Cambridge IGCSE™
COMBINED SCIENCE 0653/21
Paper 2 Multiple Choice (Extended) May/June 2025
45 minutes
You must answer on the multiple choice answer sheet.
*0461813728*
You will need: Multiple choice answer sheet
Soft clean eraser
Soft pencil (type B or HB is recommended)
INSTRUCTIONS
There are forty questions on this paper. Answer all questions.
For each question there are four possible answers A, B, C and D. Choose the one you consider correct
and record your choice in soft pencil on the multiple choice answer sheet.
Follow the instructions on the multiple choice answer sheet.
Write in soft pencil.
Write your name, centre number and candidate number on the multiple choice answer sheet in the
spaces provided unless this has been done for you.
Do not use correction fluid.
Do not write on any bar codes.
You may use a calculator.
Take the weight of 1.0 kg to be 9.8 N (acceleration of free fall = 9.8 m / s2).
INFORMATION
The total mark for this paper is 40.
Each correct answer will score one mark.
Any rough working should be done on this question paper.
The Periodic Table is printed in the question paper.
This document has 16 pages. Any blank pages are indicated.
IB25 06_0653_21/2RP
© UCLES 2025 [Turn over
, 2
1 Osmosis can be defined as the net movement of ......1...... molecules from a region of ......2......
water potential to a region of ......3...... water potential, through a partially permeable membrane.
Which words complete gaps 1, 2 and 3?
1 2 3
A sugar higher lower
B sugar lower higher
C water lower higher
D water higher lower
2 The diagrams show four root hair cells.
Each cell is surrounded by soil with the same volume of water present.
Which root hair cell absorbs water the most rapidly?
A B
soil temperature 10 °C soil temperature 10 °C
C D
soil temperature 20 °C soil temperature 20 °C
3 Which statement explains how an increase in pH affects enzyme activity?
A The active site changes shape.
B The substrate is denatured.
C There is an increase in the kinetic energy.
D The number of collisions increases.
© UCLES 2025 0653/21/M/J/25
, 3
4 What is the balanced equation for photosynthesis?
A CO2 + H2O C6H12O6 + O2
B CO2 + 6H2O 6C6H12O6 + O2
C 6CO2 + 6H2O C6H12O6 + 6O2
D 6CO2 + 12H2O 6C6H12O6 + 6O2
5 The diagram shows a transverse section through a leaf.
layer 1
layer 2
layer 3
layer 4
Which layers have cells that can produce oxygen in the presence of light?
A 1, 2, 3 and 4
B 1, 2 and 3 only
C 2 and 3 only
D 3 and 4 only
6 What is the purpose of physical digestion?
A break down food into smaller pieces
B break down insoluble food into soluble molecules
C change food so that it can be absorbed into the blood
D digest insoluble food molecules using enzymes
© UCLES 2025 0653/21/M/J/25 [Turn over
, 4
7 The diagram shows the human alimentary canal and other organs.
Which label shows where glycerol is absorbed?
A
B
C
D
8 Which row describes aerobic respiration?
nutrient molecules
produces water releases energy
broken down
A key
B = true
C = false
D
9 Which row about the anther and stigma of a wind-pollinated flower is correct?
anther stigma stigma
position position description
A inside flower inside flower smooth
B outside flower outside flower feathery
C outside flower inside flower smooth
D inside flower outside flower feathery
© UCLES 2025 0653/21/M/J/25
COMBINED SCIENCE 0653/21
Paper 2 Multiple Choice (Extended) May/June 2025
45 minutes
You must answer on the multiple choice answer sheet.
*0461813728*
You will need: Multiple choice answer sheet
Soft clean eraser
Soft pencil (type B or HB is recommended)
INSTRUCTIONS
There are forty questions on this paper. Answer all questions.
For each question there are four possible answers A, B, C and D. Choose the one you consider correct
and record your choice in soft pencil on the multiple choice answer sheet.
Follow the instructions on the multiple choice answer sheet.
Write in soft pencil.
Write your name, centre number and candidate number on the multiple choice answer sheet in the
spaces provided unless this has been done for you.
Do not use correction fluid.
Do not write on any bar codes.
You may use a calculator.
Take the weight of 1.0 kg to be 9.8 N (acceleration of free fall = 9.8 m / s2).
INFORMATION
The total mark for this paper is 40.
Each correct answer will score one mark.
Any rough working should be done on this question paper.
The Periodic Table is printed in the question paper.
This document has 16 pages. Any blank pages are indicated.
IB25 06_0653_21/2RP
© UCLES 2025 [Turn over
, 2
1 Osmosis can be defined as the net movement of ......1...... molecules from a region of ......2......
water potential to a region of ......3...... water potential, through a partially permeable membrane.
Which words complete gaps 1, 2 and 3?
1 2 3
A sugar higher lower
B sugar lower higher
C water lower higher
D water higher lower
2 The diagrams show four root hair cells.
Each cell is surrounded by soil with the same volume of water present.
Which root hair cell absorbs water the most rapidly?
A B
soil temperature 10 °C soil temperature 10 °C
C D
soil temperature 20 °C soil temperature 20 °C
3 Which statement explains how an increase in pH affects enzyme activity?
A The active site changes shape.
B The substrate is denatured.
C There is an increase in the kinetic energy.
D The number of collisions increases.
© UCLES 2025 0653/21/M/J/25
, 3
4 What is the balanced equation for photosynthesis?
A CO2 + H2O C6H12O6 + O2
B CO2 + 6H2O 6C6H12O6 + O2
C 6CO2 + 6H2O C6H12O6 + 6O2
D 6CO2 + 12H2O 6C6H12O6 + 6O2
5 The diagram shows a transverse section through a leaf.
layer 1
layer 2
layer 3
layer 4
Which layers have cells that can produce oxygen in the presence of light?
A 1, 2, 3 and 4
B 1, 2 and 3 only
C 2 and 3 only
D 3 and 4 only
6 What is the purpose of physical digestion?
A break down food into smaller pieces
B break down insoluble food into soluble molecules
C change food so that it can be absorbed into the blood
D digest insoluble food molecules using enzymes
© UCLES 2025 0653/21/M/J/25 [Turn over
, 4
7 The diagram shows the human alimentary canal and other organs.
Which label shows where glycerol is absorbed?
A
B
C
D
8 Which row describes aerobic respiration?
nutrient molecules
produces water releases energy
broken down
A key
B = true
C = false
D
9 Which row about the anther and stigma of a wind-pollinated flower is correct?
anther stigma stigma
position position description
A inside flower inside flower smooth
B outside flower outside flower feathery
C outside flower inside flower smooth
D inside flower outside flower feathery
© UCLES 2025 0653/21/M/J/25
