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Science questions, unit 4
Nama / NameKelas / ClassTarikh / Date

Interaction among living things

40 marks. Use Practice to check each answer as you go, or Exam to answer everything first. Ask a grown-up to help you mark the written answers.

Section A: objective questions

10 marks
Choose the best answer for each question.
1

Question 1

What is interaction among living things?
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C
Interaction among living things is a relationship among living things that depend on each other to obtain their basic needs.
For the teacher: Remembering, low difficulty, standard 4.1.1
Textbook p. 52
2

Question 2

In an oil palm plantation, an owl hunts a rat. What is the owl?
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B
An animal that hunts other animals for food is a predator. The rat is the prey.
For the teacher: Remembering, low difficulty, standard 4.1.1
Textbook p. 52
3

Question 3

Zebras and gnus drink at the same small water hole in the dry season. What type of interaction is this?
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A
Zebras and gnus are different species, so it is interspecies competition. They compete for water.
For the teacher: Understanding, low difficulty, standard 4.1.2
Textbook p. 55
4

Question 4

Two male mynahs fight near a female mynah. What are they competing for?
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D
Male mynahs of the same species compete for a female to mate with.
For the teacher: Understanding, low difficulty, standard 4.1.2
Textbook p. 54
5

Question 5

Which interaction is an example of commensalism?
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A
Barnacles get a free ride and the crab is not harmed or helped. The tick and cat is parasitism; the other two are mutualism.
For the teacher: Understanding, low difficulty, standard 4.1.3
Textbook p. 57
6

Question 6

A tapeworm lives in the intestine of a person and absorbs the food there. The person becomes ill. Which statement is correct?
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C
The tapeworm is the parasite and gains food. The person is the host and is harmed. This is parasitism.
For the teacher: Applying, medium difficulty, standard 4.1.3
Textbook p. 56
7

Question 7

Fifteen green bean seeds are planted 5 cm apart in pot A and another fifteen in pot B. The pots are the same size and get the same amount of water every day. Fertiliser is spread on the soil of pot B only. After three weeks the seedlings in pot B are healthier. Which factor causes the seedlings in pot A to compete?
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D
Everything is the same except the fertiliser. Without fertiliser, the seedlings in pot A have limited nutrients in the soil, so they compete for nutrients.
For the teacher: Applying, medium difficulty, standard 4.2.1
Textbook p. 61
8

Question 8

Why does the Rafflesia need to grow on a host plant?
A large red Rafflesia flower
Diagram 1
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D
Rafflesia cannot make its own food by photosynthesis. It absorbs water and nutrients from the host plant, which is harmed.
For the teacher: Understanding, low difficulty, standard 4.2.2
Textbook p. 62
9

Question 9

Farmers keep owls in an oil palm plantation. How do the owls help the ecosystem?
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A
Predators such as owls hunt rats. Prey-predator interaction controls the population of organisms.
For the teacher: Understanding, low difficulty, standard 4.2.3
Textbook p. 63
10

Question 10

The table shows three interactions between organisms. A plus sign (+) means the organism benefits, a cross (x) means it is harmed and a dash (-) means it is not affected.
InteractionOrganism 1Organism 2
P++
Q+x
R+-
Which row names the three interactions correctly?
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C
Both benefit in P (mutualism). One benefits and one is harmed in Q (parasitism). One benefits and the other is not affected in R (commensalism).
For the teacher: Analysing, medium difficulty, standard 4.1.3
Textbook p. 57

Section B: structured questions

30 marks
Answer all questions. Circle the answer or write it in the space.
11

Question 11

Diagram 2 shows a cheetah chasing a gazelle.
A cheetah chasing a gazelle
Diagram 2
[1 mark] (a)Name the predator.
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Tick each point you got.
[1 mark] (b)What is a prey?
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Tick each point you got.
[1 mark] (c)The Venus flytrap catches flies. Is the fly the prey or the predator?
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Prey
For the teacher: Remembering, low difficulty, standard 4.1.1
Textbook p. 52
12

Question 12

Hyenas fight over a piece of meat, and vultures compete with lions for the same food.
[1 mark] (a)The hyenas are competing with each other. Is this intraspecies or interspecies competition?
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Intraspecies
[1 mark] (b)What is the factor of competition in both cases?
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Tick each point you got.
[1 mark] (c)Why is the competition between vultures and lions called interspecies competition?
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Tick each point you got.
For the teacher: Understanding, low difficulty, standard 4.1.2
Textbook p. 54
13

Question 13

Diagram 3 shows a tick on a cat.
A tick enlarged next to a cat
Diagram 3
[1 mark] (a)Name the type of symbiosis between the tick and the cat.
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Tick each point you got.
[2 marks] (b)Which one is the parasite and which one is the host?
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Tick each point you got.
[1 mark] (c)A bird feeds on food stuck between a crocodile's teeth and the crocodile's teeth are cleaned. Both benefit. What type of symbiosis is this?
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Mutualism
[1 mark] (d)Remoras attach to a shark to get free transport and food scraps. The shark is not affected. What type of symbiosis is this?
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Commensalism
For the teacher: Understanding, low difficulty, standard 4.1.3
Textbook p. 57
14

Question 14

Aishah plants 10 green bean seeds in pot A and 3 seeds in pot B. Both pots are the same size, use the same soil and get the same amount of water every day. After three weeks she removes the seedlings and looks at the roots.
[1 mark] (a)What does Aishah change in this investigation?
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Tick each point you got.
[1 mark] (b)State one thing she keeps the same.
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Tick each point you got.
[1 mark] (c)State what she will observe about the roots.
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Tick each point you got.
[1 mark] (d)Give an inference for your answer in (c).
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Tick each point you got.
For the teacher: Applying, medium difficulty, standard 4.2.1
Textbook p. 60
15

Question 15

Diagram 4 shows living things in a pond.
A pond with water weeds, tadpoles, small fish and large fish
Diagram 4
[1 mark] (a)What do the large fish depend on the small fish for?
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Tick each point you got.
[1 mark] (b)All the small fish in the pond are removed. State what happens to the large fish.
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Tick each point you got.
[2 marks] (c)Explain why it is important that the large fish and small fish interact.
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Tick each point you got.
For the teacher: Analysing, medium difficulty, standard 4.2.3
Textbook p. 63
16

Question 16

Rats are eating the fruit in an oil palm plantation. A farmer says he will kill all the owls because they are noisy at night.
An oil palm plantation
Diagram 5
[1 mark] (a)Name the interaction between the owls and the rats.
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Tick each point you got.
[1 mark] (b)Is the farmer's idea a good one? Choose.
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No
[2 marks] (c)Give a reason for your answer in (b).
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Tick each point you got.
For the teacher: Evaluating, high difficulty, standard 4.2.3
Textbook p. 63
17

Question 17

Diagram 6 shows two plants. The bird's-nest fern grows on a large branch of a host plant. The Rafflesia grows on a host plant.
A bird's-nest fern on a host plant
Diagram 6(a): bird's-nest fern
A Rafflesia flower
Diagram 6(b): Rafflesia
[1 mark] (a)Which plant shows commensalism with its host?
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Bird's-nest fern
[1 mark] (b)Why is the host plant of the bird's-nest fern not harmed?
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Tick each point you got.
[2 marks] (c)Explain why the Rafflesia harms its host plant.
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Tick each point you got.
For the teacher: Understanding, low difficulty, standard 4.2.2
Textbook p. 62
18

Question 18

Choose the factor that makes the plants compete in each situation.
[1 mark] (a)Fifteen seedlings are crowded in a very small flowerpot.
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Space
[1 mark] (b)Seedlings in a box with a small hole at the top grow tall and thin towards the hole.
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Sunlight
[1 mark] (c)Seedlings in the pot without fertiliser grow weaker than those in the pot with fertiliser.
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Nutrients
For the teacher: Understanding, low difficulty, standard 4.2.1
Textbook p. 61