Focus PT3 (2020) Science

CONTENTS

FORM 1 THEME 3 Exploration of Elements in Nature

THEME 1 Scientific Methodology 5Chapter Matter 85

1Chapter Introduction to Scientific 5.1 Matter in Nature 86
Investigation 1 5.2 Three States of Matter 90
98
1.1 Science is Part of Daily Life 2 PT3 Practice 5 100

1.2 Your Science Laboratory 4 6Chapter
1.3 Physical Quantities and Their Units 7
1.4 The Use of Measuring Instruments, Accuracy, Periodic Table

Consistency, Sensitivity and Errors 9
1.5 Density 18
1.6 Steps in a Scientific Investigation 22 6.1 Classification of Elements 101
1.7 Scientific Attitudes and Values in Carrying Out 6.2 Mixtures 109
Scientific Investigation 25 6.3 Compounds 115
PT3 Practice 1 26 120
PT3 Practice 6

7Chapter Air 121

Maintenance and Continuity of 7.1 Composition of Air 122
THEME 2 Life 7.2 Combustion 126
7.3 Air Pollution 130
2Chapter Cell as the Basic Unit of Life 28 132
PT3 Practice 7

2.1 Cell – Structure, Function and Organisation 29 THEME 4 Energy and Sustainability of Life

2.2 Cellular Respiration and Photosynthesis 38 8Chapter
PT3 Practice 2 44
Light and Optics 134

3Chapter Coordination and Response 45 8.1 The Use of Mirrors 135
8.2 Properties of Light 141
3.1 Homeostasis in Living Things 46 8.3 Reflection of Light 142
PT3 Practice 3 54 8.4 Refraction of Light 144
8.5 Dispersion of Light 148
8.6 Scattering of Light 151
8.7 Addition and Subtraction of Light 153
159
PT3 Practice 8

4Chapter Reproduction 55 THEME 5 Exploration of Earth and Space

4.1 Sexual and Asexual Reproduction 56 9Chapter Earth 161
4.2 Human Reproductive System 61
4.3 The Menstrual Cycle 65 9.1 The System and Structure of the Earth 162
4.4 Fertilisation and Pregnancy 67 9.2 Composition of the Earth 166
4.5 Factors Affecting the Development of a 70 9.3 Main Processes of the Earth 168
Foetus and Baby 71 9.4 Geohazard Phenomena 170
4.6 Infertility and Contraception 74 9.5 Age of the Earth 176
4.7 Plant Reproduction 82 9.6 Earth Resources and Applied Geology 179
184
PT3 Practice 4 PT3 Practice 9

ii

FORM 2 THEME 3 Energy and Sustainability of Life

Maintenance and Continuity of 7Chapter
THEME 1 Life

1Chapter Electricity and Magnetism 274

Biodiversity 185 7.1 Electricity 275

7.2 Flow of Electric Current in Series Circuit and 284
Parallel Circuit
1.1 Diversity of Organisms 186 7.3 Magnetism 289
1.2 Classification of Organisms 189 PT3 Practice 7 295
196
PT3 Practice 1 8Chapter

2Chapter Ecosystem 198 Force and Motion 297

2.1 Energy Flow in Ecosystem 199 8.1 Force 298
2.2 Nutrient Cycle in Ecosystem 201 8.2 Effects of Force 301
2.3 Interdependence and Interaction Among 312
203 PT3 Practice 8
Organisms and between Organisms and 211
the Environment 212 9Chapter Heat 314
2.4 Role of Human in Maintaining a Balanced
Nature 9.1 Relationship between Temperature and Heat 315
9.2 Heat Flow and Thermal Equilibrium 317
PT3 Practice 2

3Chapter 9.3 Principle of Expansion and Contraction of
Matter 323
Nutrition 214 9.4 Relationship between Types of Surface of

3.1 Classes of Food 215 Object, and Heat Absorption and Emission 328
3.2 Importance of a Balanced Diet 220 PT3 Practice 9 332
3.3 Human Digestive System 223
3.4 Process of Absorption and Transportation 227 1 0Chapter Sound Waves 334
of Digested Food and Defecation 230
10.1 Characteristics of Sound Waves 335
PT3 Practice 3 10.2 Loudness and Pitch of Sound 339
10.3 Phenomena and Applications of Reflection 342
4Chapter Human Health 232 of Sound Waves 344

4.1 Infectious and Non-infectious Disease 233 PT3 Practice 10
4.2 Body Defence 236
241 THEME 4 Earth and Space Exploration
PT3 Practice 4

THEME 2 Exploration of Elements in Nature 1 1Chapter Stars and Galaxies in the
Universe 345

5Chapter 11.1 Star and Galaxies in the Universe 346
PT3 Practice 11 351
353
Water and Solution 243 1 2Chapter

5.1 Physical Characteristics of Water 244 Solar System
5.2 Solution and Rate of Solubility 252
5.3 Water Purification and Water Supply 256 12.1 Solar System 354
259 PT3 Practice 12 363
PT3 Practice 5 364
261
6Chapter Acid and Alkali 262 1 3Chapter Meteoroid, Asteroid, Comet
270
6.1 Properties of Acids and Alkali 273 13.1 Other Bodies in the Solar System; such 365
6.2 Neutralisation as Meteoroids, Asteroids and Comets 370

PT3 Practice 6 PT3 Practice 13

iii

FORM 3 THEME 3 Energy and Sustainability of Life

Maintenance and Continuity of 6Chapter
THEME 1 Life

1Chapter Electricity and Magnetism 458

Stimuli and Responses 371 6.1 Generation of Electricity 459

6.2 Transformer 464
6.3 Transmission and Distribution of Electricity 468
1.1 Human Nervous System 372 6.4 Calculate the Cost of Electricity Consumption 476
1.2 Stimuli and Responses in Human 374 PT3 Practice 6 480
1.3 Stimuli and Responses in Plant 384
1.4 Importance of Responses towards Stimuli 389 7Chapter Energy and Power 482
in Other Animals 391

PT3 Practice 1

2Chapter Respiration 394 7.1 Work, Energy and Power 483
7.2 Potential Energy and Kinetic Energy 486
2.1 Respiratory System 395 7.3 Principle of Conservation of Energy 490
2.2 Movement and Exchange of Gases in the 400 492
Human Body 402 PT3 Practice 7
2.3 Health of Human Respiratory System 405
2.4 Adaptation in Respiratory System 408 8Chapter Radioactivity 494
2.5 Gaseous Exchange in Plants 411

PT3 Practice 2

3Chapter 8.1 History of the Discovery of Radioactivity 495
8.2 Atom and Nucleus 499
Transportation 413 8.3 Ionising and Non-ionising Radiation 500

8.4 The Use of Radioactive Rays Radiation 506
PT3 Practice 8 509
3.1 Transport System in Organisms 414
3.2 Blood Circulatory System 414
3.3 Human Blood 420
3.4 Transport System in Plants 423
3.5 Blood Circulatory System in Animals and
Transport System in Plants 431 THEME 4 Earth and Space Exploration

PT3 Practice 3 432 9Chapter

THEME 2 Exploration of Elements in Nature Space Weather 511

4Chapter 9.1 The Sun’s Activities that Affect the Earth 512
9.2 Space Weather 517
PT3 Practice 9 519
Reactivity of Metals 434

4.1 Variety of Minerals 435 1 0Chapter Space Exploration 521
4.2 Reactivity Series of Metals 438
4.3 Extraction of Metals from Its Ore 443 10.1 Development in Astronomy 522
447
PT3 Practice 4

5Chapter 10.2 Development and Technology in Space
Exploration 523
PT3 Practice 10 529
Thermochemistry 449

5.1 Endothermic and Exothermic Reactions 450 Answers 531
PT3 Practice 5 456

iv

2Chapter Theme 2: Maintenance and Continuity of Life
Form 1

Pengenalan kepada
PCeenlyl iaassathtaenBSaasiinctUifnikit of Life

Made up of many cells Multicellular organisms Systems

Unicellular organisms form Cells form Tissues Organs
Made up of single cell
are

Basic unit of life

Animal cell similarities Plant cell
have
has chloroplasts and
a large vacuole

occurs in Nucleus, cell membrane, occurs in chloroplasts
mitochondria cytoplasm and mitochondria Photosynthesis

Cellular respiration

Produces energy by Makes food from carbon dioxide
breaking down food. and water in the presence of
chlorophyll and sunlight.
28

2.1 Cell – Structure, Function and   Science PT3  Chapter 2  Cell as the Basic Unit of Life 
Organisation
5. When a cell divides rapidly without control,
it can form a tumour or cancer.

What is a Cell? Form
Form

A cell is the basic unit that makes up all Normal Cell division 1
living things. cell Cancer cell

1. Cells are too small that they cannot be seen

with the naked eye; they can only be clearly
seen under a microscope.



Cell size and scale Normal cell division
stops
INFO

SCIENCE IINNFFOO Uncontrolled continuous
cancer cell division
An English scientist, Robert Hooke was the
first person to discover cells. He was observing Figure 2.2 Normal cell and cancer cell division
a slice of cork under a simple microscope
made by him when he found the cork consisted 6. If not destroyed, cancer cells will divide
of an arrangement of small units which were uncontrollably to form a tumour, an
separated by walls. He named these small units abnormal lump of cells.
as cells, which means small rooms in Latin.
Formation of tumour
What is a cell? What is done by a cell?

2. Cells carry out life processes like respiration, Cancer cell Normal cell
growth, reproduction and excretion. division

3. Cells also undergo cell division, a process by Figure 2.3 The formation of tumour
which a single cell divides into two or more
cells. 7. Tumours can destroy surrounding cells.

Figure 2.1 Cell division 8. A tumour can invade surrounding cells and
spread from one part of the body to another
4. Cell division is essential for the growth of which then leads to the malfunctions of the
living things and in producing new cells to body parts. This is called cancer.
replace damaged or dead cells.

29

  Science PT3  Chapter 2  Cell as the Basic Unit of Life

Structures of Animal Cell and Plant Cell

1. Cells are very tiny and can only be clearly seen under a microscope.

Form
Form
2. A microscope is used to observe the structures of animal and plant cells in Activities 2.1 and 2.2.

1 Eyepiece magnifies the image of the specimen Steps
to about ten times (10x) magnification.
1 Place the microscope in
Tube connects the eyepiece to the objective a bright place.
lenses.
2 Crank the low power
Coarse focus knob is used to move the objective lens down so
low power objective lens. that it is clicked into
position.
Fine focus knob is used to move the
high power objective lens to bring the
specimen into better focus.

Low power objective lens 3 Adjust the diaphragm
magnifies the image of the and mirror so that there
specimen to 4x. is sufficient light to view
the specimen through
Medium power objective the microscope.
lens magnifies the image
of the specimen to 10x. 4 Place the slide on the
stage and use the clips
High power to hold the slide.
objective lens
magnifies the image 5 Turn the coarse focus
of the specimen to knob to lower the body
40x. tube as close to the
specimen as possible
Diaphragm controls without touching it.
the amount of
light reaching the
specimen.

Mirror reflects 6 Look through the
light towards eyepiece, and turn
the diaphragm. the coarse focus knob
anticlockwise to move
Stage is the the body tube up until
platform to place the the image comes into
slides. focus.

Clips hold the slides 7 Turn the fine focus
in place. knob for fine focusing.

Figure 2.4 The structure of a microscope and the way to use it

30

  Science PT3  Chapter 2  Cell as the Basic Unit of Life 

EkAscpteivriimtye2n.12.1

Aim: To prepare an animal cell slide and to examine animal cells Form
(human cheek cells). Form
Materials and apparatus: Methylene blue solution, distilled water,
toothpick, filter papers, glass slide, cover slip, light microscope, dropper, 1
mounting needle and forceps.
Procedure: Distilled Toothpick
1. A drop of distilled water is placed on the centre of a clean slide. water
2. The blunt end of a toothpick is used to gently scrape the inner Cheek Mounting
scrapings needle
lining of the cheek.
3. The scrapings are placed in the middle of the water drop on the Cover slip

slide.
4. A cover slip is lowered slowly on the specimen using a mounting

needle to ensure that air bubbles are not trapped under the cover
slip.
5. A drop of methylene blue solution is placed on one edge of the
cover slip and a piece of filter paper is placed on the other edge of
the cover slip. The filter paper will draw the methylene blue solution
across the slide to stain the cells.
6. Excess methylene solution is absorbed using another piece of filter
paper.
7. The slide is observed under the low power objective lens of the
light microscope, followed by the high power objective lens.
8. The structure of the cheek cells is drawn and labelled accordingly.

Observations: Methylene Filter
blue solution paper

Cytoplasm Figure 2.5 Preparing the slide of
human cheek cells

Cell membrane TIMSS Challenge 1
Nucleus
Why do we need to add a drop of
Figure 2.6 Human cheek cells methylene blue solution onto the
cheek cells when preparing the
slide of cheek cells?

Discussions: Common Error

1. Methylene blue solution stains the cheek cell, so that the All living things
structure of the cell can be seen clearly. contain cells.

2. Human cheek cells do not have a fixed shape. All living things are
3. The structures of the human cheek cells as seen under the light made up of cells.

microscope are the nucleus, cell membrane and cytoplasm.

Conclusion:
An animal cell does not have a fixed shape, and has a nucleus, cell membrane and cytoplasm.

31

  Science PT3  Chapter 2  Cell as the Basic Unit of Life

EkAscpteivriimtye2n.2.1Form Onion
Form scale
Aim: To prepare a plant cell slide and to examine plant cells (epidermal Epidermal layer of onion
cells of an onion bulb)
Epidermal layer
Materials and apparatus: Onion bulb, iodine solution, distilled water, of onion

1 filter papers, glass slide, cover slip, light microscope, dropper, mounting Mounting
needle, scalpel and forceps. needle
Cover slip
Procedure:
1. A drop of distilled water is placed on the centre of a clean slide.
2. An onion scale is cut using a scalpel and an epidermal layer from it

is peeled off using a forceps.
3. The epidermal layer is then placed in the middle of the water drop on

the slide.
4. A cover slip is lowered slowly on the specimen using a mounting needle

to ensure that air bubbles are not trapped under the cover slip.
5. A drop of iodine solution is placed on one edge of the cover slip and

a filter paper is held at the other edge of the cover slip to draw the
iodine solution across the slide to stain the cells.
6. Excess iodine solution is absorbed using another piece of filter paper.
7. The slide is observed under the low power objective lens of the light
microscope, followed by the high power objective lens.
8. The structure of the epidermal cells is drawn and labelled
accordingly.

Observations: Figure 2.7 Preparing the
slide of epidermal cells
Membrane cell
Cell wall Tips

Nucleus Methylene blue solution is
Cytoplasm usually used to stain animal
Vacuole cells, while iodine solution is
used to stain plant cells.

Figure 2.8 Epidermal cells of an onion bulb

Discussion: TIMSS Challenge 2

1. Iodine solution stains the nucleus brown so that the structure of Name two structures that are
epidermal cells can be seen clearly.
found in plant cells but not in
2. Epidermal cells of onion bulb have a fixed shape.
3. The structures of the epidermal cells as seen under the light animal cells. PAK-21

microscope are the cell wall, cell membrane, nucleus, cytoplasm
and vacuole.
4. Onion cells do not contain chloroplasts.

Conclusion:
A plant cell has a fixed shape, a nucleus, cell membrane, cytoplasm, cell wall and vacuole.

32

  Science PT3  Chapter 2  Cell as the Basic Unit of Life 

Functions of Structures in Animal Cells and Common Error
Plant Cells

1. There are many similarities and differences between Form
animal cells and plant cells. Form
All plant cells contain chloroplasts.
2. Both cells have a nucleus, cytoplasm, cell membrane Not all plant cells have 1
and mitochondria.
chloroplasts. For example, the
3. Plant cells have a cell wall, chloroplasts and vacuole. epidermal cells of an onion
bulb which do not carry out
photosynthesis do not contain
chloroplasts.

4. The structures of cells have different functions.

Cell membrane
• A thin layer which forms the external boundary of the cell.
• Controls the movement of materials into and out of the cell.

Nucleus
• Oval or spherical in shape.
• Controls all the activities of the cell.
• Contains chromosomes that are made up of deoxyribonucleic acid (DNA) which

carries genetic information that determines the characteristics of an organism.

Cytoplasm
• A jelly-like substance.
• As a medium where chemical processes occur.

Mitochondrion
• Cylindrical-shaped.
• The site of cellular respiration to generate energy.

The difference Animal cell
between animal
Plant cell
VIDEO and plant cells

Vacuole Cell wall Chloroplast
• A fluid-filled sac containing • An outer layer which
• Contains a green
cell sap. surrounds the cell pigment called
• Absorbs water and keeps membrane of a plant cell. chlorophyll that
• Provides support and helps absorbs sunlight
the cell turgid. This turgidity protect the cell, and gives for the process of
provides support to the cell. a fixed shape to the cell. photosynthesis in
green plants.

Figure 2.9 Functions of animal and plant cell structures

33

  Science PT3  Chapter 2  Cell as the Basic Unit of Life

Comparison between Animal Cells and Plant Cells

Form Animal cell Plant cell
Form
Similarities Icon Focus KSSM Science form 1 English ver.

Both have a nucleus, cell membrane, cytoplasm and mitochondria

1 Differences Has a cell wall made of cellulose
Cell wall Has chloroplasts that containPcluhrlaolrophyll
Does not have a cell wall
Does not have chloroplast Chloroplast Has one or a few large vacuoles
Usually absent, but if present, the vacuoles
Vacuole Has a fixed shape
are small and scattered
Does not have a fixed shape Shape

Figure 2.10 Similarities and differences between animal cells and plant cells

Unicellular and Multicellular Organisms Singular PPlluurraall
Mitochondrion Mitochondria
Unicellular organisms
Multicellular organisms

Unicellular organisms are organisms that Multicellular organisms are organisms that
consist of only one cell. consist of more than one cell.

• Although consisting of only one cell, unicellular • Humans, animals and plants are examples of

organisms are able to perform all living processes multicellular organisms.

within a single cell - they can move, feed, reproduce, • Multicellular organisms are made up of many
grow, respond to stimuli, excrete and respire. types of cells which differ in terms of structure and

• Unicellular organisms are also known as function.

microorganisms because of their tiny size and can • Some multicellular organisms are microorganisms

only be seen under a microscope. that are very tiny and cannot be seen clearly by the
naked eye.
• Amoeba and Paramecium are unicellular
animals, whereas yeast and Chlamydomonas are

unicellular plants.

• Euglena can be classified as a plant because it can

make its own food in the presence of sunlight.

• Euglena can also be classified as an animal
because it can feed and move by using flagella.

Hydra Spirogyra Mucor

Figure 2.12 Multicellular microorganisms

Paramecium Chlamydomonas • Most multicellular organisms are bigger in size and
complex compared to unicellular organisms.
Euglena Amoeba
• Mammals, reptiles, amphibians, birds and fish are
examples of multicellular animals.

• Algae, ferns and most of the flowering plants are
examples of multicellular plants.

Figure 2.11 Unicellular organisms

34

  Science PT3  Chapter 2  Cell as the Basic Unit of Life 

The Types and Functions of Animal Cells and Plant Cells

1. Humans, animals and plants are multicellular organisms in SCIENCE IINNFFOO Form
large size, and they are made up of different types of cells for Form
various life processes. Humans are made up of
more than 50 trillion 1
2. These cells have different shapes and structures to carry out (50 000 000 000 000) cells.
different functions. They are called specialised cells.

Specialised cells are cells that have become differentiated to carry out a particular function.

3. Figures 2.13 and 2.14 show various types of specialised cells in humans and plants with their
special features and functions.

Nerve cells Epithelial cells
• Also known as neurons.
• Have long, thin fibres. • Epithelial cells that Cilia
• Carry information in the form line the trachea

of nerve impulses to different (respiratory tract)
parts of the body.
have a thin layer of
Red blood cells
• Have biconcave disc tiny moving ‘hairs’

shape which provides called cilia.
a large surface area.
• Contain no nucleus. • Cover the outer surface of the
• Contain haemoglobins (red
pigments) which combine with body and line the surfaces of
oxygen.
• Transport oxygen from the lungs organs.
to the whole body, and transport
carbon dioxide from the body cells White blood cells
back to the lungs which is then • Do not have a fixed
expelled during exhalation.
shape.
Muscle cells • Destroy bacteria that
• Muscle cells along
enter the body and
the wall of intestine protect the body against
(digestive system) are diseases.
elongated cells, whereas
muscle cells in the heart Reproductive cells
(cardiac muscle) have a • Sperm cell is the male
branched shape.
• Muscle cells contract reproductive cell that has a
and relax to produce long tail which allows it to swim
movements of various towards the egg cell (ovum),
body parts. the female reproductive cell.
• Sperm contains genetic
information from the father,
whereas ovum contains genetic
information from the mother.

Sperm Ovum
Figure 2.13 Various types of specialised cells in humans and their functions

35

  Science PT3  Chapter 2  Cell as the Basic Unit of Life

Epidermal cells Cuticle layer Palisade cells
• Epidermal cells are flat and
• Contain lots of Cell wall
have a large vacuole. chloroplasts which Chloroplast
Form contain chlorophyll.
Form Vacuole
• Coated by a waxy cuticle layer • Absorb sunlight to Cytoplasm
carry out photosynthesis. Nucleus
on top, this reduces water loss.

• Epidermal cells are transparent

1 to allow light to penetrate the
cell for photosynthesis.

Plant cells

Root hair cells Guard cells A pair of guard cells

• Have a long thin extension, Root hair • Kidney-shaped cells. Chloroplast
the root hair which provides • Two guard cells surround Stoma
a large surface area for an opening called stoma.
absorption of water and • Guard cells help to regulate
nutrients from the soil. gas exchange by opening
and closing the stoma.

Figure 2.14 Various types of specialised cells in plants and their functions

Formation of an Organism

1. Cells in multicellular organisms are 4. Several specialised organs work together
organised to form tissues, organs and to form a system which performs a major
systems which all together form an function.
organism.
5. All the systems combine to make up what
2. Cells of the same structure that carry out a is known as a multicellular organism.
similar function make up a tissue.

3. A group of different tissues that work
together to perform a particular function
forms an organ.

HPOraTkStisCFhoramllaetnifg1e 1 Human

• Evaluating Multicellular
Is blood a cell or a tissue? Why? organism

Epithelial tissue Stomach Digestive system All the systems
combine to form
Tissue Organ System
A group of Two or more Several organs a multicellular
specialised cells types of tissues work together to organism.
with a similar work together to perform a major
function. perform a particular
function.
function.
Epithelial cell
Figure 2.15 Cell organisation in a
Cell multicellular organism
Basic unit of life.

36

  Science PT3  Chapter 2  Cell as the Basic Unit of Life 

Systems in the Human Body
1. There are various systems in the human body that work together to carry out different

functions.
2. All these systems are coordinated to form a complete life.
Form
Blood circulatory Respiratory system Digestive system Form
system Excretory system
Nose Mouth 1
Heart Trachea Oesophagus Lung
Blood Lung Liver Kidney
vessels Stomach Ureter
Small intestine
Large intestine Urinary
bladder
Transports respiratory Absorbs oxygen and Breaks down complex
gases, nutrients, releases carbon dioxide. food into smaller form so Skin
that the nutrients can be
hormones and waste Muscular system easily absorbed into the Removes excretory
products. products such as urea
body. and uric acid from the
Integumentary system
Skeletal system body.
Skin
Skull Lymphatic system

Muscles Thymus gland
Lymph
Bone
Lymph node
Lymphatic
vessels

Made up of human Assists humans in Provides support to Defends the body
skin that protects the movement. the body and protects against infections.
body from infection and internal organs such as
keeps the body from Endocrine system
losing water excessively lungs and brain.
Pituitary gland
(dehydration). Thyroid gland Reproductive system
Adrenal gland
Nervous system Pancreas Uterus
Ovary (female) Vagina
Brain Testis (male) Ovary

Spinal cord

Nerves

Testis
Penis

Carries information in the Secretes hormones to Produces sperm cells, ova and hormones to produce
form of nerve impulses coordinate the body offspring.
and coordinates all the activities together with
body activities. the nervous system.

37

  Science PT3  Chapter 2  Cell as the Basic Unit of Life 2.2 Cellular Respiration and
Photosynthesis
Appreciating the Existence of
Various OrganismsForm Respiration can be divided into two stages:
Form (a) External respiration or breathing
1. We should appreciate the existence of wide (b) Internal respiration or cellular respiration
variety of organisms on Earth as a sign of
the glory of God. External respiration (breathing) is the
exchange of oxygen and carbon dioxide
1 2. Various organisms live together, interact and
depend on one another for their survival. between an organism and its environment.

3. Organisms also interact with the
environment to create a balanced
ecosystem.

Formative Practice 2.1 Cellular Respiration

1. Arrange the steps in preparing a plant cell slide 1. We require energy to carry out various
in the correct sequence. activities and living processes.

( ) The slide is observed under the 2. The energy is obtained from the food we
microscope. take.

( ) A thin epidermal layer is peeled off from 3. Our body cells are able to break down the
the onion. food to release energy stored in it. This is
called cellular respiration.
( ) The specimen is covered with a cover
slip using a mounting needle. Internal respiration (cellular respiration)
is the oxidation and breakdown of glucose
( ) A drop of iodine solution is added to the that occur in the living cells to release
slide to stain the structures of the cell. energy.

( ) The epidermal layer is placed on a slide
in a drop of water.

2. Match the human cells to their functions.
Nerve cells ► ◄ Involved in reproduction

Sperm cells ► ◄ Allow body movement 4. Cellular respiration uses oxygen we breathe
Muscle cells► ◄ Transport oxygen in and glucose from the food to release
energy.
Red blood ► ◄ Receive and send nerve
cells impulses 5. Carbon dioxide and water are formed as
by-products during cellular respiration.
3. State three differences between animal cells
and plant cells. 6. Cellular respiration can be defined as the
process that needs oxygen and glucose to
4. What is meant by unicellular organism and release energy, carbon dioxide and water.
multicellular organism?

HPOraTkStisCFhoramllaetnifg1e 2 C6H12O6 + 6O2 → 6CO2 + 6H2O + 2898 kJ

• Evaluating Glucose Oxygen Carbon Water Energy
dioxide

Predict what would happen to the number of

white blood cells produced if we are attacked

by flu. State the inference for your prediction.

38

  Science PT3  Chapter 2  Cell as the Basic Unit of Life 

Photosynthesis Leaf Boiling FormEthanol
water Form Hot water
1. Green plants are able to make their own
food through the process of photosynthesis. A leaf is immersed Bunsen burner 1
into a beaker of (turned off)
Photosynthesis is the process by which boiling water for a
green plants make food from carbon few minutes to break The leaf is placed
dioxide and water in the presence of light down the cell walls into a boiling
and chlorophyll. and soften the leaf. tube containing
ethanol which is
2. Chloroplasts are the cell structures involved then placed into a
in photosynthesis and contain chlorophyll beaker of hot water
that absorbs sunlight. for a few minutes
to decolourise the
3. Green plants use carbon dioxide and leaf (to remove
water in the presence of sunlight and chlorophyll).
chlorophyll to make food in the form of
glucose. Oxygen is released as the by-
product of photosynthesis.

Sunlight Carbon dioxide Hot Iodine
is absorbed water solution
Chlorophyll
Glucose The decolourised Wtilehite
produced leaf is then dipped
into a beaker of The leaf is placed
Oxygen released hot water for a few on a white tile. A
seconds to get the few drops of iodine
ethanol off the leaf. solution are added
on to the leaf to test
Water absorbed for starch.
by roots

Figure 2.16 The process of photosynthesis Figure 2.17 Steps involved in the iodine test for starch

4. The whole process of photosynthesis can be 7. The presence of starch in the leaf can be
summarised by the following equation: tested using iodine solution after removing
the chlorophyll using an alcohol.
6H2O + 6CO2 Sunlight C6H12O6 + 6O2
Water Carbon Chlorophyll Glucose Oxygen 8. Starch is present if the brown colour of
iodine solution turns blue-black.
dioxide
9. Experiments 2.1 – 2.4 are carried out to
5. Excess glucose is stored in the form of show the factors required for photosynthesis
starch in leaves, stems, fruits and roots. such as light, carbon dioxide, chlorophyll
and water.
6. We can determine whether photosynthesis
has taken place in a plant by testing the
presence of starch in the leaf using the
iodine test.

39

  Science PT3  Chapter 2  Cell as the Basic Unit of Life

Ekxsppeerirmimeennt 2.1

Problem statement: Does photosynthesis require sunlight?Form
Hypothesis: Sunlight is essential for photosynthesis.Form
Aim: To investigate whether sunlight is essential for photosynthesis.
Plant K
1 Manipulated variable: Presence of sunlight (In the dark)
Responding variable: Colour change of iodine on the leaf
Constant variable: Type of plants Plant L
Materials and apparatus: Two similar potted green plants, boiling tube, beaker, Figure 2.18
Bunsen burner, tripod stand, wire gauze, forceps, dropper, white tile, ethanol, iodine
solution and hot water.
Procedure:
1. Two similar potted plants are prepared and labelled as plant K and plant L.
2. Plant K is exposed to sunlight whereas plant L is kept in the dark.
3. After one week, a leaf is plucked from each plant and then tested for the presence
of starch.

Observations:

Leaf Presence of Observation for Inference
Plant K sunlight the test for starch
Plant L Yes Photosynthesis takes place in the presence of
The leaf turns sunlight.
No blue-black Photosynthesis does not take place in the dark
(absence of sunlight).
No change

Discussion:

1. Starch is present in the leaf of plant K that is exposed to the sunlight whereas starch is absent in the leaf
of plant L that is not exposed to the sunlight.

2. Plant L does not receive sunlight, therefore photosynthesis does not take place.

Conclusion:
The hypothesis is accepted. Sunlight is essential for photosynthesis.

Ekxsppeerirmimeennt 2.12

Problem statement: Does photosynthesis require carbon dioxide?
Hypothesis: Carbon dioxide is essential for photosynthesis.
Aim: To investigate whether carbon dioxide is essential for photosynthesis.
Manipulated variable: Presence of carbon dioxide
Responding variable: Colour change of iodine on the leaf
Constant variable: Type of plants
Materials and apparatus: Two similar potted green plants, bell jars, glass plates coated with vaseline, beaker,
boiling tube, white tile, Bunsen burner, tripod stand, wire gauze, forceps, dropper, ethanol, hot water, iodine
solution and potassium hydroxide solution.
Procedure:
1. Two potted plants are kept in a dark place for two days to remove the starch.
2. The apparatus is set up as shown in Figure 2.19 and kept under the Sun.

40

Sunlight   Science PT3  Chapter 2  Cell as the Basic Unit of Life 
Sunlight

Air without Air Form
carbon dioxide Form
Bell jar

1

Potassium hydroxide solution

Green plant M Glass plates with vaseline Green plant N

Figure 2.19 The set-up of apparatus

3. After a few days, the leaves from both plants are tested for the presence of starch.

Observations:

Leaf Presence of Observation for the Inference
Plant M carbon dioxide test for starch
Plant N Photosynthesis does not take place in the
No No change absence of carbon dioxide.
Photosynthesis takes place in the presence of
Yes The leaf turns carbon dioxide.
blue-black

Discussion:

1. No starch is formed in the leaf of plant M which is exposed to the air without carbon dioxide.
2. Potassium hydroxide solution absorbs carbon dioxide inside the bell jar.
Conclusion:

The hypothesis is accepted. Carbon dioxide is essential for photosynthesis.

Ekxsppeerirmimeennt 2.31

Problem statement: Does photosynthesis require chlorophyll? Figure 2.20 Variegated leaves
Hypothesis: Chlorophyll is essential for photosynthesis.
Aim: To investigate whether chlorophyll is essential for photosynthesis.
Manipulated variable: Presence of chlorophyll
Responding variable: Colour change of iodine on the leaf
Constant variable: Type of plants
Materials and apparatus: A variegated leaf, beaker, boiling tube, white
tile, Bunsen burner, tripod stand, wire gauze, forceps, dropper, ethanol, hot
water and iodine solution.
Procedure:
1. A variegated leaf is plucked from a plant which has been exposed to

the sunlight for several hours.
2. A sketch to show the green and non-green colour distributions on the

leaf is drawn.
3. The leaf is tested for the presence of starch.
4. The observations are recorded.

41

  Science PT3  Chapter 2  Cell as the Basic Unit of Life

Observations:

Green Blue-black
region (starch present)

Form White Brown
Form region (starch absent)

Figure 2.21 Sketches of the variegated leaf before and after the test for starch

1 Discussion:

1. A variegated leaf is a leaf with different colours (pigments) on it.

2. Starch is present only in the green region of the leaf that contains chlorophyll.

3. No starch is formed in the non-green region of the leaf due to the absence of chlorophyll.

Conclusion:
The hypothesis is accepted. Chlorophyll is essential for photosynthesis.

Ekxsppeerirmimeennt 2.41

Problem statement: Does photosynthesis require water? Plant P Plant Q
Hypothesis: Water is essential for photosynthesis.
Aim: To investigate whether water is essential for photosynthesis. Figure 2.22 The set-up of
Manipulated variable: Presence of water apparatus
Responding variable: Colour change of iodine on the leaf
Constant variable: Type of plants
Materials and apparatus: Two similar potted green plants, water,
boiling tube, white tile, Bunsen burner, tripod stand, wire gauze, forceps,
dropper, ethanol, hot water and iodine solution.

Procedure:
1. Two similar potted green plants are exposed to sunlight.
2. Plant P is watered every day whereas plant Q is not watered.
3. After one week, a leaf is plucked from each plant and then tested for the presence of starch.

Observations:

Leaf Presence of Observation for the Inference
Plant P water test for starch
Plant Q Yes The leaf turns Photosynthesis takes place in the presence of
blue-black water.
No Photosynthesis does not take place in the
No change absence of water.

Discussion:
Starch is present in the leaf of plant P that is watered every day whereas starch is absent in the leaf of plant Q
that is not watered.

Conclusion:
The hypothesis is accepted. Water is essential for photosynthesis.

42

  Science PT3  Chapter 2  Cell as the Basic Unit of Life 

The Differences between Cellular Respiration and Photosynthesis

1. Cellular respiration and Form
photosynthesis are opposite Form
processes that complement each
other in the environment.

2. Photosynthesis by green plants Light energy Photosynthesis occurs 1
produces food (glucose) for other absorbed in the chloroplast of
organisms and releases oxygen
into the atmosphere. Glucose plant cells
+
3. The oxygen and glucose produced Chloroplast Carbon dioxide
are used by other organisms for Oxygen +
cellular respiration to obtain
energy. Water

4. Cellular respiration releases carbon
dioxide which is used by green
plants to carry out photosynthesis,
and this cycle continues.

5. Therefore, both processes of Mitochondrion Cellular respiration occurs
photosynthesis and cellular Energy is released ATP in the mitochondrion of
respiration are important and
complement each other for living cells of all organisms

(a) the survival of living things. Figure 2.23 Relationship between photosynthesis and
cellular respiration
(b) maintaining the balance of
oxygen and carbon dioxide in
the atmosphere.

Table 2.1 Differences between cellular respiration and Formative Practice 2.2
photosynthesis

Cellular respiration Photosynthesis 1. Why do we test for the presence
of starch to determine if
Occurs in all the living cells. Occurs in all the plant cells photosynthesis has occurred?
that contain chlorophyll.
2. Based on the diagram below,
Process of breaking down Process of making food answer the following questions.
food (glucose). (glucose). (a) What are processes X and Y?
(b) What are the purposes of
Takes place in mitochondria. Takes place in chloroplasts. processes X and Y?
(c) Which process also occurs in
animal cells?

Carbon dioxide and water are Carbon dioxide and water Carbon dioxide Process X
released. are used. Oxygen (day)

Oxygen is used. Oxygen is released. Light

Carbohydrates
Water

Occurs all the time (day and Occurs only in the presence Energy

night). of light. Oxygen Process Y

Energy is released during the Light energy is absorbed to Water Carbon dioxide (day and night)

breakdown of food. make food.

43

  Science PT3  Chapter 2  Cell as the Basic Unit of Life 2

PT3 Practice

Form
Form
SECTION A
A Glucose + Oxygen → Carbon dioxide + Water
1 1. The following statement describes the + Energy
characteristics of cell P.
B Water + Carbon dioxide → Glucose + Oxygen
•  No cell wall + Energy
•  No nucleus
C Oxygen + Water → Carbon dioxide + Glucose
Which of the following is cell P? + Energy
A Nerve cell
B Palisade cell D Energy + Oxygen → Glucose + Carbon dioxide
C Red blood cell
D Onion epidermis cell 3. Which of the following is the importance of
photosynthesis and cellular respiration process?
2. Cellular respiration is the energy generating A To preserve the balance of oxygen and carbon
process. Which of the following is the correct dioxide content in the atmosphere.
word equation for the cellular respiration process? B To preserve the balance of nitrogen in the
atmosphere.
C To maintain the cleanliness of the environment.
D To avoid the increase in global temperature.

SECTION B

1. (a) Diagram below shows two types of cells. Name the cells.
(i) (ii)

(b) Underline the correct statements regarding the photosynthesis. [2 marks]
(i) Carbon dioxide and water are (used / produced) in the process of photosynthesis. [2 marks]
(ii) Light energy is (absorbed / released) to synthesise food molecules.

SECTION C

1. Teacher Ali showed a video about the process of photosynthesis and its importance to the students in class
1 Arif. The following statement is one of the quotes in the video:

Photosynthesis is the food-making process by green plants from water and carbon dioxide with the
presence of light and chlorophyll.

(a) State the word equation for the process of photosynthesis. [3 marks]

(b) Carbon dioxide is a substance that is required in the process of photosynthesis. [1 mark]
From where do plants get this supply of carbon dioxide? [2 marks]
(c) State two importance of the process of photosynthesis. [2 marks]
(d) State how deforestation interrupts the process of photosynthesis.

44

Form 1 of a ream of paper is divided by 450. In SECTION B Form
this way, the mass of 1 sheet of paper Form
1Chapter Introduction to Scientific is estimated. 1. (a) (i) Beaker
Investigation (ii) Filter funnel
Daily Application (b) (i) Measures the time
(ii) Measures the length 1
Air conditioner is best placed at the top of
Formative Practice 1.1 the wall of a room because it produces cold SECTION C
air. The cold air which is denser than warm
1. A natural phenomenon is an observable air will go down in the room and replace the 1. (a) (i) Measuring cylinder
event which is not man-made. warm air. At the same time, the less dense
warm air goes up and the room is cooled (ii) To determine the volume of liquids
2. • Invention of telephone allows people very quickly.
to communicate at a distance. (iii) 22.0 cm3

• Invention of Internet allows people to (iv) Burette, pipette
search and access a vast amount of
information from home. (v) Water displacement method
Mass
3. Doctor, forensic scientist, botanist (b) (i) Density = Volume
(Accept other reasonable answers)
HPOraTkStisCFhoramllaetnifg1e 1 (ii) The density of gold = 20
1

= 20 g cm-3

The densitiy of pure water is 1 g cm-3 and the The density of glass = 2
volume of water given is 73.6 cm3. 1
Formative Practice 1.2 Mass of water
= Density of water x Volume of water = 2 g cm-3
1. The bottle contains chemical that = 1 x 73.6
catches fire easily / flammable. = 73.6 g (ii) Gold is denser than glass

2. A fire may occur. (iv) The mass of gold is higher than
3. Get out as quickly and safely as
that of glass.
possible from the fire to a safer place.
When water turns into ice, its mass remains 2Chapter Cell as the Basic Unit of
Formative Practice 1.3 unchanged. Therefore, 73.6 cm3 of water will Life
freeze to form 73.6 g of ice.

Mass of water = Mass of ice = 73.6 g.

1. Physical S.I. unit Symbol of As given, the density of ice = 0.92 g cm-3. TIMSS Challenge 1
quantity S.I unit Hence, the volume of ice can be calculated:
Methylene blue solution is used to colour
Volume of ice = __M_a_s_s__o_f _ic_e__ (dye) the cheek cell so that the structure can
Density of ice be seen clearly under a microscope.

Mass kilogram kg _7_3_._6_g_ TIMSS Challenge 2
0.92 g cm-3
Time second s =
K
= 80 cm3

Temperature Kelvin

Formative Practice 1.5 Chloroplast and cell wall

2. (a) 1 200 m 1. Density of water HPOraTkStisCFhoramllaetnifg1e 1
(b) 10.08 m
(c) 0.57 m = _1__0_0_0_k_g_ ___1__0_0_0_g___
1 m3 1 000 000 cm3
x Blood is not a cell but a connective tissue
because it contains different cells (red blood
Formative Practice 1.4 = 1 g cm-3 cells, white blood cells, plasma and platelets)
that work together to achieve a specific
1. Measuring tape Hence, 1 cm3 of water has a mass of 1 g. function in our body.

2. A clinical thermometer is more accurate 2. (a) Egg is denser than water. Formative Practice 2.1
than a laboratory thermometer because (b) The egg will float on the water.
clinical thermometer can measure (c) Ice floats on the ocean water. 1. 5 → 1 → 3 → 4 → 2
temperature accurately up to 0.1°C,
whereas laboratory thermometer can Formative Practice 1.6 2. Nerve cells – Receive and send nerve
measure with the accuracy of only 1°C. impulse
Make a new hypothesis and carry out an
3. (a) Vernier calipers experiment to test the hypthothesis. Sperm cells – Involved in reproduction
(b) 2.53 cm
(c) To obtain a more accurate reading, Muscle cells – Allow body movement
zero error has to be taken into
consideration. Red blood cells – Transport oxygen

(d) • If the zero error is a positive zero Formative Practice 1.7 3. The differences between an animal cell
error, the actual reading should and plant cell are as below.
be 2.53 – 0.04 = 2.49 cm. No. Aishah should be honest while recording
and validating data. Animal cell Plant cell
• If the zero error is a negative
zero error, the actual reading
should be = 2.53 – (-0.04) No cell wall Has cell wall

= 2.57 cm PT3 Practice 1 No chloroplast Has chloroplast

4. Weigh the mass of a ream of A4 paper SECTION A 4. C No fixed shape Has fixed shape
(450 sheets of paper). Then, the mass 1. B 2. A 3. C

531

  Science PT3  Answers

4. Unicellular organisms are organisms HPOraTkStisCFhoramllaetnifg1e 2 HPOraTkStisCFhoramllaetnifg1e 3
that consist of only one cell while

multicellular organisms are organisms

that consist of more than one cell. Reptiles and amphibians are found less Yellowish and concentrated urine is a sign of

Form in the Arctic because of the extreme cold dehydration. Be sure to drink enough water to
Form
HPOraTkStisCFhoramllaetnifg1e 2 temperatures in the Arctic. Reptiles and maintain very light-coloured urine.
amphibians are unable to maintain their body

1 The number of white blood cells produced will temperature. The body temperature of reptiles PT3 Practice
increase to fight or destroy the pathogen that SECTION A
enters our body. and amphibians will change according to the 3
external environment. When the temperature
is too low, their body temperature will also

Formative Practice 2.2 decrease. This will affect their body function 1. A 2. C 3. D
and can lead to death. Therefore, reptiles and
amphibians are difficult to survive in the Arctic. SECTION B

1. The food (glucose) made by the plants Daily Application 1. (a) (i) Stoma
is kept in the form of starch. Therefore, (ii) Guard cells
one of the ways to test if photosynthesis Emergency treatments that can be done if a (b) (i) guard cells
has occurred is to test for the presence friend is attacked by a heatstroke: (ii) increase
of starch. • Fan the friend while wetting his or her
SECTION C
2. (a) X: Photosynthesis skin with water.
Y: Cellular respiration • Apply ice packs on the friend’s armpits, 1. (a) (i) Homeostasis
(ii) While jogging, more oxygen is
(b) X: To make food / glucose groin, neck, and back.
Y: To produce energy • Provide cool drinks or isotonic drinks to needed for cellular respiration.
Therefore, the heart need to
(c) Process Y the friend. pump more blood to cells in
• Loosen the friend's clothing. the body. Thus, the rate of
PT3 Practice 2 Heatstroke prevention: heartbeat will increase.
• Drink more water. (b) Cause: The plant lost a lot of
SECTION A • Wear lightweight, light-coloured, loose- water.
1. C 2. A 3. A Adaptation: The stoma pores on
fitting clothing, and a wide-brimmed hat if the leaves are closed to reduce
SECTION B must do outdoor activities on a hot day. additional water loss from the leaf
to the environment.
1. (a) (i) Plant cell Formative Practice 3.1 (c) (i) Kidney
(ii) Animal cell (ii) Less than 58 ml/h. The body
(b) (i) used 1. We do not sweat a lot on a rainy day. loses a lot of water through
(ii) absorbed Therefore, the excess water in the body sweat.
will be removed from the body through
SECTION C urine. 4Chapter Reproduction

1. (a) Carbon dioxide + Water → Glucose 2. When our body temperature drops, the HPOraTkStisCFhoramllaetnifg1e 1
+ Oxygen heat production will increase and heat
loss will decrease through these actions: Tiger: Internal fertilisation
(b) Cellular respiration process Toad: External fertilisation
(c) • Can keep the balance • Blood vessels constrict. External fertilisation is less efficient because:
• Sweat less. • A large number of gametes are
of oxygen content in the • Hairs stand erect.
atmosphere. • Skeletal muscles will contract and released into the water and wasted.
• To support organism's life. • Gametes live for only a short time, and
(d) Photosynthesis process cannot be relax actively.
carried out without plants. When • Hormones will be secreted to many are lost in the water.
plants are depleted, the process • Offspring are often eaten by predators
of photosynthesis also decreases, increase the body metabolism.
resulting in lack of oxygen supply and reduces the chances of surviving
3. Dogs cannot remove much heat into adulthood.
3Chapter through sweating, so they always stick
Coordination and Response out their tongue which allows saliva to
evaporate from the tongue to reduce
the body temperature.

4. • Transpiration is the process of
losing water from the surface of
plant leaves in the form of water

vapour to the atmosphere through Formative Practice 4.1
stomata.

HPOraTkStisCFhoramllaetnifg1e 1 • Transpiration helps plants to absorb 1. (a) Sexual reproduction is the
and transport water and minerals production of offspring through the

from the soil to all parts of the fusion of a male gamete and a

Skin is the organ that plays an important role plants to replace the water lost to female gamete, whereas asexual

in regulating body temperature. Skin injuries the surrounding through the leaves. reproduction is the production

will affect the function of skin to sweat Transpiration also helps in cooling of offspring from a single parent

when the surrounding is hot. This will affect down the plants when water gets without involving any gametes.

the homeostasis of Sally's body because evaporated on a hot day. This (b) Internal fertilisation occurs inside

she cannot regulate her body temperature means transpiration helps plants the body of the female parent

well. Therefore, Sally can only stay in an to regulate water content and after the male parent deposits his

environment where the temperature can be maintain the water content to be in sperms into the female’s body,
maintained at a constant temperature. a balanced and stable condition. whereas external fertilisation
occurs outside the body of the

532

  Science PT3  Answers 

female parent where both sperms 3. (a) Waste substances such as carbon (b) (i) – Ali can wear a condom Form
and eggs are released into the dioxide and urea. before having sex to preventForm
water simultaneously by the male the sperm from entering the
and female parents. (b) Nutrients, oxygen and antibodies vagina during ejaculation.
2. Amoeba / Paramecium / Bacteria
3. To ensure survival and continuity of a HPOraTkStisCFhoramllaetnifg1e 3 – Nora may consume a
species. contraceptive pill to prevent
Fertilisation will occur and will produced two ovulation. 1
Formative Practice 4.2 different zygotes. The zygotes will develop
and form a pair of non-identical twins. – Nora may ask the doctor
1. (a) Sperm duct to insert Intrauterine
(b) Testis Formative Practice 4.5 contraceptive device (IUCD)
(c) Penis to prevent the implantation
2. Ovary 1. Calcium and phosphorus are of an embryo.
3. Similarities: needed for healthy, strong bones,
• Both are sexual reproductive cells. cartilages and teeth. Low calcium diet (ii) Yes
• Both carry genetic information. causes problems to the growth and – To enable married couples
development of bones, cartilages and to plan the amount of
Differences: teeth of the mother and foetus. children and choose the
• Sperm is the smallest human cell, right time to have children.
2. • Miscarriage – To help couples limit the
whereas ovum is the largest human • Premature birth size of the family to ensure
cell. • Stillbirth the stability of the family's
• Sperm is the male gamete, whereas • Low birth weight and mentally retarded economy and to increase
ovum is the female gamete. the family's quality of life.
• Sperm is produced by testis, Formative Practice 4.6 – To ensure that the mother's
whereas ovum is produced by ovary. health is not affected due to
• Sperms is able to move but ovum is 1. Take hormone pills or injections to the frequent of pregnancy.
not able to move. enhance the production of healthy and (c) The nutrition of a pregnant woman
4. (a) • Increased penis size mature reproductive cells. need to be rich with
• Growth of body hair, pubic hair,
2. No.This permanent contraception • Sufficient carbohydrates to
facial hair (beard, moustache or method requires minor surgery and is supply energy.
sideburns) and armpit hair. irreversible.
(b) • Development of breasts and • Proteins to build new tissues
widening of hips. Formative Practice 4.7 and to repair damaged tissue.
• Development of fat tissue under
the skin. 1. (a) P and Q • Calcium and phosphorus
(c) • Reproductive systems become (b) Q minerals to strengthen bones
mature. (c) Q develops into seeds while S and teeth.
• Produce reproductive cells and
secrete sex hormones. develops into fruit. • Iron to avoid anaemia.
• Vitamins to preserve the mother's
HPOraTkStisCFhoramllaetnifg1e 2 2. Advantages of cross-pollination:
• The new plants are healthier and health.
Urethra in the male serves as the pathway
for both semen and urine and is a part of the more resistant to diseases and pests. 5Chapter Matter
male reproductive system. For the female, • New varieties of plants may be
urethra only functions to excrete urine. HPOraTkStisCFhoramllaetnifg1e 1
produced.
Formative Practice 4.3 • Seeds produced are with improved The density of ice is 0.92 g cm-3. Therefore,
the ice will float on water and mercury but will
1. (a) 24th April quality and more viable. sink in turpentine.
(b) 21th – 26 th April • High-yield and better quality of fruits
(c) The ovum will die and will be Daily Application
are produced.
discharged as menstruation
2. • Take bath or shower at least once a 3. Sufficient water, suitable temperature
and adequate oxygen supply.
day.
• Use clean undergarments and PT3 Practice 4 Milk or other substances that contain alcohol.

change them regularly. SECTION A 4. C Formative Practice 5.1
8. A
• Change sanitary pad regularly, once 1. B 2. C 3. C 12. B 1. Matter is anything that has mass and
every six hours to avoid the feeling 5. A 6. D 7. A occupies space.
of discomfort. 9. C 10. C 11. A
2. Matter Non-matter
Formative Practice 4.4 SECTION B
• Salt • Rainbow
1. Fertilisation occurs in the Fallopian tube 1. (a) ii and iii • Shirt • Shadow
when a sperm fuses with an ovum to (b) (i) pollination agent • Duck • Bell sound
form a zygote. (ii) quality • Coconut tree • Light
2. (a) (i) and (ii)
2. Foetus is a more developed embryo by (b) Small. 3. Iron
the end of 2 months of pregnancy, with Has a long style.
all the essential external and internal Formative Practice 5.2
structures formed. SECTION C
1.
1. (a) (i) The menstrual cycle is an Matter Arrangement Movement of
organised menstruation cycle of particles particles
and ovulation. Solid
• Orderly • Vibrate
(ii) Phase L. One mature ovum is and closely about fixed
released from the ovary in this packed positions
phase.

533

  Science PT3  Answers

Liquid • Disorderly and • Move freely Good Electrical Poor except (b)
conductivity carbon Mixture
quite closely throughout Compound

packed the liquid High Melting point and Low Can be separated Can only be
boiling point Low easily by physical separated by
Gas • Very far apart • Move High methods such as chemical methods
Form Density filtration, distillation, such as electrolysis
Form and not in randomly in Solid separation and thermal
except using magnet, decomposition.
order all directions mercury sedimentation

2. The smell of durian spreads when its State of matter Solid, liquid or
small discrete particles mix with the air gas.

1 particles. The particles of durian smell (b) method, floatation
move randomly in various directions as method and

they diffuse from a higher concentration Element Difference Compound chromatography 6
region to a lower concentration region. Component method.
Therefore, we can detect the smell of Consists Consists of
durian when we are some distance of only atoms of PT3 Practice
away from a durian stall. one kind SECTION A
of atom. two or more
3. Condensation different
elements.

PT3 Practice 5 Ability to be 1. A 2. D
broken down

SECTION A Cannot into simpler Can SECTION B
substances
1. B 2. B 3. A 4. D 5. C by physical or 1. (a) (i) Floatation
chemical method Distillation
SECTION B (b) (i) and (iii)
TIMSS Challenge 2
1. (a) (i) Condensation SECTION C
(ii) Melting 1. (a) Electron
(b) (i) and (iv)

SECTION C D (b) 3
(c) Atoms are neutral because they
1. (a) Density is the mass of a substance HPOraTkStisCFhoramllaetnifg1e 1
in one unit of volume. Food X is not safe to be sold in the market have the same amount of protons
because it contains dye C which is harmful and electrons. If the amount of
(b) (i) The air in the float is less to the health of the public. electrons is 3, then the number of
dense than water. Therefore, protons is also 3.
the float can float on water. Formative Practice 6.2 (d) Proton and neutron
(e) (i) Neutron
(ii) The block of wood is less dense (ii) Electron
than water. Therefore, the block
of wood can float on water and

be carried along the river. 1. Cocktail / Sandwich / Air / Blood / Soil 7Chapter Air
/ Sea water / Petroleum / Milk / Orange
(c) • Salt is formed when seawater Formative Practice 7.1
evaporates (Liquid → Gas). juice / Bronze

• Water boils and turn into steam 2. (a) Distillation
when heated (Liquid → Gas). (b) Sedimentation method
(c) Floatation method
• Chocolate melts in hot weather
(Solid → Liquid).

6Chapter Formative Practice 6.3 1. Nitrogen, oxygen, carbon dioxide,
inert gases, water vapour, dust and
Periodic Table 1. Sodium and chlorine microorganisms.
2. Burning of paper is a chemical change
TIMSS Challenge 1 2. • The components of air are not
and not a physical change because chemically combined.
Element P and Element R.
• new substances are formed. • The components of air can be easily
Formative Practice 6.1 • the properties of the original separated by a physical method.

1. Atom is neutral because the number substance and products are not the • The properties of air are same as the
of electrons in an atom is equal to the properties of its components.
number of protons. Thus, the negative same.
charge of the electrons cancels out the • Each gas retains its original
positive charge of the protons. • the original substance and products properties when separated.
have different chemical compositions
2. Periodic Table is a list of elements 3. • The oxygen cycle is the process that
arranged in the order of increasing • the reaction is irreversible. involves the intake, consumption and
proton numbers. release of oxygen continuously into
3. (a) the atmosphere. The required oxygen
3. (a) is obtained from photosynthesis.
Physical change Chemical change
Metal Difference Non-metal • The carbon cycle is the process that
• Type and • Type of atoms is involves intake, consumption, and
Shiny Appearance Dull arrangement unchanged. release of carbon continuously into
of atoms are the atmosphere and is maintained by
Ductile Ductility Brittle unchanged. • Arrangement processes such as photosynthesis,
and combination respiration, combustion and
Malleable Malleability Non-malleable • Type of molecules of atoms are decomposition.
is unchanged but changed, involves
the arrangement making or 4. Combustion / Rusting / Decomposition
of molecules breaking of bonds of waste materials and dead organisms
and the distance between atoms.
between
molecules are • Type of molecules
changed. is changed.

High Tensile strength Low / Respiration

Good Heat conductivity Low

534

Formative Practice 7.2 factories will increase the   Science PT3  Answers 
concentration of pollutants in
1. the atmosphere. 2. When light that travels in a straight line
• These gases will dissolve in is blocked by an opaque object, the
rain water and form acid rain. light cannot pass through it. Thus, a
• Acid rain causes ponds and shadow is formed behind the opaque
ground water to be acidic. object.
Form • This will threaten plant life and
Oxygen Formaquatic organisms.
(c) • Bicycles cannot release smoke
Fuel but the burning of fossil fuels
in the engine of a car produces TIMSS Challenge 2
smoke.
Heat • The smoke from cars contain Light travels much faster than sound, so 1
various pollutants such as we can see the lightning before hearing the
2. Oxygen and heat. carbon monoxide gas, carbon thunder.
3. Water is denser than oil and will sink dioxide, sulphur dioxide and
nitrogen oxide. HPOraTkStisCFhoramllaetnifg1e 1
below the oil. Oil floats on water, and (d) • Carpool to work 7.45 am / 7.45 pm
with the oxygen from the atmosphere, • Use public transport
it keeps burning. Therefore, the fire • Use renewable energy sources
started by an oil cannot be extinguished • Switch off electrical appliances
by water. when not in use

Formative Practice 7.3 Formative Practice 8.3

1. The condition in which air contains a 8Chapter Light and Optics 1. (a) 30º Ray box
high concentration of pollutants that (b) 30º
may harm living things or damage non-
living things (c)

2. Causes: TIMSS Challenge 1 30° 30°
Sulfur dioxide and oxides of nitrogen
from industrial emissions and Position Q 60° 60°
combustion of fossil fuels in vehicles.
Formative Practice 8.1 Plane mirror
Effects:
• Acid rain corrodes concrete and 1. A real image is the image that can 2. When the light ray from other vehicles
be formed on a screen while a virtual strikes the reflective stripes on the
limestone structures, and accelerates image is the image that cannot be safety jacket of a motorcyclist, the light
the rusting process. formed on a screen. ray will be reflected into the eye of the
• Turns water acidic which becomes driver. So, the motorcyclist is easily be
not suitable for aquatic plants and 2. Virtual and upright seen by the driver of the other vehicle
animals. in front or behind him. This can reduce
• Causes soil to be acidic and infertile. 3. (a) 45º Object the risk of crashing by other vehicles at
Steps to overcome: Plane night.
• Introduce environment quality act mirror
and laws in Malaysia. Formative Practice 8.4
• Educate the public on the practices
to reduce air pollution. 1. (a) changes direction
• Install electrostatic filters in (b) greater
factory smokestacks and build the (c) refraction of light
smokestacks to at least 30 metres 2. Refraction of light
tall. 3. Twice

PT3 Practice 7 Plane Formative Practice 8.5
mirror
SECTION A 4. A 1. (a) refracted
1. D 2. B 45º (b) glass prism, spectrum
2. Red, orange, yellow, green, blue, indigo
SECTION B 3. D (b) Allows the viewer to see over
obstacles. and violet.
1. (a) (i) Cover the surface of the fuel 3. Dispersion of light is the splitting of
with a fire blanket: Oxygen is (c) Modify the simple periscope
removed. as below to observe the object white light into its component colours.
behind:
(ii) Spray some carbon dioxide HPOraTkStisCFhoramllaetnifg1e 2
layers onto the fuel: Heat is 45º Object
removed. White light is observed on the screen
Plane because the second prism recombines the
(b) Liquid and gas mirror seven colours to form a beam of white light.
2. (a) X: Oxygen
Y: Nitrogen Plane
(b) Respiration: Yes mirror
Photosynthesis: No
45º
SECTION C
Formative Practice 8.2
1. (a) Carbon monoxide, sulphur dioxide,
nitrogen oxide 1. (a) light
(b) straight line
(b) • Increase in the release of
sulphur dioxide gas and
nitrogen oxide from industrial

535

  Science PT3  Answers

HPOraTkStisCFhoramllaetnifg1e 3 (b) (i) Diagram 1.3: Green 3. Mantle convection is a slow creeping
Diagram 1.4: Blue motion of mantle materials caused
(ii) The primary colour filter only by convection currents carrying heat
in the asthenosphere layer. These
No, because sugar solution does not have allows the same light colours currents are able to move the Earth’s
any suspended particles in it. as it to pass through. Other crust resulting in phenomena such as
Form light colours will be absorbed earthquakes and volcanic eruptions.
Form
or rejected.

Formative Practice 8.6 (iii) Yellow
(iv) Green

1 1. Observer A: Blue (v) Yellow is the mixture of green Formative Practice 9.4
Observer B: Reddish and red. Therefore, the yellow
filter allows yellow light which 1. When someone steps into a quicksand,
only his feet would sink, but panicked
2. • The colour of the sky observed by is the same colour as it is as body movement will cause the person
to sink deeper.
them are different because they well as red and green light that
2. Advances in science and technology
observe the sky at a different time. formed it to pass through. The allow the invention of devices that could
Observer A observers the sky at green filter only allows green provide early warning for the occurrence
noon while observer B observes the light through it. Therefore, of tsunami. This let the public to be
better prepared to face the disaster.
sky at dusk. green is formed on the white
Formative Practice 9.5
• At noon, the Sun is vertically above 9Chapter screen.
the head, so the path of the 1. Humans first appeared on Earth during
sunlight through the atmosphere Earth the Cenozoic Era.
to reach the observer is short. The
2. The estimated age of the Earth is 4.5
blue light with a short wavelength Formative Practice 9.1 billion years.
is scattered the most in all
3. As age indicators / As paleoclimate
directions by the fine particles in indicators / As evidence of evolution /
As record of the survival of spesies.
the atmosphere. Therefore, the sky 1. Troposphere is heated by the heat
looks blue. reflected by the Earth’s surface. Formative Practice 9.6

• At dusk, the sunlight shines Thus, the temperature decreases 1. Flood will occur if surface water
horizontally, so the path of the when the layer is further away from increases.
sunlight through the atmosphere to the Earth’s surface. In other words,
reach the observer is longer. The the temperature in the troposphere 2. Economic minerals are minerals with
red and orange light with longer decreases with altitude. high ecomomic values which are
wavelength are less scattered extracted from the earth and processed
2. The dark zone of the ocean is very for various applications in industries,
along the light path and will reach construction and manufacturing.

the Earth without hindrance. Other deep and no light can reach it. 3. • Dead marine organisms were buried
in the seabed millions of years ago.
lights such as blue light with Therefore, it is rare to find plants in the
• After millions of years, the dead
shorter wavelength are scattered dark zone because photosynthesis is organisms became more embedded
into the earth below thick layers of
away and will disappear along the unable to take place without light. stone and mud.
long distance. Therefore, the sky
looks reddish. 3. The temperature of inner core is higher • Through the action of bacteria, partial
than the outercore. decomposition occurred due to the
lack of oxygen.
Formative Practice 8.7 Formative Practice 9.2
• The continuous decomposition
1. Yellow 1. Igneous rock, sedimentary rock and by bacteria under high pressure
metamorphic rock. and temperature finally produced
2. Addition of light is the mixing of primary petroleum and natural gas.
coloured lights to produce secondary 2. • Igneous rocks do not contain fossils
coloured lights, while substraction of while sedimentary rocks often
light is the process that occurrs when contain fossils.
an opaque object reflects the light of
the same colour with it and absorbs the • Igneous rocks are unlayared while
lights of other colours. sedimentary rocks are layered.

PT3 Practice 8 • Igneous rocks are formed from the
process of cooling and freezing
SECTION A of magma that flows out of the PT3 Practice
mantle while sedimentary rocks are
1. A 2. B 3. D 4. A formed by compression of deposited 9
materials carried by rivers, glaciers
SECTION B and wind. SECTION A

1. (a) Convex lens: The size of the image 3. Metamorphic rocks are formed when 1. A 2. B
is smaller than the size of the igneous rocks or sedimentary rocks
object. are exposed to very high pressure and SECTION B
temperature.
Plane mirror: The size of the image 1. (a) (i) Crust
is the same as the size of the Formative Practice 9.3 (ii) Outer core
object. (b) (i) constant
1. Endogenic process is caused by forces (ii) water vapour
(b) (ii) and (iii) from within the Earth while exogenic
process occurs on the Earth’s surface.
SECTION C SECTION C
2. Rainwater / Frosting / Sunlight /
1. (a) (i) Diagram 1.1: Magenta Microorganisms 1. (a) (i) Biosphere
Diagram 1.2: Cyan (ii) The hydrosphere supplies

(ii) Yellow water to human.

536

(iii) Prevents dangerous ultraviolet PT3 Practice 1   Science PT3  Answers 
rays from reaching the surface
of the Earth. SECTION A Formative Practice 2.2

(iv) – Ultraviolet rays that reach 1. D 2. B 3. D 4. A 1. (a) (i) Carbon dioxide
the Earth can cause cancer. 5. A 6. C (ii) Oxygen

– Ultraviolet rays can lower SECTION B (b) (i) Photosynthesis
the rate of photosynthesis of (ii) Respiration
green plants. 1. (a) (i) Durian, cow (c) Decomposition
(ii) Rafflesia, hornbill 2. Plants will release water into the
(b) – A body fossil is a remnant of (b) (i) Elephant atmosphere once again through
the body of an animal or plant (ii) Polar bear transpiration.
that became a fossil.
SECTION C Daily Application
– A trace fossil is a remnant of the
activities of an animal such as 1. (a) (i) The diversity of living The duck, because it is the predator to golden
foot prints, egg shells and many organisms on this Earth apple snails.
more that can be seen in fossils. includes plants, animals and
microorganisms.
(c) Fossil records reveal the species that
become extinct. (ii) Law enforcement because
perpetrators will be scared
Form 2 of harsh laws such as prison HPOraTkStisCFhoramllaetnifg1e 3
or fine with high amount.//
1Chapter Biodiversity Awareness campaign so that Snake are dangerous to humans because
the community will be aware snakes are poisonous animals.
of their role and the change in
Formative Practice 1.1 behaviour is long lasting. TIMSS Challenge 1

1. Habitat and climate (iii) Provide logs The rat population increases because of the
2. Animals – goats, chickens and cows; Build buildings / furniture // absence of the snake as the predator. / The
Plants – spinach, mustard leaves, mangoes Habitat for rattan rat population decreases due to the decreasing
3. Furniture industry, rubber products Build furniture // paddy population causing a break in the food
Herbal plants supply.
industry Produce medicine //
4. Advantages: Economic resource Food Formative Practice 2.3 Form
Vegetables / fruits from the Form
increases because of an increase in 1. Mutualism, commensalism and
agriculture products forest parasitism 2
Disadvantages : Destruction of wildlife’s (b) Restriction of fires // Can cause the
original habitats. 2. Yes, because breeding only occurs
burning of forest within the same species only.
HPOraTkStisCFhoramllaetnifg1e 1 Destroys the habitat of flora and
3. No, because the excessive use of
Elephant population has been threatened with fauna pesticides will destroy the soil.
extinction because poachers have been killing Restriction of throwing trash
the elephants for their tusks which are worth // Damages the scenery / 4. The plankton population dies. Plankton
millions of ringgit. Reduces tourist attractions needs an average temperature to
continue to survive.
TIMSS Challenge 1 2Chapter Ecosystem

B Goat Formative Practice 2.4

HPOraTkStisCFhoramllaetnifg1e 2 HPOraTkStisCFhoramllaetnifg1e 1 1. Good effect : The country’s economy
increases.
A bat is a mammal because it has obvious This is because of the increase of the rat
characteristics similar to a mammal’s, they population in the cornfields caused by the Bad effect: Destruction of habitats and
give birth, nurse its young, are warm-blooded absence of the prey, that is the snake eating environmental pollution.
and breathes through its lungs. the rat.
2. Cause: The drainage system is not
Formative Practice 1.2 Formative Practice 2.1 maintained properly, for example too
much of rubbish clogging the drains.
1. Help scientist identify clearly the 1. The producer is the organism that
characteristics of the animals. produces its own food whereas the Steps: Maintenance of the drainage
consumer is the organism that eats system at least one a month.
2. Vertebrates are animals with other organisms.
backbones, for example cows while 3. – Using organic fertiliser.
invertebrates are animals without 2. (a) Sparrow and frog. – Using biological control to
backbones like ants. (b) (i) Paddy → Rat → Eagle
(ii) Paddy → Grasshopper → Frog exterminate pests.
3. Can, like pine that produce seeds → Eagle
(cone) but not flowers. (iii) Paddy → Worm → Sparrow → PT3 Practice 2
Eagle
4. Monocotyledon have fibrous roots, one (c) The population of caterpillar SECTION A 3. D 4. A
cotyledon and paralleled vein leaves. increases. 1. B 2. D 7. B
While dicotyledons have tap roots, two 5. B 6. C
cotyledons and network-like vein leaves. HPOraTkStisCFhoramllaetnifg1e 2
SECTION B
TIMSS Challenge 3 Death animal and death plants will not decay.
1. (a) (i) Mutualism
D  Cockle, crab, cockroach, spider (ii) Prey-predator
(b) (i) The stem stores water //
The leaf is thorn-shaped //

537

  Science PT3  Answers

Long roots find water in the (iii) Large intestine 4Chapter Human Health
ground
2. (a) Protease
(ii) Resides on tall trees to obtain (b) Maltase
sunlight.
3. (a) To determine the presence of starch
SECTION C (b) To determine the presence of glucose Formative Practice 4.1

1. (a) Mutualism, Commensalism, Parasitism TIMSS Challenge 1 1. Infectious diseases are diseases that
(b) Has sharp claws and fangs to catch can spread from one individual to
prey No. No digestive process at the ileum. The another individual.
(c) Competing for mates does not process that takes place at the ileum is the
occur within different species absorption of digested food. 2. Pathogens are organisms that cause
because fighting for mates only illnesses while vectors are animals that
happens to organism of the same Formative Practice 3.4 transmit the pathogen from the host to
species. another individual. For example, the
1. (a) Small intestine dengue virus is carried by its vector,
(d) (i) Mushroom - saprofitism (b) Large intestine that is the Aedes aegypty mosquito.
Rafflesia - parasitism
2. (a) Vilus, its function is to increase the 3. (a) vibro bacteria, fly
(ii) – Mushrooms grow on dead surface area of the small intestine. (b) Denggue virus, Aedes aegpty
and decaying trees to obtain mosquito
nutrients from them while (b) (i) Blood capillary (c) Leptospira bacteria, rat
rafflesia grow on living trees (ii) to transport digested food to the (d) Influenza H1N1 virus, no vectors
and absorb nutrients from cells in the body. (c) Dermatofit fungus, no vectors
them.
3. Allows the digestive process to be 4. Air, water and touch.
– Mushrooms reside on carried out to the maximum.
dead trees while rafflesia HPOraTkStisCFhoramllaetnifg1e 1
can cause the host that is PT3 Practice 3
resided on to die. The child is not protected from diseases
SECTION A 4. A prevented by the vaccine and there is a
3Chapter Nutrition 1. D 2. C 3. D high probability of the child contracting such
5. B 6. A diseases.

SECTION B

Formative Practice 3.1 1. (a) (i) Cellulose (ii) Glycogen TIMSS Challenge 1
(b) (i) more (ii) less

1.
(i) Protein
Form Builds and repairs SECTION C Sofea has a good immune system. / Sofea
Form tissues does not touch or play too near Ah Mei.
1. (a) – Physical digestion produces
2 (ii) Carbohydrate Provides energy small food particles whereas Formative Practice 4.2
(iii) Fibre Prevents constipation chemical digestion produces
simple molecules. 1. Using the body’s defence mechanism
2.
– Chemical digestion involves
enzymes whereas physical (a)
digestion does not involve
2. Suffer from scurvy because lacking
vitamin C. enzymes. (b)
(b) Liver. Secretes bile that can
(c)
emulsify fat to fine drops and ease

HPOraTkStisCFhoramllaetnifg1e 1 the digestion by lipase. (d)
(c) (i) Protein digestion
P→epsin
(ii) Protein + Water
Polypeptide
Rice provides energy. Vegetables and fruits 3. Natural immunity is the antibody

contain vitamin C to maintain our health (d) Filled with fine projections known produced by the body while artificial

whereas fibres prevent constipation. Fried as villi to increase surface area for immunity is the antigen or antibody

chicken and fish provide protein which absorption. injected into the body directly.

repairs injured tissues. 2. (a) (i) Food that contains all food 4. Children are more susceptible to
classes that are required by diseases because their immune
Formative Practice 3.2 the body in correct quantities to system is weak and has not developed
fulfil the needs of the body. fully. Therefore, immunisation is very
1. Contains seven classes of food with the important for them.
correct ratio. (ii) Gender / Climate / Occupation
/ Age / Health condition / Body

2. Pregnant women need more energy size (any two) PT3 Practice 4
compared to women who are not (b) (i) Obesity
pregnant. This is because pregnant (ii) Stage 4 SECTION A 3. D 4. D
women need to pass nutrients to the Contains fat and oil 1. C 2. A 7. B
foetus. (iii) Regular exercise / don't eat 5. D 6. B

3. Amir, because he needs a lot of energy food with high cholesterol SECTION B
to carry out vigorous activities. (iv) – Carbohydrate - White rice,
1. (a) Group 1: Leptospirosis, H1N1
4. Eat according to the correct amount./ bread Group 2: Cancer, Diabetes
Eat at the fixed time. – Protein without fat - Fish,

grilled chicken, steamed

Formative Practice 3.3 meat (b) (i) infectious
– Fibre - Vegetables (ii) vector

1. (i) Stomach (Cucumber, tomato, salad) 2. (a) (i) Vector
(ii) Liver – Plain water (ii) Air

538

(b) (i) Immunisation Daily Application   Science PT3  Answers 
(ii) Antibody
Can use lime to remove rust stains on the – Citric acid is used in fruit juice
SECTION C clothes. 4. No, acid does not show its

1. (a) Not the same. Pathogens are TIMSS Challenge 1 characterisctic without the presence of
microorganisms that cause water.
diseases while vectors are animals Oil spill can kill animals and pollute the rivers/
that transfer pathogens from one seas. Formative Practice 6.2
organism to another.
Formative Practice 5.3 1. Hydrochloric acid + Ammonia →
(b) When a patient sneezes or Ammonium chloride + air
coughs, water droplets that contain 1. (a) Chlorination
pathogens will come out from the (b) Boiling 2. The fishy smell of the fish is caused by
patient's mouth and nose. These (c) Distillation the presence of a type of alkali, that
water droplets will be carried by (d) Boiling is amine. Washing your hands with
the air, anyone who breathes the lemon juice which is acidic in nature
air will have high chances to be 2. Reverse osmosis and ultraviolet ray neutralises the amine and gets rid of
infected with that disease. treatment. the pungent smell.

(c) – Wear masks when being 3. Reuse and recycle wastes. Treat TIMSS Challenge 1
around patients. dangerous industrial wastes.
A mixture of hydrochloric acid with sodium
– Patients close their mouth PT3 Practice 5 hydroxide solution produces a salt solution
and nose while coughing or that is sodium chloride which is neutral in
sneezing. characteristic. Therefore, this mixture does
not change the colour in both pieces of
(d) (i) Ringworm litmus paper.
(ii) Yes. Ringworm is an infectious
SECTION A PT3 Practice 6
disease caused by the
dermatophyte fungus. 1. A 2. D 3. B 4. A 5. D SECTION A
(iii) This disease can be prevented
from spreading with isolation SECTION B 1. D 2. C
methods which is devices,
items and personal clothes of 1. (a) (i) Homogenous mixture of two or SECTION B
the patient are isolated from more substances.
other people. 1. (a) (i) Acidic properties
(ii) Substance that dissolve in (ii) Alkali properties
5Chapter liquid.
(b) Acid + Alkali → Salt + Water
Water and Solution (b) (i) Alcohol Form
(ii) Turpentine Form

SECTION C SECTION C

Daily Application 1. (a) Solubility is the maximum dissolved 1. (a) (i) Acidic 2
substance that can be dissolved (ii) No because solution Q is alkali
To increase the boiling point of the water so in 100 ml of solvent at a certain
that food can be cooked longer. temperature. For instance, only 12 g and S might be acidic because
potassium sulphate is needed to there are no changes on the
HPOraTkStisCFhoramllaetnifg1e 1 dissolve in 100 ml of water at room blue and red litmus paper.
temperature. (iii) Acidic substance is a
The hairdryer produces hot air. The substance that turn the blue
presence of heat and wind increase water (b) (i) Most of the potassium sulphate litmus paper to red.
evaporation. Suzi’s clothes dry faster. dissolve in water but there are (iv) Function: The litmus paper
some that does not dissolve. is an indicator to determine
Formative Practice 5.1 This is because the solubility the acidity and alkalinity of a
of potassium sulphate is 12 substance.
1. Sweat evaporates faster in windy g/100 ml of water at room // Any suitable answer.
conditions. temperature. Other materials: pH paper //
Litmus solution // Universal
2. The effect of the surface tension force (ii) Saturated solution. indicator solution
causes droplets of water/ liquid to form (c) (i) Solution P is more concentrated (b) (i) The purple colour of the liquid
in spheres as they fall onto a surface. sample lessens because the
than solution Q. acidic lime weakens/neutralises
3. (a) Cohesive force (ii) P: Concentrated solution the alkalinity of the liquid
(b) Adhesive force Q: Dilute solution sample.
(d) No
Formative Practice 5.2
6Chapter Acid and Alkali 7Chapter
1. Solute – iodine crystals; solvent –
alcohol; solution – antiseptic. Electricity and Magnetism

2. (a) P: Suspended solution; Q: Collloid; Formative Practice 6.1 HPOraTkStisCFhoramllaetnifg1e 1
R: solution
1. (i) Sour; The female pupil’s hair is charged with
(b) P: Milk, Q: Cream cake, R: Sugar water (iii) Corrosive; the same charges that is the positive
(c) Mixture P (ii) . 7; charge. The same charges push against one
3. (a) Acetone (iv) Blue to red another causing the strands of hair to stand
(b) Borax solution upright.
2. Acid and alkali are used as cleaner
agents because both are corrosive that
can remove stains.

3. – Nitric acid is used as fertiliser.

539

  Science PT3  Answers

Daily Application 2. If the direction of the current is reversed – Number of turns: The more
the direction of the magnetic field number of turns, the higher the
When a person walks, electrons are produced will change while the pattern of the strength of the electromagnet.
as a result of friction between the carpet and magnetic field remains the same.
the shoes. Electrons are dispersed to the (f) Electric bell // phone holder //
whole of the surface of the skin. A person 3. (i) Current flow through the conductor electric circuit breaker // relay
would feel the electric shock when he touches (ii) Number of wire coils switch // vehicle engine starter
the door knob/ metal because the electrons
on the hand attract the positive charges on 4. The electromagnet is a temporary 8Chapter Force and Motion
the door knob. magnet. It can be magnetised and
demagnetised easily. Therefore, when HPOraTkStisCFhoramllaetnifg1e 1
Formative Practice 7.1 the current flows, the iron core becomes
a magnet and lifts scrap metal and
when the current is disconnected, the
scrap metal drops.

1. Water and Sun. 5. The empty space shows there is no No. The weight of an object depends on the
magnetic field in that area and this area gravitational pull in an area. The stronger the
2. Metal chains are fixed to the back of gravitational pull the heavier the object.
the oil tanker to channel electrons, is known as the neutral point.

produced as a result of friction between PT3 Practice 7
the body of the tanker and air to the
earth. SECTION A Formative Practice 8.1
3. 40 cm = 2 Ω, 100 cm = x Ω
1. D 2. A 3. C 4. B 1. (a) Gravitational force.
40 2 (b) Frictional force.
100 = x SECTION B
2. Measuring it using the spring scale.
x=5Ω 1. (a) (i) Energy that is generated 3. More than 2 N.
from animal waste and 4. 100 N
4. R = V decomposition of living things
I such as plants and animals. TIMSS Challenge 1

I= 3 = 0.5 A (ii) Heat energy from the Earth’s In liquid Y, because the object has higher
6 crust due to very high density than liquid Y.
temperature of the Earth's core.
Formative Practice 7.2
(b) (i) Potential energy

1. (a) The brightness of bulb P and Q is (ii) Kinetic energy HPOraTkStisCFhoramllaetnifg1e 2
the same. SECTION C
When water flows out from the tank, there is
(b) Bulb P does not light up because the 1. (a) (i) empty space inside that tank that becomes

circuit is not complete.
N
N1111 semi vaccuum and low pressure. The
R 2 2 2 outside pressure which is higher prevents
Form Q the water from flowing out. Opening the lid/
Form cap allows air to enter the tank and push the
2. (a) = + + water out.

2 R = 0.67 Ω V
(b) I= R

I= 3 = 4.48 A
0.67 (ii) The neutral point is the point
HPOraTkStisCFhoramllaetnifg1e 3
(c) 4.48 A = 1.49 A where there are no magnetic
3 field lines. The packet of potato chips will expand
(b) The closer the magnetic field lines, because the pressure inside the packet is
TIMSS Challenge 1 the stronger the magnetic field. higher compared with the outside pressure.
(c)

North

NS NS Iron Formative Practice 8.2
nail
1. Water, raw egg, salt water, cooked egg.
2. (a) First class lever

(b) Scissors, plier

HPOraTkStisCFhoramllaetnifg1e 2 Battery Sum of force
Surface area
3. Pressure =

The total number of clips attracted increases. Copper wire = 10
This happens because an increase in the Switch 0.5 × 10–4
diameter reduces the wire resistance.
Therefore, the current that flows increases. = 2 × 105 N m–2
The more current that flows through the
conductor, the stronger the electromagnet. PT3 Practice 8

Formative Practice 7.3 South SECTION A 4. D

1. An electromagnet is a material with (d) Current and number of turns 1. B 2. B 3. D
temporary magnetic effects when the (e) – Current: The more current 5. A 6. C
current flows through the conductor.
that flows in a conductor, the SECTION B
stronger the electromagnet.
1. (a) (i) Push

540

(ii) Pull HPOraTkStisCFhoramllaetnifg1e 2   Science PT3  Answers 
(b) (iii) and (iv)
Every layer of clothing will trap layers of air (e) Take off the tight bottle cap by
SECTION C inside it, thus preventing heat from escaping. soaking the bottle cap into hot water.
This gives multiple insulators.
1. (a) Suitable, because the tire is wide 1 0Chapter Sound Waves
and does not easily sink into the
sands of the beach. Formative Practice 9.3 TIMSS Challenge 1

(b) – A wide tire can reduce pressure. 1. Mercury is used in liquid thermometers Faiq. This is because Faiq’s string is taut while
– A more elastic shock absorber because it is a liquid that expands Naqib’s string is slack. Slack strings cannot
and contracts fast with the change in transfer sound wave.
can absorb force effectively temperature.
and makes driving more Daily Application
comfortable.
(c) Produces a better grip on the beach. Sound reflection in the bedroom can be
reduced by adding sound absorbers such
(d) (i) Pressure = 1150 2. (a) as putting carpets, hanging up curtains and
0.4 placing soft sofa sets.
Aluminium
Formative Practice 10.1
= 2875 Nm-2
1. Sound is produced from vibrating
(ii) Pressure = 1150 = 700 Invar objects.
0.4
(b) (i) Electric iron 2. In outer space, there are no air
= 4625 Nm-2 (ii) Fire alarm particles, only vacuum. Therefore,
sound waves cannot be transferred.
(e) Helmet and face mask 3. To enable the roads to expand on a hot
day without cracking. 3. Sound is clearly heard through solids
9Chapter Heat compared to air. This is because the
arrangement of particles in solids is
Formative Practice 9.1 TIMSS Challenge 1 more compact and causes the next
particle to vibrate fast as well.
(a) The quantitiy of heat received by the Brighter clothes are poor heat absorbers;
water is the same because the total therefore you would feel cooler in hot weather.
amount of power supplied to the heater
is the same. Formative Practice 9.4

(b) The temperature of the water in beaker (a)
A is higher than the temperature of
the water in beaker B. This is because Type of Heat Heat release HPOraTkStisCFhoramllaetnifg1e 1 Form
the volume of beaker A is smaller. surface absorption Form
Because the total amount of heat that
is absorbed is the same, the degree of Dark Good Good
heat in beaker A is bigger.
Bright Weak Weak The wave frequency produced by a 2
supersonic aircraft is so high that it is
Dull Good Good capable of vibrating the particles in mirrors
until the mirrors break.
Daily Application Shiny Weak Weak

The convection current is used to maintain (b) A bright and shiny surface because it is Formative Practice 10.2 √
the cooling temperature in buildings. Hot slow in releasing heat compared to a dark
air moves upwards and out through the and dull surface. 1.
ventilation holes and space in the roof. Cold
air will in turn flow in through the windows PT3 Practice 9
and doors.

SECTION A

HPOraTkStisCFhoramllaetnifg1e 1 1. C 2. A 3. B 4. A
5. C 6. A 7. D
The iron spoon is a good heat conductor. It
conducts heat faster to its surroundings, thus SECTION B
the water cools faster.
1. (a) (i) Heat conductor 2. When an observer goes closer to
Formative Practice 9.2 (ii) Heat insulator the stationary police car’s siren, the

1. Cold air flows to the bottom of the (b) (i) and (ii) frequency of the waves increase.
refrigerator because cold air is denser
while hot air which is less dense will SECTION C Formative Practice 10.3
move upwards. In this manner, the
inside cooling is circulated efficiently. 1. (a) Conduction 1. (a) 20 000
(b) – Replace the glass beaker with a (b) Megaphone amplifier
2. The space between the Earth and (c) hard
the Sun is actually a vacuum. In a metal container, so that heat is
vacuum, there are no particles that can transferred quicker 2. Bat and dolphin
transfer heat through conduction and – use wider glass beakers so that
convection. the surface area for heat transfer PT3 Practice 10
is larger
3. Metals are good heat conductors while (c) A towel will trap air. Air is a heat SECTION A
a plastic spoon is a heat insulator. insulator that slows the transfer of
heat to the environment. 1. B 2. B 3. A
(d) The air in the ping pong ball becomes
hot through transfer of heat. Hot air
will expand.

541

  Science PT3  Answers

SECTION B SECTION B Formative Practice 12.1

1. (a) (i) 1. (a) (i) and (iii) 1. 4.19 A.U, 6.61 × 10–5 ly
(b) (i) A region that has a very strong

gravitational attraction such 2. The time the Moon takes to rotate on its

that things are sucked into it axis is the same as the time taken for

including light. the Moon to move around the Earth.

(ii) A large cloud that consists of 3. The Earth is situated closer to the Sun
dust and gas such as helium compared to Mars. Therefore, the Earth

and hydrogen. gets more sunlight compared to Mars

(ii) 2. (a) (i) Supergiant star and increases the temperature on the
(ii) Supernova surface of the Earth.

(b) (i) False 4. – Contains oxygen and carbon dioxide
(ii) True which are necessary for respiration

SECTION C and photosynthesis.
– Contains a high content of water for

1. (a) That star will be sucked into the all life processes.

black hole as the black hole has
very strong gravity.
SECTION C (b) For spiral galaxies, research shows PT3 Practice 12

1. (a) – Waves emitted by the that young stars are at the arms SECTION A
transducer which moved on top or branches of the galaxy while 1. D 2. A 3. B
old stars are at the centre of the
of the mother's abdomen.
galaxy.
– Repeated reflections are (c) The Milky Way galaxy is an SECTION B
received by the transducer.
illustration of astronomers because
– Information from the reflection the telescope needs to be outside 1. (a) (i) Moon
will form an image on the of the galaxy in order to take (ii) Earth
screen. a picture of the galaxy. This is (b) (i) Mars
impossible because the Earth is (ii) Neptune
(b) – Does not endanger the baby located inside the Milky Way. The
while in carriage. SECTION C

– Can be done regularly or Milky Way is very big and to send
a telescope out from it would take
Form repeatedly millions of years. 1. (a) – The Sun rises in the east and
Form – Not painful (d) Blue stars are stars with the sets in the west.
(c) – To determine the depth of the highest temperature and brighter
light. Most blue stars are old stars – The position and length of the
ocean that are bigger than red and yellow shadow changes every day.
– To determine the position of a stars.
(e) Students can download a skyview – Day and night occurs.
group of fish by fishermen software onto the cell phone and (b) – The natural phenomena will be
– To detect cracks in engine parts point it to the sky. The telephone
screen will show the position of disturbed.
2 – To clean ornaments constellations and planets in the – Dramatic rise of water at one
(d) 3.5 – 7 MHz direction of pointing.
(e) Stethoscope and megaphone part of the Earth will cause
(f) High amplitudes cause damage to tsunami.
ear drums. – Day and night is longer on two
different parts of the Earth.
1 1Chapter Stars and Galaxies in the 1 2Chapter (c) • Use public transportation or
Universe carpool
• Practice 5R, or is avoid using
Solar System materials that cannot be
recycled
HPOraTkStisCFhoramllaetnifg1e 1 • Use energy-saving equipment
• Collect rain water to water

No, the Sun is an average size star. At the HPOraTkStisCFhoramllaetnifg1e 1 plants and wash cars
(d) The planet that does not have an

end of its lifespan, the Sun would become a atmosphere: Mercury

white dwarf. The kilometre unit is not suitable to be used Sunshine directly reaches
because its value is too big and difficult to its surface causing very high
Formative Practice 11.1 be managed. temperature of 427 °C.
• In dark parts, the surface
1. A nebula is a group of large clouds TIMSS Challenge 1
made up of dust and gasses such as temperature is very low up till
hydrogen and helium. The distance of the Moon from the Earth is -173`°C because there is no
shorter compared to the distance of Jupiter atmosphere to trap the heat.
2. Galaxies can be classified according to from the Earth, therefore the Moon seems • Planets with an atmosphere:
the shapes of the galaxies. bigger. Venus, Earth and Mars
• Earth and Venus have thick
3. Salmah can observe the stars using clouds that reflect sunshine but
sofwares such as Stellarium which

shows a realistic view of the sky similar the atmosphere also traps heat

to using our naked eyes, binoculars or which lead to the greenhouse

a telescope. HPOraTkStisCFhoramllaetnifg1e 2 effect.
• Venus has the highest

PT3 Practice 11 No, although water has been found on Mars, temperature due to its
atmosphere layer that has an

SECTION A the oxygen content on Mars is very low and overly high carbon dioxide

1. B 2. C 3. A 4. C it is difficult for living things to survive there. gas content until it causes the
greenhouse effect.

542

  Science PT3  Answers 

1 3Chapter Meteoroid, Asteroid, Comet shine, sending a jet, sending a Formative Practice 1.4
nuclear bomb to break it up into
smaller pieces before it reaches 1. Monocular and stereoscopic vision
the Earth.
HPOraTkStisCFhoramllaetnifg1e 1 (c) The moon does not have an 2. Statement Monocular Stereoscopic
atmosphere to protect itself from (a) 
Asteroid, because the size of the asteroid impacts of small objects. This is
is bigger than the meteoroid. Therefore, its because the surface of the moon is (b) 
impact is greater. also filled with sand and stone.
(c)  
Form 3
(d) 
HPOraTkStisCFhoramllaetnifg1e 2 1Chapter Stimuli and Responses
(e) 
The collision between the Earth and a large HPOraTkStisCFhoramllaetnifg1e 1
asteroid is capable of interfering with the 3. To move in the dark. It detects the
speed of the Earth’s rotation on its axis. Coughing is a voluntary and involuntary action. reflection of the sound waves of objects
When this happens, the gravitational pull in the surroundings, allowing the bats to
of the Sun and the planets influences the Formative Practice 1.1 fly in the dark.
Earth and attracts the Earth towards it. This
causes the Earth to slip out of its orbit. 1. (a) receptor 4. To attract the attention of the male
(b) impulse cockchafer.
Formative Practice 13.1 (c) nerve cells
(d) brain PT3 Practice 1
1. – An asteroid is bigger than a (e) effector
meteoroid. SECTION A

– An asteroid has its orbit while the 1. D 2. C 3. D 4. A
meteoroid does not.
SECTION B
2. Meteoroids move freely in space and
are influenced by the Sun and planets HPOraTkStisCFhoramllaetnifg1e 2 1. (a) P: Semicircular tube
around them. Q: Cochlea
The front of the eye lens is curved; it bends the (b) P - Helps to balance the body
3. The Moon has many craters because light, produces inverted image on the retina.
of the absence of atmosphere that can Q - Changes sound waves to nerve
burn the meteoroid. Formative Practice 1.2 impulses

4. Apollos and Atens. 2. (a) (i) True
(ii) False
(b) (i) short-sightedness
(ii) thin

1. Sensory SECTION C
organs
PT3 Practice 13 Stimuli detected 1. (a) (i) Monocular
Eyes (ii) Has a wide range of vision.
SECTION A Ears Light
Nose This animal can detect
1. A 2. D 3. B Sound predators around it more
Tongue effectively.
SECTION B Chemical substances (b) (i) Sees small objects such as
Skin in air bacteria // Sees far objects
1. (a) (i) Meteor such as planets.
(ii) Meteoroid Chemical substances (ii) Use microscope // Use
(b) (ii) and (iii) in food telescope
(c) (i) The cornea of the eyes is not
SECTION C Touch, temperature, flat. The light from the object
pressure cannot be focused onto one
1. (a) - The asteroid will give a bigger point on the retina.
impact. 2. Rod cells and cone cells (ii) Possible. Use cylindricalForm
3. Outer ear, middle ear and inner ear spectacles.Form
- An asteroid is a big rock or a 4. Reduce the risk of injury / bleeding (d) Watching television too close //
mixture of rock and metal in the Seeing the screen of a smartphone 3
Solar System. when a person falls in the dark.
2. (a) (i) Tropism response happens
- A meteoroid is a piece of rock 5. Sour, salty, sweet, bitter and umami very slowly but nastic response
or metal that originates from the happen very quickly.
splinter of asteroids or comets Formative Practice 1.3 (ii) Phototropism / Hydrotropism /
that orbit the Sun. Geotropism / Thigmotropism /
1. Geotropism, hydrotropism, phototropism Photonastic / Thermonastic /
(b) Find: Find asteroids that can threaten and thigmotropism Seismonastic
the safety of Earth (b) No.
2. (a) Root It will not grow towards the sunlight
Track: Make many observations (b) Root / window / door because there
with telescopes to predict the (c) Shoot/ Leaf is not enough light to carry out
orbital movement of the asteroid (d) Root photosynthesis.
(c) (i) Absorbing moisture in the air
Define characteristics: To 3. A tropism depends on the direction causes the environment in the
understand the characteristics of the stimulus whereas a nastic beaker to be dry / without air
of the asteroid such as rate of movement does not depend on the
rotation, composition and physical direction of the stimulus. A nastic
characteristics movement occurs more quickly
compared to a tropism.
Deflect: There are several
techniques that can be used to
deflect an asteroid such as laser

543

  Science PT3  Answers

(ii) J - Roots grow upwards HPOraTkStisCFhoramllaetnifg1e 2 (c) – Enforce the law: Harsh actions
towards the area of moisture cause people to be afraid of
that is found in the area The blood that contains oxygen is bright red doing the wrong things
outside the beaker. in colour. Fresh fish still has oxygenated blood
in the gills. – Awareness campaign: Increase
K - Roots grow downwards in responsibility and civic
the direction of water. Formative Practice 2.4 awareness to obey the rules
without force
(iii) Roots grow in the direction of 1. (a) Frogs – Moist skin
water. (b) Grasshopper – Trachea
(c) Fish – Gills
2Chapter 3Chapter Transportation
2. The gill surface is layered and covered
Respiration with numerous blood capillaries.

Formative Practice 2.1 3. Spiracles – Openings that allow air to Formative Practice 3.1
enter the body
1. Inhalation and exhalation 1. To transport oxygen and nutrients from
2. Oxygen and carbon dioxide 4. To gain more oxygen. This will be the environment to all body cells and
3. (a) Alveolus used to generate energy for muscle remove the waste materials from body
movement. cells to the environment.
(b) Trachea
(c) Diaphragm 5. Normal blood cells are biconcave, while 2. (a) Simple
4. Inhaled air is the air in our the blood cells of a person who suffers (b) small / fine
surroundings, ie atmospheric air. This from sickle cell anaemia are crescent- (c) diffusion
air contains higher oxygen content than shaped. The crescent red blood cells (d) amoeba
exhaled air. have abnormal haemoglobin (oxygen-
carrier pigment), thus affecting the rate HPOraTkStisCFhoramllaetnifg1e 1
Formative Practice 2.2 of oxygen transported in the body.
C

1. Diffusion Formative Practice 2.5 HPOraTkStisCFhoramllaetnifg1e 2
2. Oxygen diffuses into the blood in the
1. oxygen, carbon dioxide, stoma, diffusion Side of the neck
blood vessels and combines with the 2.
haemoglobin to form oxyhaemoglobin. Formative Practice 3.2
When it reaches the body tissues, 3. The stoma on the leaves will be coated
oxyhaemoglobin releases oxygen. by dust and dust particles. Therefore, 1. Left ventricle. The ventricle pumps
Oxygen then diffuses into the body oxygen cannot enter and carbon dioxide oxygenated blood into other parts of the
tissues. cannot get out of the leaves. The rate body (except the lungs).
3. The alveolus has a large surface of respiration and photosynthesis of the
area, very thin walls, moist surfaces plants will be affected. 2. To allow blood to flow in one direction
and is covered with numerous blood only
capillaries. PT3 Practice 2
3. This increases blood pressure and flow
HPOraTkStisCFhoramllaetnifg1e 1 SECTION A 4. D rate, thereby speeding up the delivery
1. C 2. B 3. A of nutrients and oxygen to the body
Haze is air pollution caused by the presence 5. C 6. D tissues.
of fine dust and harmful gases such as
carbon monoxide and sulphur dioxide SECTION B 4. Artery, vein and capillary
which cannot be seen by the naked eye 1. (a) B and C
and are floating in the air. Dust and these (b) (ii) and (iii) Formative Practice 3.3
harmful gases can get into the lungs during
breathing and affect the human respiratory 1. Red blood cell, white blood cell, platelet
system. So, it is desirable for Helmi to cover and plasma
his nose and mouth.
2. Blood group A, B, AB and O.
Formative Practice 2.3 3. Blood group A and O.
4. Patients with AB blood group can

receive blood from all blood groups.

1. Nicotine, sulphur dioxide and carbon SECTION C Formative Practice 3.4
monoxide
1. (a) (i) X - Carbon monoxide 1. (a) Transpiration is the evaporation of
2. Disease: Asthma Y - Sulphur dioxide water from the aerial parts of the
Causes: Cigarette smoke (ii) X - Competes with oxygen to plant.

Symptoms: Difficulty breathing and bond with haemoglobin (b) Low light intensity: The stoma closes
chest tightness Y – Irritate the respiratory tract. in dark conditions. This reduces the
(Accept other suitable answers) (iii) Install a catalytic converter rate of transpiration. Absence of air
movement: Water vapour tends to
3. A passive smoker is a non-smoker who // Use lead-free fuel // Use form at the bottom of the leaves and
is exposed to cigarette smoke from the renewable energy // Carpool around the stoma. This will reduce
smokers around them. (b) – The amount of oxygen in the rate of transpiration.
highlands is low.
4. The woman is a passive smoker. – Humans need to breathe with the
help of an oxygen tank.
3 Passive smokers also face the same
risk as smokers.
Form
Form

544

  Science PT3  Answers 

2. Xylem – Transports water and mineral oxygen. These elements tend to react 5Chapter Thermochemistry
salts with other elements such as oxygen,
Phloem – Transports products of carbon dioxide and sulphur to form
photosynthesis compounds.
3. Natural element minerals: Gold, silver,
Formative Practice 3.5 mercury Formative Practice 5.1
Natural compounds mineral: Calcium
1. Statement Human Plants carbonate, aluminium oxide (any 1. Endothermic: Photosynthesis, frying an
(a)   suitable answer) egg, evaporation of sweat, melting of
(b) 
(c)   Formative Practice 4.2 ice
(d)
(e)  1. To determine the method of extracting Exothermic: Respiration, combustion
(f)  of metal from its ore. of ethanol, decomposition of waste by

2. Zinc, Ferum, Tin, Lead and Copper bacteria in the soil, thermite reaction
3. Aluminium metal is located above
2. (a) Exothermic reaction   
carbon in the Reactivity Series of (b) Endothermic reaction
Metals. Carbon is the less reactive than
aluminium, thus carbon cannot remove PT3 Practice 5
aluminium from bauxite.
SECTION A 4. C

2. The materials needed for cell survival Formative Practice 4.3 1. D 2. A 3. A
cannot be delivered to the cells and the
SECTION B
waste materials cannot be removed.
1. (a) (i) True
1. – Electrolysis of molten ores by using (ii) False
carbon electrodes (b) (i) released
(ii) heat energy
– Heating metal oxide with carbon in a
PT3 Practice 3 5. B blast furnace. SECTION C

SECTION A 4. A 2. (a) Carbon 1. (a) (i) Exothermic reaction, heat is
(b) Carbon can remove lead from tin released to the environment
1. C 2. D 3. C oxide, so pure tin metal can be
obtained. (ii) Endothermic reaction, heat is
SECTION B (c) Greenhouse effect. Carbon dioxide absorbed from the environment
gas traps heat.The increase in
1. (a) (i) Mammal percentage of carbon dioxide gas (b) (i) Apparatus X: Thermometer
(ii) Fish in the atmosphere will cause an Parameter: Temperature
increase in atmospheric temperature. (ii) The student's mistake is using
(b) X: Red blood cell
Y: Platelet 3. – Develop a former mining site to a a glass cup because glass will
SECTION C recreation site absorb heat that is released
during the thermochemical
1. (a) (i) Has one ventricle // Has three – Phytoremediation method in recovery reaction. The student needs to
lung cavities of soil contaminated by heavy replace the glass cup with a
metals. polystyrene cup.
(ii) Frog / Salamander / Newt (c) (i)
(iii) • Oxygenated blood and
deoxygenated blood mixes Bamboo
• Blood that is pumped to
the body tissues have less PT3 Practice 4 Ziplock plastic bag
oxygen
SECTION A Vinegar
(b) (i) Pulmonary circulation system Limestone
(ii) Carries blood from the heart to 1. B 2. D 3. A 4. D

the lungs and back to the heart. SECTION B
(iii) – The amount of oxygen in R
1. (a) (i) Aluminium (ii) • Crush the chalk into small
is higher than in Q (ii) Iron pieces and put them into
– Q carries oxygenated blood the zipped plastic bag.
(b) Element: Gold, Diamond
from the heart to the whole Compound: Magnetite, Marble • Mix some vinegar into the
body whereas R carries plastic bag until it is half full.
deoxygenated blood from SECTION C
the body tissues • Put a bamboo stick and zip
– The pressure in R is higher 1. (a) (i) Supplies oxygen the plastic bag.
than in Q
• The reaction between
(ii) Avoids mixing of potassium the chalk and vinegar will
release heat because the
4Chapter permanganate powder with the neutralisation reaction
of acid and base is an
Reactivity of Metals metallic powder which might exothermic reaction.

cause an explosion

Formative Practice 4.1 (b) Magnesium

1. Earth’s crust Zinc more reactive Form
2. Natural element minerals are less Copper Form
6Chapter
reactive towards oxygen. These Argentum Electricity and Magnetism
elements do not combine chemically
with other natural elements. Natural (c) (i) Magnesium + Oxygen →
compound minerals are composed
of elements that are reactive towards Magnesium oxide

(ii) Copper + Oxygen → Copper Formative Practice 6.1 3

oxide 1. – Renewable energy can be used
continuously but non-renewable
energy cannot be used continuously.

545

  Science PT3  Answers

– Renewable energy does not pollute 3. By looking at the number of stars 5. Yes, because it needs more energy to

the environment but non-renewable on the energy efficiency label of the do work to oppose gravitational force

energy does pollute the environment. refrigerator. One star refer to low energy when moving upwards

2. Chemical energy → Heat energy → efficiency while five stars refers to very 6. (a) True (b) False
Potential energy → Kinetic energy →
Electric energy high energy efficiency.

3. Hydroelectric generator – Water 4. (a) Voltage = 240 V Formative Practice 7.2
Thermal generator – Steam
Gas turbine generator – Hot gases Power = 1 500 W

4. (a) Alternating current (b) I = P 1. (a) Gravitational potential energy
(b) Direct current V (b) Kinetic energy
(c) Direct current, Alternating current
(d) Direct current = 1 500 (c) Gravitational potential energy
(e) Alternating current, Direct current 240
2. Gravitational potential energy = mgh
= 6.25 A = 5 kg × 10 × 1.2 m

(c) Cost = 1.5 kW × 2 h × RM0.20 per = 60 J 1
2
unit 3. Elastic potential energy = Fx

= RM0.60 1 500 2
2 1 000 100
Formative Practice 6.2 = ×  kg × 10 ×  m

PT3 Practice 6 = 0.05 J

1. (a) ✓ (b) ✓ (c) ✗ SECTION A 3. A 4. C Formative Practice 7.3
(d) ✓ (e) ✓ (f) ✗ 1. D 2. B 7. A 8. D
5. B 6. C
2. Voltmeter S 9. A 1. The principle of Conservation of Energy
3. VVps = NNps states that energy cannot be created
SECTION B nor destroyed but can be transformed
= 50 × 50 from one form to another.
100
2. (a) Gained kinetic energy
= 25 V 1. (a) (i) True
(ii) False = Loss of gravitational potential
4. (a) 40
(b) 20 V (b) P: Thermal electric generator energy
(c) 120 V Q: Turbine electric generator 1
(d) 50 2  mv2 = mgh

5. (a) Step-down transformer SECTION C 12 × 0.12 × v2 = 0.12 × 10 × 1.8 m
(b) Step-up transformer v2 = 36
1. (a) P: Step-up transformer v = 6 m s–1
6. NNps = VVps Q: Step-down transformer
R: Step-down transformer
(b) Ball’s kinetic energy
(b) Similarity: Both transformers have
26400VV = 1 two coils. = 1  mv2
4 2
Difference: The number of turns
∴ Ratio of turns of coil = 4 : 1 of the primary coil in transformer = 1 × 0.12 × 36
P is less than the number of turns 2
of the secondary coil whereas the
number of turns of the primary coil = 2.16 J
in transformer Q is more than the
Formative Practice 6.3 number of turns of the secondary PT3 Practice 7
coil.
1. 240 V SECTION A
2. (a) Neutral wire (c) The voltage of electricity that is
generated at the power station will 1. C 2. A 3. B 4. D 5. D
(b) Live wire be increase before passing through
(c) Earth wire a cable network to be sent to SECTION B
3. (a) 240 V consumers.
(b) 415 V 1. (a) (i) and (iv)
7Chapter (b) (i) True
4. Fuse, earth wire and circuit breaker. (ii) False

5. The 2-pin plug does not have the earth SECTION C
wire but the 3-pin plug does have the
earth wire. Energy and Power 1. (a) (i) Elastic potential energy.

Formative Practice 6.4 Formative Practice 7.1 = 1 Fx
2
1. Energy efficiency refers to less energy 1. Work = Force × Distance
required to do the same task. = 45 kg × 10 × 4.8 m = 1 x 25 N x 0.5 m
2

= 6.25 Nm (6.25 J)

2. Not equal. Energy efficiency can be = 2 160 J (ii) Yes, work is done. The quantity
improved via application of efficient of work done is equal to the
technology such as motor, lamp and 2. Work = Force × Distance elastic potential energy that is
other energy-efficient technology. = 540 kg × 10 × 1 000 m stored in the arrow string which
It involves investment and expert is 6.25 J.
Formadvice to choose the right technology. = 5 400 000 J
Form Meanwhile, energy saving can be (b) (i) Maximum potential energy:
improved via practices of correct use of = 5 400 kJ J and L
energy such as turning off the light and Maximum kinetic energy: K
3. (a) 12 s (ii) Yes, because according to the
3 electrical appliances when not in use, (b) Work = Force × Distance
using sunlight and many more. It does = 70 kg × 10 × 3 m Principle of Conservation of
not involve costs but only a change of Energy, the amount of energy
user attitude towards energy. = 2 100 J before the changes is the same
as the amount of energy after
(c) Man’s power = Work
Time

= 2 100 J
12 s

= 175 W the change.

546

8Chapter Radioactivity (d) Non-ionising radiation   Science PT3  Answers 
(e) Ionising radiation
(e)
3. Alpha, beta and gamma rays
4. Sievert
Formative Practice 8.1 5. Soil, rocks and plants This logo must be displayed on the
outer part of the storage container
1. (a) Antoine Henri Becquerel Formative Practice 8.4 of substance P to warn others to
(b) Wilhelm Rontgen be careful of the dangers of the
(c) Marie Curie 1. – To control the population of pests substance.
(d) Pierre Curie by hindering their breeding or killing
(e) Marie Curie them with gamma rays. (f) Shows that the substance inside it
releases dangerous ionising rays.
2. Becquerel (Bq) and Curie (Ci) – Gamma rays are used to mutate
3. (a) Radioactive materials are elements plant cells to generate new genes 9Chapter Space Weather
with high quality.
with an unstable nucleus. Formative Practice 9.1
(b) Radioactivity is a process 2. Employees who handle radioactive
waste should wear badges known 1. (a) ✓
whereby radioactive rays released as dosimeters to detect their level (b) ✗
spontaneously and randomly from of exposure to radioactive rays. (c) ✓
an unstable radioactive substance Photograph film on dosimeters will (d) ✗
change into a more stable element. change in colour when exposed to 2. (a) Sunspot
(c) The half-life decay concept of a radioactive rays. The black colour of
radioactive material is the time film shows the level of exposure to the (b) Solar flare
taken by radioactive atoms to rays. (c) Solar prominence
decay to half of its original number.
3. Radioactive materials and waste must 3. The surface of the Sun, the
4. Unstable elements can become be stored in a thick-walled container photosphere is constantly turbulent
stable elements when decay occurs made of concrete and lead. This due to the release of gases from the
spontaneously. container with waste is buried in a mine convection zone. The surface of the
that is not in use or is not inhabited by photosphere is seen uneven due to the
Formative Practice 8.2 humans. presence of granules.

1. (a) 4. Short-term effects – Nausea, vomitting,
lethargy
Nucleus Neutron
Electron Proton Long-term effects – Cell mutation,
tumours, infertility
Formative Practice 9.2
5. Alpha rays cannot penetrate paper like
beta rays 1. Space weather is the environmental
change around the space between the
6. – Sterilise food and surgical equipment atmosphere of the Sun and the Earth.
– Kill cancer cells and tumours
2. Activities that occur on the surface of
(b) Yes, because the number of protons PT3 Practice 8 the Sun.
(3) is the same as the number of
electrons (3). SECTION A 3. B 4. A 5. A 3. (a) Communication disruption
1. C 2. B (b) Aurora
(c) Atoms become positive-charged (c) Cell mutation
ions. SECTION B
4. An aurora occurs when the cosmic rays
2. Four 1. (a) (i) Discovered radium and polonium collide with the atoms and molecules in
3. Positive ions are formed when atoms (ii) Discovered radioactivity the Earth’s atmosphere.

lose electrons, while negative ions are phenomena
formed when atoms receive electrons. (b) X-rays, Gamma rays
4. (a) ✓
(b) ✗ SECTION C PT3 Practice 9
(c) ✗
1. (a) Substance P is a radioactive SECTION A
Formative Practice 8.3 substance which is an element
whose nucleus is unstable. 1. B 2. B 3. D 4. A
1. (a) Ionising radiation is electromagnetic
rays that have sufficient energy to (b) Substance P is undergoing 5. C 6. B 7. A 8. A
ionise atoms or molecules. radioactive decay (process X) to
change into a more stable element. SECTION B Form
(b) Non-ionising radiation is Form
electromagnetic rays that do not (c) Before process X, the nucleus 1. (a) (i) and (iii)
have enough energy to ionise of substance P is unstable but (b) (i) Magnetosphere 3
atoms or molecules after process X, the nucleus of (ii) Space weather
substance P becomes more stable. 2. (a) (i) Convection zone
2. (a) Non-ionising radiation (ii) Corona
(b) Ionising radiation (d) Carbon-14 // Iodine-131 // (b) (i) type G
(c) Ionising radiation Cobalt-60 (ii) denser

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  Science PT3  Answers

SECTION C Copernicus’s theory states that the Sun 4. The space exploration project is
is the centre of the universe. desirable because through this
1. (a) The Sun is categorised as a star exploration, we can unearth the secrets
4. The heliocentric theory is true because of Earth, planets and space objects /
because it can generate its own according to this theory, the Sun is search for new mineral sources from
the centre of the solar system and the the Moon, other planets and asteroids.
energy. planets circulate around the Sun in their (Other correct answers are acceptable)
orbits.
(b) Layer S
Formative Practice 10.2
(c) The Sun generates energy through
1. The technology used in space
nuclear fusion that occurs in its exploration allows humans to study
the universe and its objects in more
core. Nuclear fusion is a nuclear detail. For example, the use of space SECTION A
telescopes and space probes enables 1. B 2. B
reaction process whereby four astronomers to obtain direct information 3. D 4. C 5. A
about planets in outer space. In SECTION B
hydrogen atoms combine to form addition, the creation of rockets and
space shuttles allows astronauts and
one helium atom. During this appliances to be taken into space to
conduct space studies.
reaction, energy is released in the 1. (a) (i) ✗
2. Satellites are divided into several types (ii) ✓
form of photons (light particles). according to their respective functions: (b) (i) Kepler
• Communication satellites: Used for (ii) Ptolemy
(d) – Effects on technology radio communications and television
broadcasts SECTION C
and equipment on Earth • Weather satellites: Used to predict
Earth’s weather
for example high energy • Navigation satellites: Used by
airplanes and ships to determine
particles from the Sun hit their position accurately.

the communication satellites, 3. (i) As a research and development 1. (a) X: Satellite
centre in remote sensing Y: Space shuttle
causing a disruption of technology and other related Z: Space station
technologies such as GIS and
television broadcasts and GPS. (b) Y can be used repeatedly. Y can
transport astronauts from the
telephones. (ii) Involved in supplying satellite space station to the Earth again.
imagery of remote sensing to users.
– Effects on human health. (c) (i) The place for astronauts to do
research while being in outer
Radiation that is released space.

from the Sun can cause cell (ii) International Space Station
(ISS), Salyut 1, Skylab
mutations on the human body.
(d) We need to continue space
1 0Chapter Space Exploration exploration because the
information obtained will allow us
Formative Practice 10.1 to understand the evolution of the
Solar System, natural phenomena
1. Astronomy is a scientific field that and forces that affect the Earth.
studies the universe as well as the
objects in it.

2. Johannes Kepler, Aristarchus, Nicolaus
Copernicus

3. Ptolemy’s theory states that Earth
is the centre of the universe, while

Form
Form

3

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