Hands-on Science Workbook Primary 4 (Chapter 01)

Chapter Life Cycles

1

1.1 Life Cycles of Animals

1 The diagram shows the life cycle of a butterfly. Name the stages below.

(a) (b)

(d) (c)

2 Answer the questions based on the life cycle shown in Question 1. 1
(a) How does the butterfly reproduce?


(b) In which stage does the butterfly stop eating?


(c) In which stage does the butterfly become a pest to farmers?


(d) What other animal has a similar life cycle with the butterfly?



Chapter 1
Life Cycles

3 The diagram below shows the life cycle of a praying mantis. Name the stages
below.
(b)

(a)

(c)

1.2 Life Cycles of Plants

4 The diagram below shows the life cycle of a plant. Name the stages (a) to (c)
below. Then, fill in the blanks.

Suitable conditions for
(a) germination would be air,

water and .

(c) (b)
The developed
flowers will produce Starts making its own food
fruits filled with as the
are formed.
.

2 Primary 4
Hands-on Science

Objective Questions 4 In which stage of the life cycle
would a butterfly, a beetle and a
Choose the best answer. mosquito molt a few times as they
grow?
1 What is the first stage in the life
cycle of many insects and some A Adult
animals?
A A nymph B Nymph
B An egg
C A pupa C Larva
D An adult
D Pupa

2 What is the series of stages 5 What is the body part that an adult
through which a living thing grows cockroach has which a nymph
and changes? cockroach does not have?
A Larva
B Life span A Legs
C Life cycle
D Adult B Skin

C Wings

D Gills

3 Which is not true about the life 6 What is a fully grown, mature
cycle of a butterfly? insect where the female can lay
A The eggs are laid on plants. eggs?
B The pupa is the second stage.
C The larva eats a lot and is very A A larva
active.
D The adult is the last stage. B A nymph

C An adult

D A pupa

Chapter 1 3
Life Cycles

7 What is the meaning of molting? 9 Which plant part is required for
A It is the shedding of the outer the young plant to start making its
layer or covering for a new own food?
growth. A Leaves
B It is the transformation B Roots
between the immature and C Shoots
mature stages. D Flowers
C It is the breathing system of
insects. 10 What does a seed need to
D It is the production of offsprings germinate into a young plant?
by animals. I Fertilizers
II Water
8 Which of the following young III Air
animals look like their parents? IV Warmth
I Duck A I, III and IV
II Fish B II and III
III Frog C II, III and IV
IV Mosquito D III and IV
A I and IV
B I and II
C II and III
D III and IV

4 Primary 4
Hands-on Science

Subjective Questions
Answer all the questions below.
1 The diagram below shows the stages in the life cycle of a mosquito.

WX YZ

(a) Name all the four stages

W: Y:

X: Z:

(b) Arrange all the stages in the correct sequence.



(c) Name two insects that have a similar life cycle as mosquitoes.



(d) Which stage of the life cycle of a mosquito is considered harmful?



(e) (i) Where do mosquitoes lay their eggs?


(ii) How do we control the population of mosquitoes?



(iii) Why is it easier to get rid of mosquitoes at the larval stage and the
pupal stage?



Chapter 1 5
Life Cycles

2 The diagram shows the life cycle of a frog. (ii)
(i)

(iii)
.

(a) Name the stages in the life cycle of a frog in the diagram above.
(b) Suggest an animal which has a similar life cycle as the frog.

(c) What is the special characteristic of your answer in (a)(i)?

(d) Why do frogs lay eggs in water?

(e) How does the living thing in (a)(ii) breathe?

(f) How does the living thing in (a)(iii) breathe?

6 Primary 4

Hands-on Science

3 The diagram below shows four test tubes labeled A, B, C and D containing
some seeds. Test tubes A, C and D are put near a window. Test tube B is kept
in a refrigerator.

Moist Moist Cool Cooking
cotton cotton boiled oil
wool wool water
A
BC D

(a) What happens to the seeds in each test tube? Why?
(i) Test tube A


(ii) Test tube B


(iii) Test tube C


(iv) Test tube D


(b) What is the function of cooking oil in test tube D ?


(c) How do we store the seeds for a long time until further use?



Chapter 1 7
Life Cycles