (sealed). C: has air, water, warmth (room temp). D: no warmth (freezer).
18. Answer: (4) Stage 5
Explanation: Stage 4 shows cotyledons (seed leaves) which may still have stored food. Stage 5 shows true leaves with chlorophyll — only then can the seedling photosynthesise and make its own food.
19. Answer: (3) Bat
Explanation: Bats are mammals — they give birth to live young and feed them milk. Penguins are birds (lay eggs). Platypus is a monotreme (egg-laying mammal). Crocodiles are reptiles (lay eggs).
20. Answer: (2) Reptile
Explanation: Following flowchart: No feathers → No hair/fur → No moist skin → Has dry scales → Reptile. Reptiles lay eggs with leathery shells.
21. Answer: (2) B
Explanation: Stage B (tadpole) has gills and lives only in water. Stage C develops legs but still has gills. Stage D (froglet) has lungs and shrinking tail. Stage E (adult) lives on land and in water.
22. Answer: (4) Eight legs
Explanation: Insects have 6 legs. Arachnids (spiders, scorpions) have 8 legs. Insects have 3 body parts, 2 pairs of wings (sometimes absent).
23. Answer: (3) Y
Explanation: W: makes own food = Plant. X: spores + dead matter = Fungus. Y: no own food, no spores, doesn't feed on dead matter, moves = Animal. Z: spores + dead matter = Fungus. Bacteria are microscopic, reproduce by binary fission (not spores typically), some decompose.
24. Answer: (3) Mouth
Explanation: Digestion begins in the mouth with mechanical (chewing) and chemical (salivary amylase) breakdown of starch.
25. Answer: (2) Seeds dispersed by water have fibrous husks that trap air.
Explanation: Water-dispersed seeds (e.g., coconut) have fibrous husks for buoyancy. Not all seeds are wind-dispersed. Animal-dispersed seeds can be hooked/spiny (not fleshy). Explosive dispersal occurs in some flowering plants (e.g., balsam, rubber tree).
26. Answer: (2) Seed
Explanation: After fertilisation: ovule → seed, ovary → fruit. The seed contains the embryo and seed coat (from integuments).
27. Answer: (1) A and B
Explanation: To test light, only light should vary. A (light) and B (dark) both have water, air, warmth. C lacks water. D lacks warmth.
28. Answer: (1) Shark, salmon, whale
Explanation: Shark (fish), salmon (fish), whale (mammal) are all vertebrates. Jellyfish, starfish, cuttlefish are invertebrates. Earthworm, leech, tapeworm are invertebrates. Spider, scorpion, crab are invertebrates (arthropods).
Section B: Structured Questions (24 marks)
29. (a) A: Roots, B: Stem, C: Leaves, D: Flowers [2]
Marking: 0.5 marks each correct label.
(b) Part C (leaves) makes food for the plant through photosynthesis. [1] Key concept: Leaves contain chlorophyll, trap light energy, convert CO₂ and H₂O to glucose.
(c) The tiny hair-like structures (root hairs) increase the surface area for absorption of water and mineral salts from the soil. [1] Key concept: Root hairs are extensions of epidermal cells, vastly increasing absorptive surface area.
30. (a) Flowering plant: e.g., Hibiscus / Balsam / Orchid / Rose. Non-flowering plant: e.g., Fern / Moss / Algae / Conifer. [1]
Marking: 0.5 each, any valid examples.
(b) Difference 1: Vertebrates have a backbone (vertebral column); invertebrates do not have a backbone. [1] Difference 2: Vertebrates have an internal skeleton (endoskeleton); invertebrates may have an external skeleton (exoskeleton) or
<stage5_exam_answers_md>
TuitionGoWhere Practice Paper - Science Primary 4 (Answer Key)
Subject: Science
Level: Primary 4
Paper: Practice Paper 3 (Version 3 of 5)
Total Marks: 100
Section A: Multiple-Choice Questions (56 marks)
| Question | Answer | Explanation |
|---|---|---|
| 1 | (3) | Hibiscus, balsam, and orchid are all flowering plants. Mushroom, mould, yeast, toadstool, bracket fungus are fungi. Algae is a plant-like protist; bacteria are microorganisms. |
| 2 | (2) | A spider is an arachnid (8 legs), not an insect (6 legs). Whale is a mammal, snake is a reptile, frog is an amphibian — all correct. |
| 3 | (3) | Part C (leaves) contains chlorophyll and makes food through photosynthesis. |
| 4 | (2) | Both fungi and bacteria reproduce by spores. Fungi and bacteria are living things; they do not make their own food. Yeast is a fungus; mould is also a fungus. |
| 5 | (2) | Organism X does not make its own food → not a plant. Feeds on dead/decaying matter → fungus. Does not move → not an animal. Bacteria do not typically feed on dead matter in this classification context. |
| 6 | (3) | Butterfly undergoes complete metamorphosis (4 stages: egg, larva, pupa, adult). Grasshopper and cockroach have 3-stage (incomplete) life cycles. Chicken has a 3-stage life cycle. |
| 7 | (2) | Mosquito larva lives in water and breathes through a siphon tube at the water surface. |
| 8 | (4) | Week 1: Egg; Week 3: Larva; Week 6: Pupa; Week 9: Adult. Only option (4) matches correctly. |
| 9 | (3) | After fertilisation, the ovary develops into the fruit. Germination occurs before seedling growth. Pollination occurs before fertilisation. Dispersal happens after fruit/seed formation. |
| 10 | (3) | Part R (anther) produces pollen grains. |
| 11 | (4) | Part D (small intestine) is where most digested food is absorbed into the blood. |
| 12 | (2) | Correct path: Mouth → Oesophagus → Stomach → Small Intestine → Large Intestine → Anus. |
| 13 | (2) | Saliva contains amylase, which breaks down starch into simpler sugars (e.g., maltose), making it taste sweeter. |
| 14 | (2) | The large intestine absorbs water from undigested food. It does not digest proteins, produce bile, or store faeces (rectum does). |
| 15 | (1) | Group X: Mushroom, Yeast, Mould, Bracket fungus → Fungi. Group Y: Hibiscus, Balsam, Orchid, Rose → Flowering Plants. |
| 16 | (2) | X (rod-shaped) = bacteria; Y (budding cells) = yeast (fungus); Z (hyphae & sporangia) = mould (fungus). |
| 17 | (3) | Set-up C has water (wet cotton wool), air (open dish), and warmth (room temperature) — all three conditions for germination. A lacks water; B lacks air (sealed) and warmth (fridge); D lacks warmth (freezer). |
| 18 | (4) | Stage 5: True leaves appear and contain chlorophyll, enabling photosynthesis. Cotyledons (Stage 4) store food but do not make food. |
| 19 | (3) | Bat is a mammal — gives birth to live young and feeds them milk. Penguin (bird), platypus (monotreme, lays eggs), crocodile (reptile) do not. |
| 20 | (2) | Dry scales + leathery eggshells = Reptile. |
| 21 | (2) | Stage B (tadpole) has gills and lives only in water. |
| 22 | (4) | Insects have six legs, not eight. Eight legs is a characteristic of arachnids. |
| 23 | (3) | Bacterium (Y): Does not make own food, does not reproduce by spores (binary fission), does not feed on dead matter (some do, but not a defining trait in this context). Fungi (X, Z): reproduce by spores, feed on dead matter. Plant (W): makes own food. |
| 24 | (3) | Digestion begins in the mouth (mechanical by teeth, chemical by salivary amylase). |
| 25 | (2) | Seeds dispersed by water (e.g., coconut) have fibrous husks that trap air for buoyancy. Not all seeds dispersed by wind; animal-dispersed seeds not always fleshy/sweet (some have hooks); explosive dispersal occurs in some non-flowering plants too. |
| 26 | (2) | The seed develops from the ovule after fertilisation. Fruit wall develops from ovary wall; seed coat from integuments; embryo from zygote. |
| 27 | (1) | To test light, compare A (light) and B (dark) — only light differs; both have water, air, warmth. |
| 28 | (1) | Shark (fish), salmon (fish), whale (mammal) — all vertebrates. Others are invertebrates. |
Section B: Structured Questions (24 marks)
29.
(a)
A: Roots
B: Stem
C: Leaves
D: Flowers
(b) Part C (leaves) makes food for the plant through photosynthesis.
(c) The tiny hair-like structures (root hairs) increase the surface area for absorption of water and mineral salts from the soil.
30.
(a)
Flowering plant: Hibiscus / Balsam / Orchid / Rose (any one)
Non-flowering plant: Fern / Moss / Algae / Conifer (any one)
(b)
Difference 1: Vertebrates have a backbone; invertebrates do not have a backbone.
Difference 2: Vertebrates have an internal skeleton (endoskeleton); invertebrates may have an external skeleton (exoskeleton) or hydrostatic skeleton.
(c) A bat has wings and hair/fur, so it is classified as a mammal, not a bird.
31.
(a) The life cycle of a mosquito has four stages: egg, larva, pupa, and adult.
(b) The larva and pupa stages live in water.
(c) To prevent mosquitoes from breeding, remove stagnant water (e.g., in flower pots, drains, containers) where they lay eggs.
32.
(a) The anther produces pollen grains which contain the male reproductive cells.
(b) Pollination is the transfer of pollen grains from the anther to the stigma of a flower.
(c) After fertilisation, the ovary develops into the fruit and the ovules develop into seeds.
33.
(a)
A: Mouth
B: Oesophagus
C: Stomach
D: Small intestine
E: Large intestine
(b) Digestion is completed in the small intestine (D).
(c) The large intestine (E) absorbs water from the undigested food, forming semi-solid faeces.
34.
(a) The seed leaves (cotyledons) store food for the young plant until it can make its own food.
(b) The seedling starts to make its own food when the first true leaves appear (Stage 5).
(c) The young plant gets its food from the cotyledons (seed leaves) before it can make its own food.
Section C: Open-Ended Questions (20 marks)
35.
(a) Fungi and bacteria are decomposers. They break down dead organisms and waste materials into simpler substances, returning nutrients to the soil for plants to use.
(b) Yeast is used in bread-making (causes dough to rise by producing carbon dioxide) and brewing (produces alcohol).
(c) Bacteria reproduce by binary fission (splitting into two), while fungi reproduce by spores.
36.
(a) The small intestine has a very long length, villi, and microvilli that greatly increase the surface area for absorption of digested food into the bloodstream.
(b) The stomach churns food and secretes gastric juice containing protease (to digest proteins) and hydrochloric acid (to kill bacteria and provide acidic pH for enzymes).
(c) The liver produces bile, which is stored in the gall bladder and released into the small intestine to emulsify fats (break large fat globules into smaller droplets) for faster digestion by lipase.
37.
(a) Wind dispersal: Seeds are light, small, and have wing-like structures or parachutes (e.g., dandelion, angsana).
Animal dispersal: Seeds have hooks/stiff hairs to cling on fur (e.g., love grass) OR are inside fleshy, sweet, brightly coloured fruits that are eaten (e.g., papaya, mango).
(b) Seed dispersal prevents overcrowding and reduces competition among young plants and the parent plant for light, water, space, and nutrients.
38.
(a) Similarity: Both life cycles have an egg stage and a young stage that looks different from the adult.
Difference: The mosquito has a pupa stage (complete metamorphosis, 4 stages); the grasshopper has no pupa stage — the young (nymph) resembles a small adult (incomplete metamorphosis, 3 stages).
(b) The nymph moults several times, growing larger each time, until it becomes an adult with fully developed wings.
End of Answer Key
Total: 100 marks
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