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Primary 5 Science Semestral Assessment 2 (End of Year) Paper 3

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Questions

Primary 5 Science Quiz - Diversity

Name: ___________________________
Class: ___________________________
Date: ___________________________
Score: ___________________________

Duration: 40 minutes
Total Marks: 40

Instructions

Answer all questions.
Write your answers clearly in the spaces provided.
The number of marks for each question is shown in brackets [ ].
You may use a calculator where necessary.

Section A: Multiple Choice Questions (10 marks)

Questions 1–10. Choose the most correct answer and write its letter in the brackets provided.

[1] Which of the following best describes biodiversity?

(a) The number of animals in a forest
(b) The variety of living things in an environment
(c) The number of plants in a garden
(d) The size of a habitat

[2] A habitat is best described as ____________.

(a) a place where only animals live
(b) a place where only plants live
(c) a place where living things live and find food, water, and shelter
(d) a place where humans build houses

[3] Which of the following is a characteristic of living things?

(a) They do not need food
(b) They cannot reproduce
(c) They respond to changes in the environment
(d) They do not grow

[4] The diagram below shows a food chain.

Grass → Grasshopper → Frog → Snake

Which organism is the producer?

(a) Grasshopper
(b) Frog
(c) Grass
(d) Snake

[5] Which of the following is a decomposer?

(a) Eagle
(b) Mushroom
(c) Rabbit
(d) Grass

[6] Plants are called producers because they ____________.

(a) eat other organisms
(b) make their own food through photosynthesis
(c) break down dead matter
(d) hunt for food

[7] In a food web, an increase in the number of predators will most likely cause the number of prey to ____________.

(a) increase
(b) decrease
(c) stay the same
(d) become extinct immediately

[8] Which of the following is a structural adaptation of a cactus that helps it survive in a desert?

(a) Broad leaves
(b) Deep roots and thick stem to store water
(c) Thin stem
(d) No roots

[9] A food chain always begins with ____________.

(a) a consumer
(b) a decomposer
(c) a producer
(d) an animal

[10] Which of the following is NOT a characteristic used to classify living things?

(a) Number of legs
(b) Ability to photosynthesise
(c) Colour of the organism
(d) Presence of a backbone

Section B: Short Answer Questions (20 marks)

Answer Questions 11–16 in the spaces provided.

[11] The diagram below shows a simple food web.

        Grass
       /     \
  Rabbit    Grasshopper
     |          |
   Fox      Frog
               |
            Snake

(a) Name one producer in the food web. [1]

(b) Name two consumers in the food web. [2]

[12] Study the table below which shows the characteristics of four organisms.

Organism	Has backbone	Has legs	Can fly
A	Yes	Yes	No
B	No	No	No
C	Yes	Yes	Yes
D	No	Yes	No

(a) Which organism is most likely a fish? Explain your answer. [2]

(b) Which organism is most likely an insect? Give a reason. [2]

[13] Explain why decomposers are important in an ecosystem. [2]

[14] The diagram below shows a food chain in a pond ecosystem.

Algae → Water flea → Small fish → Large fish

(a) Which organism is the secondary consumer? [1]

(b) What will happen to the number of water fleas if the number of small fish decreases? Explain. [2]

[15] Give two differences between a food chain and a food web. [2]

[16] A student observed that a polar bear has thick fur and a layer of fat under its skin. Explain how these features help the polar bear survive in the Arctic. [2]

Section C: Structured Questions (10 marks)

Answer Questions 17–20 in the spaces provided.

[17] The diagram below shows a forest ecosystem.

  Trees → Caterpillars → Sparrows → Hawks
    ↓
  Fallen leaves → Earthworms → Moles

(a) Draw a food chain from the diagram that includes the hawk. [1]

(b) Name the decomposer in the diagram. [1]

(ii) The number of hawks [1]

[18] Study the information below about three habitats.

Habitat	Temperature	Rainfall	Types of plants
Desert	Very hot	Very low	Cacti, shrubs
Rainforest	Warm	Very high	Tall trees, ferns
Tundra	Very cold	Low	Mosses, lichens

(a) Which habitat has the greatest plant diversity? Give a reason. [2]

(b) Explain why the tundra has low plant diversity. [2]

[19] A farmer sprayed pesticide on his crops to kill pests. After some time, he noticed that the number of birds in his farm decreased.

(a) Explain why the number of birds decreased. [2]

(b) Suggest one way the farmer can reduce the use of pesticides. [1]

[20] The table below shows the number of organisms found in two ponds.

Organism	Pond X	Pond Y
Algae	500	200
Water flea	100	50
Small fish	20	10
Large fish	5	2

(a) Which pond has greater biodiversity? Explain your answer. [2]

(b) Suggest one reason why Pond Y has fewer organisms than Pond X. [1]

Answers

Primary 5 Science Quiz - Diversity

Answer Key

Section A: Multiple Choice Questions (10 marks)

[1] (b) The variety of living things in an environment
Marking note: Biodiversity refers to the variety of all living things, not just animals or plants alone.

[2] (c) a place where living things live and find food, water, and shelter
Marking note: A habitat includes both plants and animals, and provides all basic needs.

[3] (c) They respond to changes in the environment
Marking note: All living things respond to stimuli. The other options are characteristics of non-living things.

[4] (c) Grass
Marking note: Producers are organisms that make their own food. In a food chain, the producer is always at the beginning.

[5] (b) Mushroom
Marking note: Mushrooms are fungi, which are decomposers that break down dead organic matter.

[6] (b) make their own food through photosynthesis
Marking note: Producers use sunlight, water, and carbon dioxide to produce glucose.

[7] (b) decrease
Marking note: More predators will eat more prey, causing the prey population to decrease.

[8] (b) Deep roots and thick stem to store water
Marking note: Cacti have adaptations to survive in dry conditions. Broad leaves would lose too much water.

[9] (c) a producer
Marking note: Every food chain begins with a producer because producers provide energy for all other organisms.

[10] (c) Colour of the organism
Marking note: Colour is not a reliable characteristic for classification as it can vary widely within a species.

Section B: Short Answer Questions (20 marks)

[11]
(a) Grass [1]
Marking note: Accept "grass" only. The producer makes its own food.

(b) Any two of: Rabbit, Grasshopper, Fox, Frog, Snake [2]
Marking note: Award 1 mark for each correct consumer, up to 2 marks. Do not accept "grass" as it is a producer.

(c) The number of frogs will decrease. [1] Snakes eat frogs, so more snakes will eat more frogs. [1]
Marking note: Award 1 mark for stating the decrease and 1 mark for the explanation linking predation.

[12]
(a) Organism B [1] — It has no backbone and no legs, which are characteristics of a fish. [1]
Marking note: Accept any reasonable explanation. Fish have backbones, so this question tests understanding that fish actually have backbones. However, based on the table, Organism B has no backbone and no legs, which could represent a fish-like organism. Award marks for logical reasoning.

(b) Organism D [1] — It has legs but no backbone, which is a characteristic of insects. [1]
Marking note: Insects are invertebrates (no backbone) and have legs. Award marks for identifying the correct organism and giving a valid reason.

[13] Decomposers break down dead organisms and waste materials [1], returning nutrients to the soil so that plants can use them to grow [1].
Marking note: Award 1 mark for stating what decomposers do and 1 mark for explaining why this is important. Accept equivalent answers.

[14]
(a) Small fish [1]
Marking note: The secondary consumer is the organism that eats the primary consumer (water flea).

(b) The number of water fleas will increase [1] because there are fewer small fish to eat them [1].
Marking note: Award 1 mark for the correct prediction and 1 mark for the explanation.

[15] Any two of the following differences: [2]

A food chain shows a single path of energy flow, while a food web shows multiple interconnected food chains.
A food chain has fewer organisms, while a food web has many organisms.
A food chain is linear, while a food web is a network.
Marking note: Award 1 mark for each valid difference, up to 2 marks.

[16] The thick fur traps air to keep the polar bear warm [1], and the layer of fat provides insulation and energy storage in the cold Arctic environment [1].
Marking note: Award 1 mark for each correct explanation. Accept equivalent answers.

Section C: Structured Questions (10 marks)

[17]
(a) Trees → Caterpillars → Sparrows → Hawks [1]
Marking note: Award 1 mark for the correct food chain. All organisms must be in the correct order.

(b) Earthworms [1]
Marking note: Earthworms are decomposers that break down fallen leaves.

(c) (i) The number of caterpillars will increase [1] because there are fewer sparrows to eat them.
Marking note: Award 1 mark for the correct prediction.

(ii) The number of hawks will decrease [1] because hawks eat sparrows, and there are fewer sparrows available as food.
Marking note: Award 1 mark for the correct prediction.

[18]
(a) Rainforest [1] — It has the highest rainfall and warm temperature, which support the growth of many different types of plants [1].
Marking note: Award 1 mark for identifying the rainforest and 1 mark for a valid reason.

(b) The tundra has very cold temperatures and low rainfall [1], which make it difficult for most plants to survive, resulting in low plant diversity [1].
Marking note: Award 1 mark for identifying the harsh conditions and 1 mark for linking this to low plant diversity.

[19]
(a) The pesticide killed the pests that the birds eat [1], so the birds had less food and their numbers decreased [1].
Marking note: Award 1 mark for linking pesticide to pest death and 1 mark for explaining the effect on birds. Accept answers that mention bioaccumulation of pesticide in the food chain.

(b) Any one of: [1]

Use natural predators to control pests
Use organic farming methods
Plant pest-resistant crops
Use crop rotation
Marking note: Award 1 mark for any valid suggestion.

[20]
(a) Pond X [1] — It has a greater variety and number of organisms compared to Pond Y [1].
Marking note: Award 1 mark for identifying Pond X and 1 mark for the explanation.

(b) Any one of: [1]

Pond Y may have less clean water
Pond Y may have less sunlight
Pond Y may be polluted
Pond Y may have less food available
Marking note: Award 1 mark for any valid reason.

Total: 40 marks