Focus TG4 KSSM (Science) Terbitan Penerbitan Pelangi Sdn Bhd

CONTENTS

1Chapter Safety Measures in the 1 7Chapter Body Coordination 100
Laboratory

1.1 Personal Protective Equipment 2 7.1 Human Endocrine System 101
1.2 Disposal of Waste 4 7.2 Disruptions to Body Coordination 105
1.3 Fire Extinguishers 7 7.3 Healthy Mind 109
12 SPM Practice 7 112
SPM Practice 1
8Chapter Elements and Substances 115
2Chapter Emergency Help 14

2.1 Cardiopulmonary Resuscitation (CPR) 15 8.1 Matter 116
2.2 Heimlich Manoeuvre 17 8.2 Modern Periodic Table of Elements 118
20 8.3 Isotope 122
SPM Practice 2 SPM Practice 8 125

3Chapter Techniques of Measuring the 22 9Chapter Chemicals in Industry 128
Parameters of Body Health
23
3.1 Body Temperature 25 9.1 Alloy 129
3.2 Pulse Rate 29 9.2 Glass and Ceramic 134
3.3 Blood Pressure 31 9.3 Polymer 136
3.4 Body Mass Index (BMI) 34 SPM Practice 9 141
SPM Practice 3

4Chapter Green Technology for 36 1 0Chapter Chemicals in Medicine and 143
Environmental Sustainability Health

4.1 Environmental Sustainability 37 10.1 Traditional Medicine, Modern Medicine
and Complementary Medicine 144
4.2 Energy Sector 39 10.2 Free Radicals 150
4.3 Waste and Wastewater Management Sector 41
4.4 Agriculture and Forestry Sector 44 10.3 Antioxidant Substances 151
10.4 Health Products 152
4.5 Transportation Sector 45 154
4.6 Green Technology and Life 46 SPM Practice 10

SPM Practice 4 48 1 1Chapter Force and Motion 156

5Chapter Genetics 51 11.1 Linear Motion 157

5.1 Cell Division 52 11.2 Linear Motion Graphs 165
5.2 Inheritance 59 11.3 Gravitational Acceleration and Free Fall 169
5.3 Mutation 64 11.4 Mass and Inertia 172
5.4 Genetic Engineering Technology 69 176
5.5 Variation 71 SPM Practice 11
SPM Practice 5 74
1 2Chapter Nuclear Energy 180

6Chapter Support, Movement and Growth 77 12.1 The Use of Nuclear Energy 181
12.2 The Production of Nuclear Energy 183
6.1 Support, Movement and Growth 12.3 Impact of Using Nuclear Energy 186
in Animals 78 12.4 Nuclear Energy in Malaysia 188
6.2 Human Movement and Growth 86 SPM Practice 12 190
6.3 Support, Growth and Stability in Plants 91 193
97 PRE-SPM MODEL PAPER 203
SPM Practice 6
ANSWERS

iv

Chapter3 TPeacrahmnieqtueerss ooff MBoedaysuHrienagltthheChapter  Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health
Chapter
3

CHAPTER FOCUS

Body Temperature
Pulse Rate
Blood Pressure
Body Mass Index (BMI)
Athletes have pulse rates lower
than non-athletic individuals
because an athlete's cardiac
muscle is stronger.
In addition to the pulse rate,
what are the other important
parameters to measure the level
of our health?
22

Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

3.1 Body Temperature 5. Our body temperature is controlled by the
hypothalamus in the brain.

1. Temperature is a measurement of the degree 6. Body temperature keeps our body functioning Chapter
of hotness and coldness of a substance. optimally. Chapter

2. Body temperature is the measurement of the 7. A tool used to measure temperature is a 3
degree of hotness and coldness of the body. thermometer.

3. A normal human body temperature is 36.9°C. 8. There are many types of thermometers with
different functions.
4. The increase and decrease of our body
temperature shows that we may have health 9. Table 3.1 shows four types of thermometers
problems. that are commonly used.

Table 3.1  Types of thermometers and their functions

Clinical thermometer Laboratory thermometer

• Used to measure body temperature • Used to measure the temperature of liquids

• Measure temperatures in the range of 35°C − 42°C • Not suitable for measuring body temperature

• Can measure temperature with a precision of 0.1°C • Measure temperatures in the range of -10°C − 110°C

• Can measure temperature with a precision of 1°C

Rectal thermometer Infrared thermometer

• Used to measure body temperature through the anus • Used to measure body temperature without contact
with the body
• Usually used for infants below 3 months
• Temperature reading using this thermometer is very

quick

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  Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

Measuring Body Temperature with theChapter (c) Apply petroleum jelly on the thermometer
Correct TechniqueChapter bulb to make it easier to put in the baby's
anus.
1. Clinical thermometer
(d) Lay the baby down and the lift the feet.
(a) Make sure the temperature of the (e) Enter the thermometer into the baby's anus
thermometer is below 35°C before use.
about 1.5 cm to 2.5 cm.
(b) Shake the thermometer if the temperature
Figure 3.2  Measuring the temperature of a baby
3 is over 35°C. using a rectal thermometer
(c) Place the thermometer below armpits or
under the tongue for about 2 to 3 minutes. (f) Allow the thermometer to remain there
until a 'beep' sound is heard.
(d) Remove the thermometer and take the
temperature readings. (g) Record the temperature.
(h) Clean the rectal thermometer using alcohol
2. Laboratory thermometer
and keep it.
(a) Laboratory thermometer is not suitable to 4. Infrared thermometer
measure body temperature because it does (a) Aim the thermometer at a distance of
not have the kink in the mercury column,
as on the clinical thermometer. about 5 cm from the individual whose
temperature is to be taken.
(b) The kink is intended to prevent mercury (b) Take the temperature reading.
from go down quickly, allowing for a more
accurate reading to be taken.

(c) Temperature readings will decrease rapidly
when the laboratory thermometer is
removed from the body and cause readings
of body temperature to be inaccurate.

Kink -10 0
is not 35 36
found
Kink

Laboratory Clinical Figure 3.3  How to use the infrared thermometer
thermometer thermometer
Interpreting Body Temperature
Figure 3.1  Laboratory thermometer and
Clinical thermometer 1. The normal human body temperature is 36.9°C.

3. Rectal thermometer 2. Normal temperature estimation is in the range
of 36.5°C − 37.2°C. The temperature starts to
(a) Rectal thermometer is used to take accurate drop to normal when the temperature is not
reading of body temperature for infants within the temperature range.
aged 3 years and below.

(b) First, clean the bulb of thermometer using
alcohol to avoid infection. Then, rinse with
water at room temperature.

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Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

3. A newborn has an unstable body temperature cause dehydration and damage the organs
because his body temperature control including the brain. If not treated properly, this
mechanism is still being developed. Senior situation will endanger lives.
citizens are also less capable of controlling the
body's temperature making their temperature Table 3.2  Differences between fever and hyperthermia
unstable. Chapter
Fever Chapter
4. Body temperature also varies by gender. Hyperthermia
Hormone secretion during the menstrual cycle Body Beyond normal Normal
causes female body temperature to change and temperature
fluctuate throughout the menstruation cycle. setting point Non-functional 3
Negative (Heat
5. There are several factors that cause body Temperature Normal stroke)
temperature being higher than normal, control
including: Cooling of the
The role of Positive whole body
(a) Infections – infections of bacteria or microorganisms (infection)
viruses will activate the body's immune
system. As a result of activation of the and negative
immune system, a kind of biochemical (inflammation
material produced inside the body causes not caused by
the body temperature to rise above normal. infection)

(b) Extreme surrounding temperature – Treatment Medicines such
exposure to extreme hot conditions like as paracetamol
heat stroke and extreme sunburn causing and aspirin
body temperature to rise.
Checkpoint 3.1
(c) Physical stress and physical activity –
physical activity such as heavy workouts Q1 What does body temperature mean?
and stress increase the body's metabolic
rate, thus increasing body temperature. Q2 State four types of thermometers and their
functions.
6. If a person's body temperature exceeds the
normal temperature, the individual will be Q3 State two factors that cause body temperature
suspected of having a fever. to exceed the normal temperature.

7. If a baby less than 6 months has body 3.2 Pulse Rate
temperature above normal, the baby needs to
be taken to the hospital immediately as the Pulse Points on the Body
baby may have bacterial or viral infections.
1. Pulse is the measurement of the number of
8. Body temperature can also be less than normal. heart beats per minute.
This low body temperature is also called
hypothermia. Hypothermia occurs when 2. Pulse point is a specific area or point where
the temperature of an individual is less than the pulse can be felt, and is counted.
35°C. This condition occurs due to exposure
to extreme cold or falling into very cold water. 3. At the pulse point, the blood vessels are close
This situation can be fatal. to the layer under the skin.

9. Temperatures can also rise up to 40°C. At 4. When the heart is beating, blood will be sent
this temperature, an individual is said to have through the blood vessels and pressure in the
hyperthermia. The situation is different than bloodstream can be felt through the skin.
fever. The temperature is too high due to
system failure of the body to regulate body 5. There are several points of pulse in the body
temperature effectively. This condition can that can be felt.

6. The doctor will usually take the pulse reading
at the wrist because it is clear, prominent and
easy.

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  Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

7. Figure 3.4 shows the pulse points in the human body.

1
2
Chapter
Chapter

33

4
5

6

7

8
Figure 3.4  The pulse points in the human body

8. Figure 3.5 shows some factors that affect the pulse rate.
Factors affecting pulse rate

Gender Age Physical Activity

Females have a higher As you get older, your Physical activity such as
pulse rate than males pulse rate goes down heavy workout will result in
higher pulse rates

Figure 3.5 Factors that affect the pulse rate

9. Athletes typically have lower pulse rates than non-athletes at rest because the athlete's cardiac muscles
are stronger than non-athletes.

10. Unhealthy individuals also have a higher pulse rate compared to healthy individuals.

EEkxsppeerrimimeennt 32.1

A   Human pulse rate based on gender
Aim: To investigate the human pulse rate based on gender.
Problem statement: Does the human pulse rates differ according to gender?
Hypothesis: Women have a higher pulse rate than men.

26

Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health Chapter
Chapter
Variables:
• manipulated: Gender of students 3
• responding: Pulse rate
• constant: Time period, age and physical activity

Apparatus: Stopwatch
Procedure:
1. This activity is carried out in pairs.
2. The pulse of the male student is taken in 60 seconds as shown in Figure 3.6. The stopwatch is held by the

partner to record the time.
3. The pulse readings are recorded three times for each individual to get an accurate reading.
4. Steps 2 and 3 are repeated on the female student pairs.
(Note: Make sure students are at rest.)

Figure 3.6

Result: Pulse rate (bpm)

Gender of Reading 1 Reading 2 Reading 3 Average
students (Student's answer)

Male
Female

Discussion: Female pulse rate is higher. This is because the size of the female heart is smaller, so the female heart
has to pump blood at a higher rate than the male heart.

Conclusion: Female pulse rate is higher than that of males. The hypothesis is accepted.

B   Human pulse rate based on age
Aim: To investigate the human pulse rate based on age.
Problem statement: Does the human pulse rate differ according to age?
Hypothesis: The older a person is, the lower his pulse rate.
Variables:
• manipulated: Age
• responding: Pulse rate
• constant: Time period, gender and physical activity
Apparatus: Stopwatch

27

  Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

Procedure:

1. This activity is carried out in pairs.
2. A student's pulse is taken in 60 seconds. The stopwatch is held by the partner to record time.
3. Pulse readings. Record pulse readings three times to get an accurate reading.
4. Steps 2 and 3 are repeated for the teacher / lab assistant. (Note: Make sure the gender of the teacher / lab

assistant is the same as the student whose pulse reading is being taken and everyone is at rest.)
Chapter
Chapter
Result:
Age Pulse rate (bpm)
3 (year)
Reading 1 Reading 2 Reading 3 Average
Sample

Student

Teacher (Student's answer)

Lab assistant

Discussion: Students’ pulse rates are higher than the teacher’s / laboratory assistant’s pulse rate. This is because
students are more active and fit.
Conclusion: The pulse rate is slower as it grows. The hypothesis is accepted.

C   Human pulse rate based on physical activity

Aim: To investigate the human pulse rate based on physical activity.

Problem statement: Does the human pulse rate differ according to the type of physical activity?

Hypothesis: The more active the physical activity, the higher the pulse rate.

Variables:
• manipulated: Physical activity
• responding: Pulse rate
• constant: Time period, gender and age

Apparatus: S topwatch

Procedure:
1. This activity is carried out in groups.
(Note: Make sure members of the group are of the same gender.)
2. One of the students in the group was asked to rest, walk and run. Each activity takes 10 minutes.
3. The student's pulse count is taken after completing each activity and the reading is recorded in the table.

Result:

Group Students’ name At rest Pulse rate (bpm) Running
Walking

1 Student 1

2 Student 2 (Student's answer)

3 Student 3

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Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

Discussion: When doing vigorous activities such as running, the pulse rate will increase; this is because the
amount of energy needed is increased. Therefore, the heart pumps faster, sending oxygenated blood to the body
cells.
Conclusion: The more active your physical activity is, the higher your pulse rate. The hypothesis is accepted.
Chapter
Checkpoint Chapter
3.2
3
Q1 What is the pulse rate?

Q2 Why do doctors always check the pulse on their patients' wrist?

Q3 Natasha and Rajesh are confused when their pulse readings are not the same. Do all individuals have pulse
readings that are different like fingerprints? Justify your answer.

Q4 What is a pulse reading? What is the difference between individuals with low heart rate and individuals with
high heart rate?

3.3 Blood Pressure 4. The best instrument based on the correct
standard for measuring blood pressure
Blood Pressure Measuring Instrument readings is the sphygmomanometer used by
hospital practitioners and clinics used with
1. Blood pressure is the pressure applied by stethoscopes.
the blood on the artery wall during blood
circulation. 5. However, for home monitoring, the use of a
digital sphygmomanometer is easier.
2. The instrument used to check blood pressure
is the sphygmomanometer. 6. Diagram 3.7 shows an instrument used to
measure blood pressure.
3. The unit for measuring blood pressure is
mercury millimeters and the symbol is
mmHg.

Digital sphygmomanometer Sphygmomanometer analogue

Figure 3.7  Instrument used to measure blood pressure

Measuring and Recording Blood Pressure 2. The top number shows the pressure on the
artery during the contraction of the heart
1. Blood pressure measurements are taken muscle.
with two measurements, the top and bottom
numbers. 3. This measured pressure is called systolic
pressure.

29

  Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

4. The bottom number shows blood pressure 120 / 80 mmHg Blood pressure
during the heart muscle relaxation (between unit
heartbeats). This pressure is called diastolic.
Chapter Systolic Diastolic
5. Blood pressure measurements are recorded asChapter pressure
systolic per diastolic and measured in units of pressure
mercury millimeters (mmHg).
Figure 3.8  Blood pressure reading
3 Blood Pressure Reading
1. All individuals need to periodically check their 2. Normal blood pressure is 120/80 mmHg.
blood pressure to be aware of their health.
Early treatment must be done if blood pressure 3. Table 3.3 below shows the classifications of
readings are outside the normal range. blood pressure readings for adults.

Table 3.3  Classification of Blood Pressure readings

Blood pressure category Systolic pressure (mmHg) Diastolic pressure (mmHg)

Optimal Less than 120 Less than 80

Normal 120 – 129 80 – 84

At risk 130 – 139 85 – 89

High blood pressure stage 1 140 – 159 90 – 99

High blood pressure stage 2 160 – 179 100 – 109

High blood pressure stage 3 180 and above 110 and above

High and prolonged blood Low and prolonged blood
pressure readings pressure readings

High blood pressure Low blood pressure
• Dizziness and nausea
• Does not show obvious • Easy to faint and weak
symptoms

• If left unchecked, it can cause
heart disease and stroke

Figure 3.9  Measurement of blood pressure and its interpretation 3.3

Checkpoint

Q1 What does blood pressure mean?
Q2 What is the tool used to measure blood pressure?
Q3 What is the normal blood pressure reading for a normal person?
Q4 How can you keep your blood pressure at a normal condition?

30

Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

3.4 Body Mass Index (BMI) Table 3.4  Body Mass Index chart

Calculating and Determining Body Mass BMI (kg m-2) Category
Index
<18.5 Underweight
1. Body Mass Index (BMI) is the measurement
of body mass against height. 18.5 – 24.9 Desirable weight Chapter
Chapter
2. The Body Mass Index can be calculated using 25.0 – 29.9 Overweight
the following formula:
≥30.0 Obese

7. Table 3.5 shows the factors that cause changes 3
in body mass.

Table 3.5  Factors that cause increase or decrease in
body mass.

Low body mass Excessive body mass

3. Body Mass Index (BMI) is one way of (a) Diseases such as (a) Consume high-calorie
determining whether an individual is cancer, tuberculosis diet (more than your
experiencing body mass problems. and metabolic body needs)
diseases
4. After obtaining the BMI results, the BMI (b) Consume sweet or oily
chart can be used as a reference to determine (b) Anorexia or bulimia snacks
the individual group, whether excessive body
mass, normal or low body mass. (c) Depression and stress (c) Lack of physical
activities such as
5. Usually, BMI charts vary by gender and age. (d) Side effects of taking exercise
certain drugs
6. Table 3.4 shows the general BMI chart. (d) Genetics

(e) Metabolic diseases
such as Cushing's
syndrome

(f) Stress and poor quality
of sleep

Interpreting Body Mass Index

Low body mass can increase Excessive body mass
your risk for heart problems, increases the risk of some
causing weakness in your diseases such as heart attack,
immune system against high blood pressure, stroke,
illness, fatigue, anemia, diabetes mellitus, joint and
depression and so on. bone complications and so on.

Ideal body mass can be maintained through healthy eating and
consistent physical activity, thus reducing the risk of these diseases.

Figure 3.10  Interpretation of the Body Mass Index

31

  Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

Increase your body mass in a healthy way Reduce your body mass in a healthy way

Chapter• P ractising a healthy and balanced diet based • Set realistic goals and mass records once a week
Chapter on the Malaysian Food Pyramid and Malaysian
Healthy Plate • P racticing a healthy and balanced diet based
on the Malaysian Food Pyramid and Malaysian
• Eat meals at a regular time Healthy Plate

3 • Take snacks that contain nutrients to increase • Make some changes in your diet such as changing
the preparation of meals
calories

• Eat more nutritious foods • Reduce or avoid foods that are high in sugar and
fat

• C onsult your doctor or dietitian on how to • M oderate exercise such as brisk walking and

increase your body mass in a healthy way cycling

Fat, salt and oil • Get support from close people such as friends or
Eat sparingly family members

Protein • Consult your doctor or dietitian on how to reduce
Eat moderately your body mass in a healthy way

Fiber Malaat ayndslegiuamnes Healthy Plate
Eat plenty
Fruits

Fish, poultry, me

Carbohydrate Ricep, nroodoudclets, andbrteuabde, rcsereals, Vegetables
Eat adequately

Figure 3.11  Malaysian Food Pyramid

Figure 3.12  Malaysian Healthy Plate

Checkpoint 3.4

Q1 What does Body Mass Index mean?

Q2 What are the risks of diseases that you may encounter if you have a low body mass?

Q3 Complete the statement below.

Individuals who are and help individuals to achieve an ideal body
mass.

32

Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

CONCEPT MAP Chapter
Chapter
Techniques of Measuring the Parameters of Body Health
3

33

  Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

SPM Practice 3

Objective Questions
Chapter
Chapter 4. Why is a laboratory C The pulse rate of an
1. What is a normal body thermometer not suitable office worker is faster
temperature? for measuring body than that of a gardener
temperature?
3 A 35.9°C A Laboratory thermometer D The pulse rate of an
B 36.9°C is too long athlete is lower than that
C 37.9°C B Laboratory thermometer of a non-athlete
D 38.9°C breaks easily
C Laboratory thermometer 8. Which of the following is
2. What is the importance of has no kink the unit to measure blood
normal body temperature? D Laboratory thermometer pressure?
A Makes our body healthy is difficult to operate A Mercury millimetres
B Prevents us from a B Mercury metres
dangerous cancer attack 5. Which of the following is a C Mercury kilometres
C Ensures that our body factor that causes the body D Mercury nanometer
functions at optimal temperature to rise above
levels normal? 9. In blood pressure readings,
D Ensures our body is not A Eat spicy food the top number shows the
injured B Fatigue pressure applied on the
C Bacterial infections blood vessel wall during
3. Which of the following is the D Lack of sleep heart muscle contraction.
right step when using the What is this number?
clinical thermometer? 6. Body temperature can also A Systolic
A Make sure the be less than normal. Which B Diastolic
thermometer temperature of the following may occur if C Sistertolic
is below 35°C before use body temperature is low? D Duostalic
B Put the thermometer on A Excessive sweating
the forehead B Death 10. What is the Body Mass
C The thermometer should C Dry and bluish lips Index?
be on for about 10 D Lack of appetite A Height against mass
minutes on any part of B Body mass against
the body 7. Which of the following height
D When taking temperature statements is true of the rate C Weight against height
readings, make sure the of human pulse at rest? D Height divided by weight
thermometer is waved A Female's pulse rate is
until the temperature lower than that of a male
readings decrease B The heart rate of a
healthy person is faster
than that of a patient

34

Science Form 4  Chapter 3  Techniques of Measuring the Parameters of Body Health

Subjective Questions
Section A

1. A student conducted an experiment to investigate the temperature of a liquid. Figure 1 shows the temperature
reading of the thermometer.
Chapter
Chapter
40 50 60 70

3

30 40 50 60



Reading 1 Reading 2 Reading 3 Reading 4

Figure 1 [2 marks]
[1 mark]
(a) Record all four temperature readings. [1 mark]
[1 mark]
(b) In your opinion, what type of thermometer is used in the above experiment?

(c) Predict the temperature of reading 5 if heating is continued.

(d) Mark (3) on the use of this type of thermometer.

(i) Measure temperature of liquids
(ii) Measure body weight
(iii) Measure body temperature

2.
When your body temperature is above 37°C, you are suspected of having a fever. Body temperature can
also be lower than normal if you are exposed to extreme cold. This condition can be fatal too!

(a) Based on the above statement, state the three factors that can cause an increase in body temperature.
[3 marks]


(b) What is the normal body temperature? [1 mark]

(c) What type of thermometer is suitable for measuring a baby's body temperature? [1 mark]

Section B
3. Excessive weight is a serious health issue and can cause a variety of chronic diseases.

(a) List two chronic diseases that can occur if you have an excessive weight problem. [2 marks]

(b) Daniel is overweight. If you were his nutritionist, what advice would you give to him? [2 marks]


(c) What is the Body Mass Index? How can we keep our body mass in an ideal weight category?
[2 marks]


35

1Chapter Safety Measures in the that involve chemicals that Checkpoint 2.2
Laboratory are volatile, flammable,
poisonous, corrosive and Q1 Heimlich Manoeuvre is an emergency
Checkpoint 1.1 smelly. procedure that is carried out to save
(b) Eyewash station. He needs to an individual who is choking, due to
Q1 The school laboratory has various wear goggles so that chemical something (for example food) being
chemicals that are dangerous and spills will not get into his eyes. stuck in the trachea.
glassware that are fragile.
3. (a) (i) Cannot Q2 An individual needs Heimlich
Q2 goggles, face mask, gloves, lab coat, Manoeuvre if found:
long pant and closed shoes. (ii) Hydrochloric acid is a strong
acid and can corrode the (a) holding his neck with both hands
Checkpoint 1.2 piping system in the sink. suddenly
Hydrochloric acid will also
Q1 Acid, grease, oils pollute the river if disposed (b) unable to talk or cough
of into the sink. (c) skin, lips and nails suddenly
Q2 Obey laboratory rules, carry out
activities and experiments carefully (b) (i) Liquid biological waste need bluish or darkens
and mindfully. to be decontaminated by (d) difficulty breathing
autoclave. Then, the liquid
Q3 Sharp tools, non-sharp solids, waste can be disposed of Q3 Food that enters the breathing
carcasses and body fluids directly into the sewage passage will prevent oxygen from
system through the entering the lungs and hence cannot
Q4 To remove any biological agents that laboratory sink. be sent to the brain. Heimlich
are dangerous on sample such as Manoeuvre is important to ensure
bacteria or fungus before disposing it (ii) Blood and serum victim that is choked does not
into the environment. undergo brain damage or death.
(iii) His experimental waste is
Q5 Inform the teacher or laboratory a frog carcass. Carcass Q4 Can. Heimlich Manoeuvre can
assistant. need to be wrapped with be self-administered by applying
an absorbent material, in pressure by bending the body over a
Checkpoint 1.3 a biohazard plastic bag chair or a table and pushing the body
and frozen. The bag must against the chair or table.
Q1 Fuel, oxygen and heat be kept in a safe place
at freezing temperature SPM Practice 2
Q2 Water, foam, carbon dioxide and dry such as a cold room until
powder it is disposed by a chosen Objective Questions
contractor.
Q3 • Not harmful to human and animals 1. D 2. B 3. C 4. B 5. A
• Do not pollute the soil
6. D 7. B 8. A 9. C 10. C

SPM Practice 1 2Chapter Subjective Questions

Objective Questions Emergency Help 1. (a) Cardiopulmonary resuscitation
(CPR) method
1. B 2. D 3. A 4. C 5. D
(b) (i) Victim did not respond or
6. B 7. C 8. A 9. D 10. B Checkpoint 2.1 react

Subjective Questions Q1 CPR is an emergency help that is (ii) Victim has no pulse beat
carried out to restore heartbeat and
1. (a) Did not use personal protective breathing of victims facing heart and (c) Compressing the chest will
equipment breathing problems. induce blood circulation by
pumping blood through the
(b) Gloves and lab coats Q2 Situations that requires CPR: heart. This method is important
(a) not breathing to ensure the continuous
(c) Chemicals tested and solid (b) no pulse beat circulation of blood in the body
wastes form in mixtures (c) do not respond to stimulus of victim. This way oxygen can
be carried to all parts of the
2. (a) (i) Laminar flow cabinet and Q3 CPR is important to ensure the flow body and the brain to save the
fume chamber. of blood throughout whole body of victim.
the victim. CPR is also important to
(ii) • L aminar flow cabinet ensure continuous supply of oxygen 2. (a) Heimlich Manoeuvre method
is used to prevent to the victim’s brain to avoid brain
contamination during damage. (b) Choking victim
activities involving
microbiology. (c) Victim will lack oxygen causing
brain damage and death.
• F ume chamber is used
to carry out experiments (d) Chair or table

(e) Bring victim to hospital for further
treatment.

203

  Science Form 4  Answers

3Chapter Techniques of Measuring • Frequently monitor at home using a forestry sector, transportation sector
the Parameters of Body digital sphygmomanometer.
Health Checkpoint 4.2
Checkpoint 3.4
Checkpoint 3.1 Q1 (a) Increase in the use of fossil fuels
Q1 Body Mass Index (BMI) is the (b) Extreme climate change
Q1 Body temperature is the degree of measurement of body mass against (c) Production of greenhouse gases
hotness and coldness of body. height.
which cause global warming
Q2 Q2 Reduce body mass can increase
risks of heart problem, body Q2 Hydro and solar energy. Malaysia is a
Type of Function immunity, anaemia, depression and tropical country with plenty of natural
thermometers others. water reserves. Apart from that,
Malaysia is situated at the equator
Clinical Used to measure body Q3. Practise healthy eating, do consistent and receives enough sunshine the
physical activity (accept other suitable whole year round.
thermometer temperature answers)
Q3 Geothermal energy has many
Laboratory Used to measure limitations and depends on
several factors especially suitable
thermometer temperature of liquids SPM Practice 3 geographical factor.

Rectal Used to measure body Objective Questions Checkpoint 2.3
thermometer temperature of babies
through their anus 1. B 2. C 3. A 4. C 5. C Q1 (a) Sewage and rubbish disposed
of into the river pollute our water
6. B 7. D 8. A 9. A 10. B source and threaten aquatic life.

Infrared Used to measure body Subjective Questions (b) Generation, management and
thermometer temperature without breakdown of solid wastes
having any contact with 1. (a) Reading 1: 35ºC contribute towards the production
the body of greenhouse gases.
Reading 2: 44ºC
Q3 Bacterial infection and exposure to Q2 (a) Application of 5R
extreme heat. Reading 3: 54ºC (b) Carry out treatment and

Checkpoint 3.2 Reading 4: 72ºC processing of solid wastes.
(b) Laboratory thermometer
Q1 Pulse rate is the measure of number (c) 100ºC Checkpoint 4.4
of heart beats per minute.
(d) (i) Measure temperature of Q1 Excessive use of chemical fertilisers
Q2 Wrist is where the pulse beat is clear, liquids will affect the pH of soil and causes
exposed and easy. it to be unsuitable for agriculture.
2. (a) Bacterial infection, virus infection Excess chemical fertilisers will enter
Q3 No. Pulse rate is not like finger prints. and inflammation of joints the rivers and pollute the water
Pulse rate of everyone may be the source.
same or different based on factors (b) 36.9ºC
like gender, age and physical activity. (c) Rectal thermometer Q2 (a) Control logging activities by
A finger print of everyone differs since gazetting more areas as reserve
birth. 3. (a) Heart attack, high blood forest.
pressure
Q4 Pulse beat is the pressure felt when (b) Replanting of trees
blood is pumped by the heart and (b) Change diet and do light
flow through blood vessel near the exercises at least three times Checkpoint 4.5
surface of the skin. Pulse rate differs per week.
according to factors like gender, age Q1 Greenhouse effect and formation of
and physical activity. (c) Ideal Body Mass Index is 18.5 acid rain
to 24.9. Ideal body mass can be
Gender: Females have higher pulse maintained by a healthy diet and Q2 (a) Green transportation is introduced
rate than males. consistent physical activity. to minimise the release of
greenhouse gases
Age: Pulse rate decrease with aging. 4Chapter Green Technology
Physical activity: Vigorous activity for Environmental (b) Invention of natural gas for
Sustainability vehicles which does not use
increases the pulse rate. petroleum as fuels.
Checkpoint 4.1
Checkpoint 3.3 Checkpoint 4.6
Q1 Green technology is the development
Q1 Blood pressure is the pressure and application of products, Q1 (a) Practise recycling by separating
applied by the blood on the artery equipment and systems used your rubbish.
during blood circulation when blood conserve the environment and
is pumped by heart to the rest of the nature, as well as minimising and (b) Save electricity by switching off
body. reducing the negative effects of electrical appliances that are not
human activities. in use.
Q2 Sphygmomanometer
Q2 (a) energy conservation can be
Q3 120/80 mmHg increased
Q4 • Practise a healthy lifestyle, a
(b) the county’s economy will be
balanced diet and do exercises. strengthened

Q3 Energy sector, waste and wastewater
management sector, agriculture and

204

Science Form 4  Answers

SPM Practice 4 Q5 Mitosis is important for cell growth. random fertilisation and mutation)
Meiosis is important for producing and environmental factors (nutrients,
Objective Questions 4. A 5. D gametes for reproduction. temperature, light and pH).
1. A 2. A 3. B 9. B 10. C
6. D 7. A 8. B Checkpoint 5.2 Q4 • Variations are important for survival
of the species through camouflage
Subjective Questions Q1 The phenotype refers to the physical to protect themselves from
traits of an organism. predators.
1. (a) Agriculture and forestry sector
(b) • Land cleared for settlement Q2 1 rounded seed plant : 1 wrinkled • Variation is also important to help a
seed plant species adapt to drastic changes in
and agriculture the environment.
• Logging for furniture and paper Q3 The father
SPM Practice 5
industry Checkpoint 5.3
(c) • Replanting of trees Objective Questions 4. B 5. C
• Treatment of agricultural waste Q1 Mutation can be divided into 1. C 2. C 3. C 9. D 10. B
chromosome mutation (Down 6. A 7. B 8. C
to produce compost syndrome, Turner syndrome,
• Enforcement and control of Klinefelter syndrome) and gene Subjective Questions
mutation (colour blindness, sickle cell 1. (a)
logging activity anaemia, thalassemia, haemophilia
2. (a) X - Service vehicles and albinism). Blood A B AB O
group
Y - Public transportation Q2 Factors that may cause mutation
Z - Bicycle (any 3): spontaneous, chemical toxic, Number of 14 5 9 7
(b) • Production of greenhouse ultraviolet ray, X-rays, radioactive residents
rays, late pregnancy
gases can be reduced, social (b)
health improved, saving of Q3 One application for genetic research
energy sources can be well is in the field of gene therapy. Number of residents
implemented. Gene therapy can be used to fix
(c) • Carbon content in air increases, mutated, damaged or abnormal 16
greenhouse effect worsens, genes. Through gene therapy, normal
global warming felt and extreme genes can be inserted into the cell 14
climate change or patient’s body tissue to replace
3. (a) W - focus on the effort to damaged genes. 12
minimise disposal of solid and
liquid waste to the environment. Checkpoint 5.4 10
Y - energy sector
(b) Energy. Green technology Q1 genetically modified organisms, 8
promotes energy efficiency and recombinant DNA technology, gene
finds alternatives so as not to be therapy 6
dependent on energy.
(c) Domestic wastes collected Q2 Recombinant DNA technology 4
can be processed to compost.
Compost as fertiliser is safer Q3 Genetically modified food contain 2
to use compared to chemical higher nutritional value and a higher
fertilisers that are commonly resistance against pests. 0 A B AB O Blood
used. group
Q4 Genetic engineering can help identify
5Chapter Genetics genetic disorders at an early stage. (c) Discontinuous variation
However, one disadvantage is that
Checkpoint 5.1 genetically modified food may carry 2. (a) (i) Female
side effects such as causing allergic
Q1 DNA is a double helix made up from reactions in individuals. (ii) The offspring has two X
a series of genes which are the chromosomes
genectic codes that determine the Checkpoint 5.5
physical traits of an individual. (b) Male
Q1 Variation is the differences in
Q2 (a) Mitosis is a process where a individuals of the same species. (c) 50%
parent cell divides into two
identical daughter cells. Q2 In continuous variation, the (d) Number of chromosomes: 44 +
differences in individuals of the same XO
(b) Meiosis is a process where species is not discretely apparent,
a parent cell divides into four for example human height. In Disorder: Turner syndrome
cells with only half the genetic discontinuous variation, variations
information the parent cell carries. come in distinct and discrete classes 3. (a) (i) Continuous variation
or groups, for example blood groups.
Q3 Crossing over (ii) Genetic factor
Q3 There are two factors that cause
Q4 Mitosis produces two diploid daughter variation, which are genetic factors (b) Skin colour is influenced
cells whereas meiosis produces two (crossing over, independent by both genetic factors and
haploid daughter cells. (Accept any assortment of chromosomes, environmental factors. Although
suitable answers) Ahmad inherited his light skin
colour from both parents, being
exposed to the hot sunny
weather for long periods of time
causes his skin colour to darken
naturally.

(c) • Variation allows a species to
adapt to drastic changes to the
surroundings.

205

  Science Form 4  Answers

• Variation enables us to easily Checkpoint 6.2 2. (a) X
differentiate and recognise
each individual in the same Q1 When the biceps contract and the
species. triceps relax at the same time, the
forearm is pulled up and the arm is
4. (a) (i) Meiosis I bent.
(ii) S, Q, T, R
Q2 • Taking a diet that is full of calcium,
(b) The chromosomes condense, phosphorus, vitamins, proteins and (b) (i) Have an endoskeleton
shorten and become visible. iron.
Chromosomes exchanged (ii) Large
genetic information through a • Adopting a good posture.
process known as crossing over. (iii) Small
Q3 The definition of growth is a
(c) When a sperm which is consistent and irreversible change (iv) Strong
haploid (carrying half of the to shape, increase in mass and size
chromosomes in the parent of an organism throughout its growth (v) Weak
cell) fertilises an ovum which is process.
also haploid, a diploid zygote is 3. (a) (i) Reading on the ruler:
produced. Q4 The human growth pattern is a 2.5 cm, 3.8 cm, 6.2 cm
sigmoid shape. Growth rates are
6Chapter highest at the infancy stage, then (ii) The plant absorbs nutrients
slowing down at the childhood stage. from the ground.
The growth rate will accelerate again
at the adolescence stage then reduce (b) (i) The growth rate of boys is
again at adulthood. Finally, growth higher than of girls.
rates turn negative in the old age
stage. (ii) The growth rate of girls is
higher than of boys.
Q5 Teenage girls have higher growth
Support, Movement and rates than boys because they reach 7Chapter
Growth puberty earlier than boys.

Body Coordination

Checkpoint 6.1 Checkpoint 6.3 Checkpoint 7.1

Q1 Three types of animal skeleton: Q1 The importance of support system in Q1 Hormones are organic chemicals
(a) Endoskeleton (example: cow) plants: substances secreted by endocrine
(b) Exoskeleton (example: prawn) glands directly into the blood
(c) Hydrostatic skeleton (example: (a) Twigs and leaves are positioned circulatory system.
for maximum exposure to
earthworm) sunlight. Q2 (a) Estrogen
(b) Adrenaline
Q2 (b) Flowers are positioned for (c) Thyroxine
pollination.
Terrestrial Aquatic Q3 (a) Lack: simple goiter;
vertebrate vertebrate (c) Seeds are placed strategically for Excessive: toxic goiter
seed dispersion.
Similarity: (b) Lack: dwarfism;
Has an endoskeleton Q2 Floating aquatic plants have large Excessive: gigantism
air sacs in roots and leaves to keep
Larger and Small and weaker the structure afloat. Aerenchyma (c) Lack: diabetes insipidus:
tissue keep the plant floating and is Excessive: headaches
stronger pelvic and pelvic and pectoral essential in gaseous exchange.
Checkpoint 7.2
pectoral girdle girdle Q3 By counting the number of growth
rings in the trunk of woody plants. Q1 (a) Tranquilisers will prevent or
Body weight Majority of the slow down nerve impulse
supported by the weight supported transmissions in body
endoskeleton by water buoyancy coordination. The user will feel
tired and at ease. Tranquiliser
Has a body size Has a body size SPM Practice includes morphine and opium.
similar to the much larger than
endoskeleton the endoskeleton (b) Stimulants will speed up impulse
transmission in body coordination.
Q3 The human skeletal system consists 6 The user will feel active, anxious
of 206 fused bones. The skeleton can and paranoid. Stimulants include
be divided into two parts, which are Objective Questions 4. B 5. C nicotine and caffeine.
appendicular skeleton and the axial 9. C 10. D
skeleton. The axial skeleton is made 1. B 2. A 3. B Q2 Hormonal imbalance - the body
up of the skull, vertebral column, 6. B 7. C 8. D experiences physical and mental
rib cage and sternum whereas the changes such as a larger body,
appendicular skeleton consists of the Subjective Questions depression, poor memory
pectoral girdle, pelvic girdle, upper 1. (a)
limbs and lower limbs. Slurred speech - the cerebrum which
Biceps is where the area in charge of speech
Q4 Centre of gravity and base area Tendon is located, is affected

Q5 Kangaroos use their tail as the (b) Strong and inelastic Q3 Cirrhosis of the heart - scarring
support system to increase the base and hardening in the liver due to
area when it is in standing position. (c) When the biceps muscle excessive consumption of alcohol
contracts, the triceps relaxes. and drugs
The pull force is transferred via
the tendon. The radius bone is
pulled upwards.

206

Science Form 4  Answers

Stomach ulcer - sores in the stomach 3. (a) Drugs are chemicals that affect (ii) Physical and mental health
membrane because of excessive the neurones by slowing down
excretion of acid when alcohol is Liver cirrhosis
consumed impulse transmissions between
neurones. Alcohol abuse can lead to
(b) Drug category: toxic effects to the liver.
Checkpoint 7.3 Cirrhosis of the liver is a
• tranquiliser - Barbiturate,
Q1 The mind is the brain function that heroine, morphine serious condition where
relates to our consciousness, such
as personality, thinking, memory, • Inhalant - Glue, gasoline, ether the liver experiences
judgement, intellect and emotion. • stimulants - amphetamine, chronic damage, scarring,

Q2 Features of a healthy mind: Can caffeine, nicotine hardening and impaired liver
think and make judgement, able
to detect stimuli, can recall past • hallucinogen - marijuana, functions.
events, dare to accept challenges, Lysergic asid diethylamide
able to differentiate between rights Hallucinations
from wrong, responsible, free from
prejudice, leads a peaceful life, open- (LSD) (choose any two) Consuming drugs like
minded, able to reason inhalants and hallucinogens
(c) Effects of drug abuse:
Q3 Drug abuse, alcohol abuse, mental • Hormonal imbalance will affect the brain and
stress • Slurred speech
• Slow reflexes change perceptions.
(or any other acceptable
8Chapter
answers) Elements and Substances

4. (a) (i) Oestrogen

SPM Practice 7 (ii) - Stimulates the Checkpoint 8.1
development of secondary
Q1 (a) high melting point
Objective Questions sex characteristics (b) positive ion

1. D 2. A 3. B 4. C 5. B - Stimulates the formation of Q2 Atom, molecule and ion
6. C 7. D 8. D 9. A 10. C ova
11. B 12. B Q3 Iron can exist as atom or ion. Iron
(b) During teenager (puberty) atoms exist in a new iron hammer.
When the iron hammer starts rusting,
(c) (i) Testes iron exist in the form of ions.

Subjective Questions (ii) Testosterone

1. (a) Pancreatic glands are important 5. (a)
to control blood glucose
concentration. Type of Action Checkpoint 8.2
drug
(b) (i) Removal of the gland Q1 Elements are arranged horizontally
Tranquiliser Stops or slows according to their increasing proton
(ii) Concentration of glucose in down nerve impulse number from left to right.
the blood transmissions in body
coordination Q2
(iii) Size of mouse
Stimulant Speeds up impulse Element Proton Electron
(c) The pancreatic gland excretes transmission in body number arrangement
insulin which controls the coordination W
concentration of glucose in X 15 2.8.5
blood, preventing diabetes Inhalants Chemicals that can Y
mellitus. be inhaled through Z 16 2.8.6
breathing can cause
2. (a) Endocrine glands are ductless hallucinations 17 2.8.7
glands, secreting hormones
straight into the blood flow Hallucinogen Change the nerve 18 2.8.8
impulse transmission
(b) Endocrine glands in the human pathways in the brain Q3 Electron arrangement P: 2.7
body include:
(b) (i) Body coordination Q4 Metal atoms will form positive ions by
• Pituitary gland donating electrons, while non-metal
• Thyroid gland Slow reflexes atoms will form negative ions by
• Testes accepting electrons.
• Ovaries Drug and alcohol abuse
• Adrenal gland can slow down the nerve
• Pancreas
(any two) system’s response towards Checkpoint 8.3
(c) Controls the sugar level in blood stimuli. Chemicals will
collect between the afferent Q1 Isotopes are atoms of an element
by converting excess glucose to with same number of protons but
glycogen. neurone and interneurone different number of neutrons. For
(d) Causes of hormonal imbalance: blocking the transmission of example, there are two types of
• Poor diet impulses. carbon atoms in a sample of carbon
• Exposure to dangerous rays element, that is carbon atom with 6
Loss of balance protons and 6 neutrons and carbon
such as radioactive rays atom with 6 protons but 8 neutrons.
• Unhealthy lifestyle Consuming drugs and So, carbon has isotopes.
(any two answers) alcohol can lead to weak
muscle coordination and the

inability to walk properly.

207

  Science Form 4  Answers

Q2 Bromine-79 Bromine-81 4. (a) (i) Proton and neutron Checkpoint 9.3
Isotope
(ii) Nucleon number is the total Q1 Natural polymers exist in living things
Number of 35 35 number of protons and in nature
protons neutrons in the atom.
Synthetic polymers are man-made
Number of 35 35 (iii) 1 electron through chemical processes
electrons
(b) (i) 17 Q2 Sulphur atoms forms cross-links
(ii) Atom L and atom J have between rubber molecules to form
vulcanised rubber.
the same number of
Number of 44 46 electrons in their outermost
neutrons shell.

Nucleon 79 81 9Chapter
number

Q3 In medicine, isotope cobalt-60 is used Chemicals in Industry
to kill cancer cells. Apart from that
isotope sodium-24 is used to detect Checkpoint 9.1 Cross-links
the location of blood clot. Isotope
iodine-131 is used to treat thyroid Q1 Duralumin Q3 Polymerisation is the process of
gland. Q2 (a) Iron and carbon joining the monomers through the
(b) Addition of carbon element in iron formation of chemical bonds to
Q4 Isotopes of an element have the same produce a long chain polymer.
number of protons. during alloying process disrupts
the orderly arrangement of atoms Depolymerisation is the process of
So, number of protons in an atom of in iron. This is because the size splitting a long chain polymer into
phosphorus-31 = 31 – 16 = 15 of carbon atoms is different from its monomers through chemical
iron atoms. Presence of carbon reactions.
So, the number of neutrons present atoms make it difficult for the
in an atom of phosphorus-32 layers of iron atoms to slide when
a force is applied.
= 32 – 15 = 17
Q3 • Superconductor alloy is used in
SPM Practice 8 making high-powered railway SPM Practice 9
tracks.
Objective Questions Objective Questions
• Superconductor alloy is also used
1. A 2. C 3. A 4. C 5. B in Magnetic Resonance Imaging 1. A 2. C 3. A 4. D 5. B
(MRI) machine.
6. D 7. A 8. C 9. B 10. B 6. D 7. A 8. D 9. B 10. B
Checkpoint 9.2
11. D 12. D 13. C 11. C 12. D
Q1 Transparent, chemically inert and
Subjective Questions easy to shape (accept other suitable Subjective Questions
answers)
1. (a) Neon 1. (a) (i) Types of metal blocks
Q2 Aluminium silicate
(b) Li / Na/ K/ Fe Q3 (a) Fused silica glass is transparent (ii) Diameter of the dent

(c) Halogens and can withstand high heat and (iii) Mass of the weight
suitable for making lenses and
(d) Chlorine/ Bromine spectacles. Lead crystal glass (b) Bronze is harder than copper.
has a high reflective index and / Alloy is harder than its pure
(d) 2.1 shiny suitable for making prism metal.
and decorative items.
2. (a) Hydrogen (b) Ceramic is a good insulator of (c) Bronze is harder than copper.
(b) R heat and suitable for making 2. (a) (i) Y: Copper
the lining in furnace. The inert Z: Zinc
(c) (i) Vertical columns in the property of ceramic towards
Modern Periodic Table of chemicals and resistant towards (b) Alloying
Elements corrosion made it suitable as
kitchenware. (c) (i) Hard
(ii) Have same chemical
properties Q4 Glass can be melted for recycling. (ii) Addition of zinc atoms
Ceramic will harden when heated to prevent the layers of copper
(d) (i) Ruthenium high temperatures. Hence, ceramic atoms from sliding over
cannot be recycled. each other easily. Thus,
(ii) Transition elements alloy is harder.

3. (a) 19 3. (a) Aluminium silicate
(b) Q (b) Advantage: Waterproof /
(c) 2.6
(d) Atom Q needs to donate one Resistant to corrosion /
Withstand high temperature
electron to achieve octet electron Disadvantage: Brittle / Cannot be
arrangement. recycled
(e) (c) Ceramic can withstand high
heat, so it does not melt easily.
Electron Glass melts easily, so it can be
Proton remoulded.
Neutron (d) Bricks and tiles



208

Science Form 4  Answers

1 0Chapter Chemicals in Medicine and Subjective Questions Checkpoint 11.3
Health
1. (a) (i) Aspirin Q1 Acceleration due to gravity is the
Checkpoint 10.1 acceleration that occurs in the Earth’s
(ii) To kill or to prevent gravitational field.
Q1 1. Analgesics: Aspirin, paracetamol reproduction of bacteria
2. Antibiotics: Penicillin, Q2 Object in free fall means object is
(iii) To treat psychiatric patients falling with only gravitational force
streptomycin acting on it.
3. Psychotherapeutic: (b) (i) Aspirin
Q3 (a) False
Antidepressant, stimulants (ii) Not suitable. Aspirin is (b) False
acidic and can cause
Q2 Complementary methods are natural internal haemorrhage // Checkpoint 11.4
methods and ensure that the patient swollen pancreas // liver
is holistically, physically, mentally failure // skin rashes for Q1 Inertia is defined as the tendency
and emotionally healthy. This method children. of an object to maintain its state,
does not involve the use of medicines whether at rest or in motion with
or surgery. 2. (a) Traditional medicines are uniform velocity. We also define
derived from plants and animals. inertia as the resistance of an object
Q3 Effects include patient not recovering, Modern medicines are made by to change in its state of rest or
addiction problem and problem with scientists in the laboratory based motion with uniform velocity.
resistant bacteria. on the active ingredient in the
natural substances. Q2 – When a car in motion suddenly
Checkpoint 10.2 stops, all the passengers are
(b) thrown forward.
Q1 Free radicals are atoms or molecules
that lack one electron which makes Traditional Function – When the lift starts to descend, we
the atoms or molecules unstable, medicine seem to be left hanging in space.
reactive and tend to attack other
atoms or molecules. Tongkat Lowers body temperature Q3 The larger the mass of an object, the
Ali of patient with high fevers greater its inertia.
Q2 Effects include cancer, cardiovascular
diseases, internal organ failure and Aloe vera Heal skin wounds / reduce
premature aging. swelling

Checkpoint 10.3 1 1Chapter SPM Practice 11

Q1 Antioxidants are chemical compounds Force and Motion Objective Questions
that are needed by the body to
slow down or to stop the oxidation 1. B 2. B 3. D 4. B 5. D
process.
6. C 7. A 8. B 9. A 10. C
Q2 Antioxidants stabilises the free
radicals by providing them the Checkpoint 11.1 11. C
missing electron and help stop the
chain reaction from forming free Q1 Distance is the total path length Subjective Questions
radicals. travelled by an object, whereas
displacement is the distance of the 1. (a) Rate of change of velocity
Q3 Oxidation of food takes place when shortest path that connects two 4.5
food is exposed to air. locations in a specified direction. (b) u = (5 x 0.02)

Checkpoint 10.4 Displacements = 45 cm s-1
Time
Q1 Active ingredients are active chemical Q2 Velocity = v = 22.5
compounds that have effects on (5 x 0.02)
the body system in diagnosis, cure,
treatment or prevention of disease. = 100 m = 225 cm s-1
9.58 seconds
Q2 Many people take health products to v–u
maintain their health. An increasingly = 10.44 m s-1 a = T
hectic lifestyle and lack of a balanced =
diet caused certain people need Q3 Acceleration = Changing in velocity 225 – 45
health products to guarantee health. Time taken 2 x 0.1

= (8 m s-1 – 0 m s-1) = 900 cm s-2
10 s = 9.0 m s-2

= 0.8 m s-2 (c) Air resistance and friction
between ticker tape and ticker
Checkpoint 11.2 timer.

Q1 (a) velocity 2. (a) Velocity is defined as the rate
(b) acceleration of change of displacement for a
motion.
Q2 In the velocity-time graph,
SPM Practice 10 displacement is obtained by (b) The car experiences
calculating the area under the graph. deceleration/negative
Objective Questions acceleration.

1. D 2. C 3. A 4. C 5. A

6. D 7. D 8. B 9. C 10. C

209

  Science Form 4  Answers

(c) • To kill cancer cells Subjective Questions
Velocity (m s–1) • To detect leakage from
1. (a) The process of splitting a heavy
underground pipes radioactive nucleus into two
new nuclei which are lighter and
Q2 Nuclear energy is an electrical more stable with the release of
energy source that is cleaner and nuclear energy.
more efficient because coal and
Time (s) natural gas will cause wastage and (b) • Nuclear fission reaction
pollution during the combustion produces two or three new
(d) Acceleration process. neutrons.

= Changing in velocity Q3 • Harmful to health of the residence • These neutrons collide with
Time taken in the long term. other uranium nuclei, causing
the nuclei to split to produce
• Risk of nuclear accident when more neutrons.
reactor is in operation.
• Continuous fission will occur
Checkpoint 12.2 if at least one neutron splits
another uranium nucleus.
Q1 Nuclear fission and nuclear fusion
= Final velocity(v) – Initial velocity (u) (c) So that it is more light and
Time taken (t) Q2 Nuclear fission stable.
Q3 • Lack of energy sources
= (0 m s-1 – 20 m s-1) • Very high energy demand (d) Containment structure - prevents
5s leakage of radioactive radiation
Checkpoint 12.3
= -20 m s-1 from reactor core
5s Q1 Two Japanese cities (Hiroshima and 2. (a) X - uranium fuel rods
Nagasaki) destroyed, many civilians
= -4 m s-2 killed. Buildings collapsed and (b) Release heat energy through
burned. nuclear fission to heat up gas

Q2 • Destroys marine ecosystem flowing through reactor
• Land is polluted and unsafe for
3. (a) Inertia is the natural tendency of (c) • Concrete shield
an object to resist any change to habitation • Boron control rods
its original state, whether at rest
or in motion. Q3 Exposure to radioactive radiation (d) • Land polluted by radiation and
will cause humans to suffer from unsafe for habitation
(b) An object will remain in its original somatic and genetic effects. Somatic
state, whether at rest or in motion effects include fatigue, cataract and • Cause somatic and genetic
hair loss. Genetic effects include effects on humans
with uniform velocity in a straight deformed offspring, cell mutation and
cancer. 3. (a) The process of combining two
line if no external force acts on it. light radioactive nuclei to form a
(c) Bucket P is easier to push than Checkpoint 12.4 heavier nucleus with the release
of energy
bucket Q. /Bucket P stops first Q1 • Dwindling reserves of fossil fuels
followed by bucket Q. encourage the construction of (b) Similarity - Both produce huge
(d) Bucket P has a smaller mass nuclear power plants. amounts of energy.
than bucket Q. Therefore, bucket
P has smaller inertia than bucket • Nuclear power plants do not Difference - Nuclear fission
Q. produce air pollutants, therefore air produces two new nuclei that are
pollution and greenhouse effect will lighter and more stable; nuclear
(e) The larger the mass of an not occur. fusion produces a heavier and
object, the greater its inertia. more stable atom.
Q2 • Nuclear power plants produce
radioactive waste that is harmful (c) Generate electricity
to the environment and living
4. (a) The toy car moves with uniform organisms. (d) • Destroy marine ecosystem
velocity because the distances • Propagation of radioactive
between any two consecutive • Cost of constructing nuclear power
dots on the tape are the same. plants and managing radioactive radiation to environment and
waste is very high. living organisms

(b) (i) Time between two dots Q3 Student’s answer 4. (a) Nuclear fission

= 1 ÷ 50 s = 0.02 s (b) Nuclear energy
Time taken to move from M
to N (c) Fission process is allowed to
occur continuously at a uniform
= 0.02 s x 5 = 0.1 s
rate under controlled conditions.

(ii) Velocity of toy car Nuclear energy released is used
to heat up water to become
= 10 cm ÷ 0.1 s = 100 m s-2 steam. Steam is used to rotate
the turbine of the electric
(c) Zero (no acceleration) generator.

(d)

Direction of motion (d) Produce radioisotope materials

1 2Chapter 5. (a) Nuclear fission

SPM Practice 12 (b) (i) Boil water to produce steam

Nuclear Energy (ii) Rotate turbine

Objective Questions (iii) Generate electricity

Checkpoint 12.1 1. C 2. C 3. D 4. A 5. D (c) (i) Neutron

Q1 • To kill bacteria for the purpose of 6. C 7. C 8. A 9. C 10. C (ii) Uranium-235
sterilising medical equipment

210

Science Form 4  Answers

PRE-SPM MODEL PAPER (b) 8. (a) • Protect internal organs
• Enable movement
Paper 1 3. C 4. A 5. B Continuous variation Mass(kg) (b) • Stretch both legs
1. C 2. A 8. D 9. C 10. B • Increase base area
6. C 7. D 13. B 14. A 15. C 14 (c) • Caterpillars have a hydrostatic
11. D 12. C 18. C 19. A 20. A 12
16. D 17. A 23. C 24. B 25. D 10 skeleton.
21. A 22. C 28. C 29. D 30. A
26. A 27. B 33. C 34. A 35. B 8 • Centipede has an exoskeleton.
31. A 32. B 38. D 39. A 40. B 6 9. (a) Traditional medicine can be
36. B 37. C 43. D 44. B 45. A 4
41. C 42. B 48. A 49. B 50. D 2 derived from plants and animals.
46. B 47. D 0 Modern medicine is produced by
40-44 scientists in the laboratory based
45-49 on active ingredients in natural
50-54 substances.
55-59
60-64 (b)

Paper 2 (c) Continuous variation Traditional Disease Method
Section A medicine
1. (a) 4. (a) Latex coagulates in formic acid
// Latex does not coagulate in Garlic Lowers blood Eat // Use
Height (cm) ammonia solution / no change. pressure // in cooking
Treat asthma/
25 Bright area (b) When formic acid is added flu
Dark area into latex, coagulation occurs.
// When ammonia solution is
20 added into latex, coagulation Aloe vera Treat cuts Apply on
does not occur. on the skin target area
// Reduce
15 (c) (i) Coagulation occurs. swelling
(ii) Bacteria in the air produces
10 Ginseng Treat sexual Drink its
acid when they reproduce; dysfunction boiled
5 the acid coagulates the in men // extract
latex. antioxidant
0 Time (d) Acid is the substance added to
12345 6 (days) latex for coagulation.

(b) Height of green bean seedlings Section B (c) • Follow the dose given and
increase with each passing day 5. (a) (i) Thyroid finish up the antibiotics
(ii) Increase metabolism rate //
(c) 23 cm – 30 cm • If the antibiotic is not fully
Cause goitre consumed, the remaining
2. (a) The iron nail has become bacteria may develop a
corroded whereas the steel nail (b) (i) Insulin resistance against the
has no changes. // There is (ii) Controls blood glucose antibiotic.
brown precipitation on the iron
nail while the steel nail has no levels Section C
changes.
(c) (i) An excess in growth 10. (a) The larger the mass, the longer
(b) (i) Manipulated variables: Iron hormones it takes for the object to come to
nail and steel nail / Types of a stop.
nails (ii) Pituitary
6. (a) (i) 36.9°C (b) (i) Aim: To study the effect
(ii) Constant variables: (ii) A: Mercury thermometer mass has on time required
Distilled water / Duration of B: Digital thermometer for an object to come to a
experiment (iii) Rectal thermometer stop.
(b) (i) Infrared thermometer
(c) An alloy is a mixture of several (ii) By pointing the infrared (ii) Manipulated variable: The
types of metals or a mixture of mass of object
metal and non-metal by a certain thermometer at the
percentage. forehead Responding variable: Time
taken for the object to come
(d) Steel iron is more resistant 7. (a) (i) Ozone to a stop
against corrosion than an iron (ii) Absorb ultraviolet rays from
nail is. Constant variables: Initial
sun rays speed of the pail // Same
3. (a) type of pail // Same length
(iii) Refrigerants in the fridge of rope used
or air conditioner // Aerosol
Mass (kg) 40- 45- 50- 55- 60- sprays (iii) Procedure:
44 49 54 59 64
(b) (i) Skin cancer 1. Hang two pails using
Number of 2 5 12 8 3 A drastic climate change
employees (ii) Reduces or stops the use of rope of the same length.

chlorofluorocarbons 2. Empty the left pail, X. Fill
pail Y with sand.

211

  Science Form 4  Answers

3. Push pail X and pail Y same number of protons Solar / Hydro / Wind / Wave /
with the same force. but different number of Biomass / Geothermal
neutrons. C-12 and C−14
4. Start the stopwatch. have 6 protons. C-12 have Non-renewable energy:
6 neutrons but C-14 has 8 Petroleum / Natural gas / Coal /
5. Record time for pail neutrons. C-12 and C-14 Nuclear
X and pail Y to stop are thus isotopes.
(c) The building design is
moving. environment-friendly and built for
energy efficiency.
(iv) Tabulation od data:

Pail Time (s) (iii) Medical: Isotope Cobalt-60 - The building material used is
to kill cancer cells environment-friendly

Agriculture: Isotope

X (no sand) Phosphorus-32 - To detect Efficient generation of energy
the absorption of phosphate like the use of solar panels.
fertiliser
Y (with sand) Efficient water-saving usage
such as the collection and
11. (a) (i) atom / molecule/ ion 12. (a) Energy sector filtration of rainwater.
The usage of solar energy in
(ii) Atom: Iron metal Good management of waste
urban and rural areas // Use of materials.
Molecule: Oxygen gas unleaded petrol // Reduce the
burning of fossil fuels
Ion: Iron ions in rust // Transportation sector
Usage of biofuels or natural
sodium ion in table salt // gas // Usage of hybrid cars //
carbonate ion in limestone / Instalment of electric car charges
Agriculture and Forestry sector
calcium carbonate Planting of mangrove trees at
estuaries or at the beach //
(b) (i) Similarity: both isotope Management of animal faeces
for bio energy // Replanting of
• have the element carbon forests
(any two answers)
• h ave the same number of
protons / 6

(ii) isotopes are atoms of
an element with the

(b) Renewable energy:

212