Focus SPM 2020 F4 KSSM - Biology

SPM

BIOLOGY 4Form

KSSM
2020

Penerbitan Pelangi Sdn Bhd - All Rights Reserved

LDPuraoanggl ruaamgme e

Noor Haniyatie Ibrahim (Textbook Writer) •Jariah Khalib
Sudani Sudin •Rodiah Abd Wahid • Nalini A/P Balachandran

CONTENTS

1Chapter Introduction to Biology and 1 4.4 Lipids 57
Laboratory Rules 4.5 Nucleic Acids 59
SPM Practice 4 61
1.1 Fields and Careers in Biology 2
1.2 Safety and Rules in Biology Laboratory 3 5Chapter Metabolism and Enzymes 63
1.3 Communicating in Biology 4
1.4 Scientific Investigation in Biology 10 5.1 Metabolism 64
11
SPM Practice 1 5.2 Enzymes 64

2Chapter Cell Biology and Organisation 13 5.3 Applications of Enzymes in Daily Life 72

SPM Practice 5 73

2.1 Cell Structure and Function 614 Chapter Cell Division 76
2.2 Living Processes in Unicellular
Organisms 19
2.3 Living Processes in Multicellular 6.1 Cell Division 77
6.2 Cell Cycle and Mitosis 78
Organisms 21
6.3 Meiosis 83
2.4 LOervgealnsiosPmf eOs rngaenirsbatiiotnainnMPueltilcaellnulagri S2d5 n Bhd
-6.A4 llIRssuigeshoftCselRl Deivsiseiornvoen dHuman
27 Health 87
SPM Practice 2 SPM Practice 6 89

3Chapter Movement of Substances 30 7Chapter Cellular Respiration 92
across the Plasma Membrane

3.1 Structure of Plasma Membrane 31 7.1 Energy Production through Cellular
Respiration 93
3.2 Concept of Movement of Substances 32
Across a Plasma Membrane 7.2 Aerobic Respiration 94

3.3 Movement of Substances Across a 7.3 Fermentation 96
Plasma Membrane in Living Organisms 37

3.4 Movement of Substances Across a SPM Practice 7 101
Plasma Membrane and its Application
in Daily Life 45 8Chapter Respiratory Systems in 103
47 Humans and Animals
SPM Practice 3

4Chapter Chemical Composition in a Cell 51 8.1 Types of Respiratory System 104

8.2 Mechanisms of Breathing 110

4.1 Water 52 8.3 Gaseous Exchange in Humans 114
4.2 Carbohydrates 53
4.3 Proteins 56 8.4 Health Issues Related to the Human 116
Respiratory System

SPM Practice 8 118

iii

9Chapter Nutrition and the Human 12.4 Voluntary and Involuntary Actions 188
Digestive System
121 12.5 Health Issues Related to the 190
Nervous System

9.1 Digestive System 122 12.6 Endocrine System 191

9.2 Digestion 123 12.7 Health Issues Related to the Endocrine
System 194
9.3 Absorption 130
SPM Practice 12 196
9.4 Assimilation 131

9.5 Defaecation 133 1 3Chapter Homeostasis and the Human
Urinary System
9.6 Balanced Diet 133 199

9.7 Health Issues Related to Digestive 137 13.1 Homeostasis 200
System and Eating Habits

SPM Practice 9 140 13.2 The Urinary System 205

1 0Chapter Transport in Humans 143 13.3 Health Issues Related to the 209
and Animals Urinary System

SPM Practice 13 211

10.1 Types of Circulatory System 144 1 4Chapter Support and Movement in 214
10.2 Circulatory System of Humans 150 Humans and Animals
10.3 Mechanism of Heartbeat 155

10.4 Mechanism of Blood Clotting 156 14.1 Types of Skeletons 215

10.5 Blood Groups of Humans 158 14.2 Musculoskeletal System of Humans 215

10.6 Health Issues Related to the Human 14.3 Mechanism of Movement and
10.7 LCyirmcuplhaattoircPySSeyystsnetememro fbHiutmaannsP elang11i6630Sdn Bhd14-.4 AHLlolecaRoltmhigoIsthisounte ss RRelaetesdetortvheeHduman 221
Musculoskeletal System 226
10.8 Health Issues Related to the Human
Lymphatic System 165 SPM Practice 14 228

SPM Practice 10 167 Sexual Reproduction,
Development and Growth
1 1Chapter Immunity in Humans 171 1 5Chapter in Humans and Animals 231

11.1 Body Defence 172 15.1 Reproductive System of Humans 232

11.2 Actions of Antibodies 175 15.2 Gametogenesis in Humans 233

11.3 Types of Immunity 176 15.3 Menstrual Cycle 236

11.4 Health Issues Related to Immunity 178 15.4 Development of a Human Foetus 239

SPM Practice 11 178 15.5 Formation of Twins 242

1 2Chapter Coordination and Response 15.6 Health Issues Related to the Human 244
in Humans Reproductive System

181 15.7 Growth in Humans and Animals 245

SPM Practice 15 250

12.1 Coordination and Response 182 PRE-SPM MODEL PAPER 254
12.2 Nervous System 183 269
12.3 Neurones and Synapse 185 ANSWERS

iv

8Chapter Respiratory Systems in Humans
and Animals

Coughing, yawning and sneezing are normal reactions in humans that
involve the expulsion of air from the lungs. What are the differences
between coughing, yawning and sneezing?

Coughing expels impurities and bacteria from
the respiratory track. The thoracic cavity will
contract and the pressure inside the lungs
will increase. The air is pushed out with high
pressure and vibrates the vocal cord, thus
producing coughing sound.

CHAPTERPFeOneCrUbSitan Pelangi Sdn Bhd - All Rights Reserved
8.1 Types of Respiratory
System Sninoohmtaeleetnimooexusyg,ghebntroeafoethxrhinbagolednyco’asrrmnbaoelenlyd.diniTohxreeidrseetfioasnred,
we will yawn to inhale deeper so that
8.2 Mechanisms of more oxygen will enter the body and
Breathing more carbon dioxide can be expelled.

8.3 Gaseous Exchange in
Humans

8.4 Health Issues Related
to the Human
Respiratory System

Sneezing is a way that our body uses
to get rid of rashes due to dust
and bacteria. Air is expelled from the
lungs in force at velocity of 160 km
per hour.

103

  Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

8.1 Types of Respiratory System Insect Respiratory System

1. The respiratory system is influenced by an 1. Insects such as cockroaches and grasshoppers
organism’s anatomy and physiology. conduct respiration via the tracheal system.

2. Different organisms retrieve oxygen from the 2. Gaseous exchange occurs without involving
atmosphere via different respiratory structures. the circulation of oxygen and carbon dioxide.
Instead, the exchange occurs with simple
3. Unicellular organisms do not have specific diffusion between the respiratory surfaces
systems because of their small size. Gaseous and the tissues of the body via air-filled tubes
exchange occur in the form of diffusion. known as the trachea.

3. Structures in the tracheal system include the
spiracle, trachea, tracheoles and air sacs.

Insect Filled with air to speed up the Trachea • Straight tubes which
Cell body transport of respiratory gases to connect to the spiracle
the tissues and brings air into the
body
Air sacs
• Tracheal wall is
Air sac stiffened by chitin
bands to prevent
Chapter the structure from
Chapter collapsing due to air

pressure

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8 Air

Tracheole Spiracles

• Minute branches that break from the trachea • Small holes on both sides of the thorax
• Has thin and moist walls to increase efficiency of and the abdomen of the insect

gaseous exchange • Guarded by valves which allow passage of
• Exist in abundant to increase the total surface air

area for gaseous exchange via simple diffusion • Have hairs that filter out the dust in the air

Figure 8.1 Respiratory structures and their functions in a grasshopper

Fish Respiratory System
1. Gaseous exchange occur in fish via the gills which are tissues with feathery threads called filaments.
2. Bony fish have four pairs of gills protected by operculum.
3. Each gill consists of two rows of filaments supported by gill arches.
4. Each filament contains thin discs called lamellae.
5. Apart from being a site for gaseous exchange, gills also filter particulates like sand so they do not

damage the filaments.

104

Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

Fish Gills Contains many thin discs called lamellae to increase surface
area for gaseous exchange.

Water enter Operculum
Oxygenated blood Closes to protect the gills

Gill arches
Holds thin filaments in place

Filament

Deoxygenated blood

Lamella Thin membraneous discs filled with blood capillaries
to increase the efficiency of gaseous exchange

Figure 8.2 Respiratory structures and their functions in a fish

Amphibian Respiratory System Chapter
Chapter
2. When the frog’s body is fully submerged

1. Amphibians like frogs, salamanders and newts in water, gaseous exchange occurs via the

can live boPtheonnelrabnditaannd Pinewlaatnerg. iTShuds,n Bhd -isnAkvilnol.lvRWesihgbeonhthtitsreisRspoeirnastloearnyrdvo,erggdaasneso, uthseesxkcihnaanngde
the
respiratory structure must be adapted to the lungs. 8

function in both environments.

Amphibians Epidermis • Involves a pair of thin sacs to enable respiratory gases to diffuse
in and out easily.
• The skin is thin and Skin
very permeable to • The wall of the lungs is always moist as they are covered with
respiratory gases. fluids. This allows respiratory gases to diffuse into them.

• The skin is always • Lungs are rich with blood capillary networks to circulate
moist due to the layer respiratory gases to body cells.
of mucus which allow
diffusion of respiratory Lungs
gases.
Kulit
• Below the layer of skin
is a network of blood Mucous
capillaries which carry gland
respiratory gases to
body cells.

Figure 8.3 Respiratory structures and their functions in a frog

105

  Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

Human Respiratory Structure 3. Apart from the respiratory organ, lungs are
also excretory organs that help eliminate
1. Lungs are the human respiratory structures carbon dioxide from the body.
found in the thoracic cavity.

2. Lungs are protected by the rib cage and
intercostal muscles.

Humans Nasal passage

Trachea • A channel for air to flow in and out
Supported by cartilage to ensure the trachea is • Covered in mucus and fine hairs
always open and can receive air
that trap dust

Bronchus

Two branches from the trachea that allow Alveolus
air to flow to the left and right lungs

Bronchioles • The lungs contain millions
of alveoli which provides a

Smaller tubes that branch from the bronchus large surface area for gaseous

and allows air to flow to the alveoli exchange

• Has moist walls that are one cell

Diaphragm thick to allow oxygen to dissolve
and diffuse through

A dome-shaped layer of muscle andChapter • Large network of blood capillaries
Chapter
fibrous tissue that cover the bottom side that provide a large surface area

of the rib cage for gaseous exchange

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Rib cage

8 Surrounds and protects the lungs Ribs

External

intercostal

Intercostal muscles muscle

Wraps the outer and inner sides of the Internal intercostal
rib cage muscle

Figure 8.4 Respiratory structure and functions in humans

EEkxsppeerrimimeennt 82.1

Aim: To study the effect of the increase in total surface area towards diffusion as an analogy in gaseous
exchange

Problem statement: Do small objects have a large total surface area over volume thereby increasing
the substance diffusion rate?

Hypothesis: The smaller the object, the higher the TSA/V and its substance diffusion rate.

Variables:
Manipulated variable: Cube size
Responding variable: Diffusion rate of coloured solution into the cube
Fixed variable: Type of cube and concentration of coloured water

Materials and apparatus: Potato, coloured solution, core borer, sharp knife, tiles, beaker, grid paper,
stopwatch

106

Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

Procedure:
1. Potatoes were cut into four cubes with 4 cm, 3 cm, 2 cm and 1 cm sides respectively.
2. The total surface area and volumes for each cube is calculated.
3. The potato cubes are inserted into beakers containing a coloured solution.
4. The time is measured with a stopwatch.
5. The cubes are left in the solution for 30 minutes.
6. The cubes are removed from the beaker when the time is up.
7. Cube with 4 cm sides are cut in two.
8. The coloured area percentage in each potato is estimated with the help of the grid paper.
9. Steps 7 and 8 are repeated with cubes with 3 cm, 2 cm and 1 cm sides.
10. All data is recorded in a table.
11. Step 9 is repeated using a different piece of grid paper to get the average reading.

Observations:

Length of Total surface Volume (cm3) TSA/V Ratio Estimated coloured
sides (cm) area (cm2) area (%)

16 1 6.0 100

2 24 8 3.0 60

3 54 27 2.0 25 Chapter
Chapter
4 Pene9r6bitan Pelang6i4Sdn Bhd - Al1l.5Rights Reserve1d0
8
Discussion:

1. (a) The cube with the highest TSA/V is the cube with the 1 cm sides.
(b) The cube with the lowest TSA/V is the cube with the 4 cm sides.
(c) The estimated coloured area (%) for the cube with 1 cm sides is 100%.
(d) The estimated coloured area (%) for the cube with 4 cm sides is 10%.

2. (a) The smaller the size, the larger the TSA/V.
(b) The higher the TSA/V the higher the diffusion rate and the larger the coloured area percentage.
(c) Smaller organisms have high TSA/V allowing oxygen to be easily diffused from the atmosphere

into their bodies.

Conclusion:
Hypothesis is accepted. The smaller the object, the higher the TSA/V, and the higher the diffusion rate.

EkAspcteirviimtye8n.12.1

Aim: To study the respiratory structure in insects, fish, amphibian and mammal

A   Cockroach: Tracheae

Procedure:
1. Place a chloroformed dead cockroach on the dissecting board and identify its body parts.
2. Observe and count the number of spiracles on both sides of the cockroach’s thorax and

abdomen.

107

  Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

3. Cut off the feet and wings of the cockroach. Spiracles
Trachea
4. Cut the dorsal area near the spiracles. Be careful to not cut into any
internal organs.

5. Using a magnifying glass, observe the tracheal structure.

6. Draw and label the structures that you can observe.

B   Fish: Gills Figure 8.5 Cockroach respiratory
Procedure: structure

1. Place a fish on the dissecting board.

2. Cut open the operculum from the body of the fish using scissors. Then cut out a piece of the gills.

3. Place the gills in a water-filled petri dish.

4. Identify the gill arches, filaments and lamellae.

5. Take out the gills, remove one gill arch and place it on a piece of white tile.

6. Observe the structure of the gill arch, filament and lamella with a magnifying glass.

7. Draw the gill arch and label the structure.

Operculum

Chapter
Chapter
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8

Gill Mouth Filament Gill arch

Figure 8.6 Steps to remove the fish gill

C   Frog: Lungs

Procedure:
1. Place the chloroformed dead frog on the dissecting board front-up and pin the legs in place.
2. Make an incision in the middle of the body below the ventral.
3. Using the scissors, cut the skin of the frog upwards towards the head and across the sides.
4. Remove the skin layer slowly and pin the skin to the dissecting board.
5. Observe the blood vessels below the layer of the skin.
6. Using the scissors, cut the stomach muscles upwards. Identify the glottis and the lungs.
7. Extract the lungs with the scissors and place them on the white tile.
8. Cut out a cross section of the lungs using a blade.
9. Observe the size, shape and texture of the lungs using a magnifying glass. Sketch and label your

observations.

108

Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

(a) Lift the skin using (b) (c)
forceps

Make incisions Make horizontal
upwards towards incisions

the chin

(d) (e) Lift and cut with (f)

a scalpel

Figure 8.7 Steps to remove the frog’s lungs

D   Rat: Lungs

Procedure:

1. Place the chloroformed dead rat on the dissecting board front-up. Trachea

2. Pin all four limbs in place. Heart
Lungs
3. Make an incision in the middle of the body below the ventral up Diaphragm
towards the jaw of the rat. Chapter
Chapter
4. Continue the incision all the way to the rectum.

5. Pull the skin and pin it on the dissecting board using forceps.

6. tChuotrathceicticsPasuveietynariesourenxbpdiottshaeednt.hPoreaxlavenrtgicialSlydanndBhohrdizo-nAtallllyRsoigthhe ts Reserved 8

7. Cut and move the ribs aside.

8. Identify the trachea, bronchus and lungs using a magnifying glass.

9. Extract the lungs and place it on the white tile. Make a cross section Figure 8.8 Respiratory system
of the lung using a blade. structures in a rat

10. Sketch and label your observations.

Discussion:

1. The respiratory organ for the cockroach is the trachea whereas for the fish, it is the gill. Both the
rat and the frog breathe using the lungs. Frogs can also breathe with their moist skin.

2. The respiratory structures for each specimen is as follows:

Specimen Respiratory structures
Cockroach Spiracle, trachea, air sac
Gill arch, filament, lamellae
Fish Lungs, glottis, moist skin
Frog Trachea, bronchus, lungs
Rat

3. The respiratory surface for the cockroach is the tracheal, for the fish is the lamellae, for the frog is
the lung and moist skin, and for the rat is the alveoli.

4. The respiratory organs in the cockroach, fish, frog, and rat have large surface areas to increase
diffusion rate.

109

  Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

Comparison of human and animal respiratory structures

Table 8.1 Comparison of human and animal respiratory structures

Similarities

• Have specific organs for respiration
• Respiratory surface is always moist, has a high TSA/V ratio and full of blood capillary networks.
• Gaseous exchange occurs via diffusion

Differences

Aspect Humans Insects Fish Amphibians

Respiratory organ Lungs Tracheae Gills Skin and lungs
Respiratory surface Bronchioles Lamellae Skin and lungs
Alveoli
Respiratory structure Spiracle, tracheae, Mouth, mouth cavity, Nostril, mouth, glottis,
Nostrils, nasal cavity, tracheole gills lungs
trachea, bronchus,
bronchiole, alveoli

Checkpoint 8.1 3. When the volume of the cavity increases,
the internal air pressure becomes lower than
1. Frogs have two respiratory organs. Name and the atmospheric pressure and air is forced
describe the adaptations found in both organs inwards.
which increase the gaseous exchange efficiency.

2. Humans have two lungs that contain millions of 4. When the volume of the cavity decreases,
Chapter
Chapter alveoli covered with blood capillaries. State its the internal air pressure becomes higher than

significance. Penerbitan Pelangi Sdn Bhdtohu-etwAaaltrmldsoR.sipghehritcspRreesssuree ravneddair is forced

8 8.2 Mechanisms of Breathing Grasshopper Breathing Mechanism

Air sacs

1. The act of breathing in and out is aided by
the difference in pressure inside the breathing
cavities of organisms.

2. The change in pressure is produced by Trachea Spiracles
manipulating the volume of the cavity.

Figure 8.9 Grasshopper breathing structure

When breathing in: Abdominal pressure increases Air enters the tracheae and
and the air pressure in the tracheoles via the spiracles
The grasshopper’s abdominal
muscles relaxes and the tracheae is reduced
spiracle valve opens

When breathing out: Abdominal pressure decreases Air exits via the spiracles
and the air pressure in the
The grasshopper’s abdominal
muscles contracts tracheae is raised

Figure 8.10 Grasshopper breathing mechanism

110

Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

Fish Breathing Mechanism

When breathing in: Mouth opens When breathing out: Mouth closes

Mouth opens and the Mouth closes and the
base of the mouth is base of the mouth is

lowered raised

The operculum closes Gill The operculum opens Gill

The space in the mouth Operculum Operculum
increases, lowering the close open
pressure in the mouth
The higher pressure The space in the mouth The operculum opens
outside pushes water decreases, raising the and water flows out
into the mouth, carrying pressure in the mouth through the gills
dissolved oxygen into

the mouth cavity

Figure 8.11 Fish breathing mechanism

Frog Breathing Mechanism When breathing out:

When on land, frogs breathe through the nostrils.
When breathing in:

12 34 Chapter
Chapter
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The nostrils open, the The nostril closes, The lung muscles The deoxygenated air 8
base of the mouth cavity the base of the mouth contract and the mixes with the air in the
raises and the glottis pressure inside the
lowers and the glottis mouth cavity
opens abdomen rises
closes

The volume inside the As the volume inside The glottis opens and The nostrils open
mouth cavity increases, the mouth cavity the deoxygenated air and the glottis opens,
lowering the pressure eliminating the air inside
decreases, the internal exits the lungs
pressure increases. The

glottis opens and air

rushes into the lungs

Figure 8.12 Frog breathing mechanism

Human Breathing Mechanism

Table 8.2 Human breathing mechanism

When breathing in When breathing out

Contracts Outer intercostal muscles Relaxes

Relaxes Inner intercostal muscles Contracts
Moves upwards and outwards Rib cage Moves downwards and inwards

Contracts and flattens downwards Diaphragm Relaxes and arches upwards

Increases Thoracic cavity volume Reduces
Pressure reduces and air is forced in Pressure and air movement Pressure increases and air is forced out

111

  Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

Breathing in Breathing out

Air flows in Air flows out

Rib cage moves Ribs Rib cage moves Ribs
upwards and Diaphragm inwards and Diaphragm
outwards when downwards
the external when the inner
intercostal intercostal
muscles contract muscles contract

Diaphragm contracts and Diaphragm relaxes, arches
flattens downwards upwards in a dome shape

Figure 8.13 Human breathing mechanism

EkAspcteirviimtye8n.2.1

Aim: Building a lung model to show the movement of the diaphragm during breathing

Materials and apparatus: Thin rubber sheet, perforated rubber cork, rope, grease, balloons, bell jar,
y-shaped tube and glass tube

Procedure:

Glass tube

Chapter Bell jar
Chapter
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8 expands contracts

(a) Thin rubber (b)
sheet

Figure 8.14 Human respiratory system model

1. Build a human respiratory system model as shown in Figure 8.14.
2. Secure a balloon on each of the ends of the Y-shaped tube.
3. Insert the rubber cork into the Y-shaped tube inside the bell jar from below.
4. Apply some grease on the cork so it is airtight.
5. Secure the thin rubber sheet at the base of the bell jar.
6. Tie a piece of rope to the rubber sheet.
7. Pull the rope downwards. Observe the effect on the balloon (Figure 8.14 (a)).
8. Push the rubber sheet upwards and into the bell jar. Observe the effect on the balloon (Figure 8.14 (b)).
9. Complete the table below.

Observations:

Procedure Observations

Rubber sheet pulled downwards Balloons expand

Rubber sheet pushed upwards and into the bell jar Balloons relax

112

Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

Discussion:
1. The bell jar model represents the structure in the actual respiratory system in humans as follows:

Model Human respiratory system
Bell jar Thoracic cavity
Balloon Lungs
Rubber sheet Diaphragm
Y-tube
Trachea and bronchus

2. Here is how the model represents the breathing mechanism.

Breathing in mechanism Breathing out mechanism

Model Respiratory system Model Respiratory system

Rubber sheet is Diaphragm contracts Rubber sheet is Diaphragm relaxes
pulled down pushed up

Volume in the bell Volume in thoracic Volume in the bell Volume in thoracic
jar increases cavity increases
jar reduces cavity reduces

Pressure inside the Pressure inside Pressure inside the Pressure inside
bell jar reduces the thoracic cavity bell jar increases the thoracic cavity

reduces increases
Chapter
Chapter
Air is forcPedeinnteo rthbeitaAnirPisefolracendginitSo dthne BhdA-irAisllfoRrciegdhouttsinRtoesAeirrivsefodrced out into
balloon lungs the atmosphere the atmosphere
8
Conclusion:

When breathing in, the diaphragm contracts and flattens, the volume in thoracic cavity increases,
the pressure reduces and air is forced into the lungs. When breathing out, the diaphragm relaxes and
arches upwards, the volume in thoracic cavity decreases, the pressure increases and air is forced out
of the lungs.

EkAspcteirviimtye8n.32.1

Aim: T o design a model that shows the antagonistic action of intercostal muscles during breathing

Materials: T hin board strip, ice cream sticks, rubber bands, nails

Procedure: Rubber Ice cream
band A stick A
1. Build the rib cage model as shown in Figure 8.15.
Ice cream Nail
2. When each rubber band is stretched, observe and record stick B
the movement of the board strip and ice cream sticks.

Ice cream Board
stick C strip

Rubber
band B

Figure 8.15 Rib cage model

113

  Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

Observation: Observation
Procedure Ice cream stick B is lowered
Ice cream stick B is raised
Rubber band A stretched
Rubber band B stretched

Discussion:
1. The rib cage model represents the structure in the respiratory system in humans as follows:

Model Human respiratory system
Rubber band A Inner intercostal muscles
Rubber band B Outer intercostal muscles
Ice cream stick B
Ice cream stick A Sternum
Ice cream stick C Rib cage
Rib cage
Board strips
Spine

2. (a) When the outer intercostal muscles contract, inner intercostal muscles relaxes, the rib cage is

Chapterpulled upwards and outwards.
Chapter
(b) This raises the volume in the thoracic cavity.

(c) AThireisprfoesrcsuPerdeeininnteothrtehbethiltouarnagnc.icPceavlaitynbgecioSmdesnloBwherdth-anAlthleRaitmgohstpsheRricepsreesrsuvree.d
(d)

8 3. (a) When the inner intercostal muscles contract, outer intercostal muscles relaxes, the rib cage is
pulled downwards and inwards.

(b) This lowers the volume in the thoracic cavity.
(c) The pressure in the thoracic cavity becomes higher than the atmospheric pressure.

(d) Air is forced out of the lung.

Conclusion:

The movement of inner and outer intercostal muscles causes the air to move out of and into the lungs
during the breathing process.

Checkpoint 8.2 8.3 Gaseous Exchange in Humans

1. How does fish: 1. Gaseous exchange between the lung and
(a) increase the volume in the mouth cavity? blood occur via simple diffusion.
(b) decrease the volume in the mouth cavity?
2. Apart from that, this exchange is aided by the
2. The two opercula on an injured fish are torn. In difference in the partial pressure for oxygen
your opinion, does this injury affect the breathing and carbon dioxide.
process? Explain.

114

Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

Table 8.3 The difference between the concentration, partial pressure of oxygen and carbon dioxide at the alveoli
and blood capillary

Alveolus Blood capillaries
High oxygen concentration Low oxygen concentration
Low carbon dioxide concentration High carbon dioxide concentration
High partial pressure for oxygen Low partial pressure for oxygen
Low partial pressure for carbon dioxide High partial pressure for carbon dioxide

Exhaled air Inhaled air

Alveolus wall
(one-cell thick)

Blood in the blood capillary Alveolus Blood in the blood capillary
leading towards the alveolus leading away from the
have a high partial pressure Carbon alveolus have a high partial
for carbon dioxide and low dioxide pressure for oxygen and
partial pressure for oxygen.
Oxygen low partial pressure for

carbon dioxide.
Chapter
Red blood Chapter
cell

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Figure 8.16 Gaseous exchange across the surface of the alveolus and blood capillaries in the lungs 8

• Gas diffusion occurs from an area of high partial pressure to an area of low partial pressure.

1 • Inhaled air is rich with oxygen causing the partial pressure for oxygen in the alveolus to be higher than the partial

pressure in the blood capillary.

• Thus, oxygen dissolves into the moist alveoli walls and diffuse out from the alveolus into the blood capillary.

2 • Oxygen combines with the haemoglobin in the blood capillaries to form oxyhaemoglobin.
• Oxygen is carried from the lungs to the whole body in the form of oxyhaemoglobin.

Haemoglobin + Oxygen In the lungs Oxyhaemoglobin

In the body
cells

• When it arrives at the body cells, oxyhaemoglobin will break down and release the oxygen it carries due to the

3 lower partial pressure of oxygen.

• The released oxygen will diffuse through the wall of the blood capillaries into the cells. Oxygen is used in cell
respiration.

115

  Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

• Cell respiration releases carbon dioxide leading to a higher partial pressure for carbon dioxide inside the cell

4 compared to inside the blood capillary.

• Carbon dioxide diffuses from the body cell to the blood capillary.

5 • Carbon dioxide from the body cell is carried through three ways:
 7% is dissolved in the blood plasma.

 23% combines with the haemoglobin in the red blood cells (erythrocytes) and carried in the form of
carbaminohaemoglobin.

 70% is in the form of bicarbonate ions, HCO – in the blood plasma
3

– Carbon dioxide diffuses into the erythrocytes and combine with water to form carbonic acid (H2CO3). This
reaction is catalysed by carbonic anhydrase.

– Carbonic acid, H2CO3 is broken down to bicarbonate ions, HCO3– and hydrogen ions, (H+). Bicarbonate
ions, HCO – diffuse into the blood plasma and is carried to the lungs.
3

– Bicarbonate ions, HCO3– diffuse again into the erythrocytes and combines with hydrogen ions, H+ to form
carbonic acid (H2CO3) once again.

– Carbonic acid (H2CO3) break down to carbon dioxide and water.

– The partial pressure for carbon dioxide in the blood capillary is higher than the partial pressure for

carbon dioxide in the alveolus.

– Therefore, carbon dioxide in blood plasma and erythrocytes diffuse through blood capillaries and alveolus
wall into the alveolus.

– Carbon dioxide is exhaled into the atmosphere via the mouth and nose.

Chapter
Chapter
CheckpoiPnet nerbitan Pelangi Sdn Bhd - All Rights Reserved 8.3

8 1. Oxygenated and deoxygenated blood is obtained from a specimen. How do you identify which blood is which?
2. Oxygen from the lungs is carried to the body cells in the form of oxyhaemoglobin that is the combination between
oxygen and haemoglobin. Meanwhile, carbon dioxide from the body cells are carried to the lungs to be eliminated
via three ways that are carbaminohaemoglobin, dissolved in blood plasma and in the form of bicarbonate ions.
What is the need to eliminate this gas from the body?

8.4 Health Issues Related to the Human Respiratory System

1. Chronic Obstructive Pulmonary Disease (COPD) is a disease caused by an obstruction in the respiratory
pathways due to swelling or long-term coughing leading to inflammation of the respiratory pathways
and obstruction of airflow to the lungs.

2. The primary cause of COPD is smoking or long term exposure to polluted air.

3. COPD is not gender-specific and the risks for COPD increases with age.

4. The most common symptom is shortness of breath during physical activities and in the mornings, long-
term caughing as well as wheezing. COPD patients often experience lung failure and inflammation of
the heart.

5. Example of COPD include asthma, acute bronchitis and emphysema.

116

Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

Emphysema

Emphysema involves damage to the
alveoli which has become less elastic and
cannot expand much during breathing.
This leads to shortness of breath. If left
untreated, the alveoli will expand and
burst. This will reduce the gas exchange
surfaces.

Chronic bronchitis

Trachea Narrowed Chronic bronchitis is a disease
airway caused by the infection or
inflammation of the bronchus

pathways which causes the
Chapter
pathways leading to theChapter

lungs to become narrow.
Chronic bronchitis patients will
experience long term coughs
Penerbitan Pelangi Sdn Bhd - All Rights ReservedThickening
walls
with a lot of sputum.
Normal 8

respiratory Respiratory airway

Lungs airway of asthmatic patient

Asthma Normal bronchus airway Inflamed bronchus airway

Asthma involves chronic inflammation of the respiratory
pathways. The airways redden, swell and produce
excessive mucus. This leads to the narrowing of the
airways. Asthmatic patients may experience wheezing
as well as shortness of breath on top of difficulties when
doing physical activities.

Checkpoint 8.4

1. (a) What does COPD mean?
(b) What diseases are associated with COPD?
(c) Name the symptoms for COPD?

2. Abu, a Form 3 student in SMK Purnama often have difficulties breathing after Physical Education class. His
teacher brought him to the clinic. The doctor asked if he has problems breathing when he wakes up and often
have coughs with phlegm. In your opinion, does the doctor suspect that Abu has COPD? Explain.

117

  Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

cCONCEPT MAP RESPIRATORY SYSTEMS IN
HUMANS AND ANIMALS

Insect Tracheae system Comparison based on
Fish Gill and Breathing
Amphibian Lungs Mechanism Oxygen
Carbon dioxide
Skin Asthma
Humans Lungs Chronic bronchitis
Emphysema

Chapter SPM Practice 8
Chapter
Penerbitan Pelangi Sdn Bhd - All Rights Reserved
8 Objective Questions 3. Which of the following is the What is R?
SPM site for gaseous exchange A Trachea

1. Which of the following 2016 for human and insect? B Alveolus

SPM happen to reduce the C Bronchus

2015 amount of carbon dioxide in Human Insect D Bronchiole

blood after one exercises? A Alveolus Tracheole

Heart Breathing 5. Figure 2 shows a respiratory
rate rate
B Alveolus Trachea SPM system of an insect.

2016

A Reduced Reduced C Lungs Tracheole J

B Reduced Increased D Lungs Trachea

C Increased Reduced 4. Figure 1 shows a respiratory
D Increased Increased
SPM structure.

2016

2. Which of the following are R Figure 2
SPM adaptations of the frog’s skin Figure 1
2016 for gaseous exchange? What process occurs in J
during gaseous exchange in
A Moist and rich with blood insects?
capillaries A Osmosis
B Simple diffusion
B Smooth and dry C Facilitated diffusion
C Thick and moist D Active transport

D Folded and thin

118

Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

6. Figure 3 shows the gaseous 8. Figure 4 shows the human 9. Figure 5 shows a tracheae
SPM exchange between body
2017 cells and blood capillaries. SPM breathing mechanism. SPM system in an insect.

Y 2017 2017

Z

ZX

Figure 5

RR SS What is Z?

Figure 3 Figure 4 A Tracheae
Which of the statements is B Spiracle
What is the partial pressure C Muscle
of carbon dioxide at X, Y true about Figure 4? D Tracheole
and Z?
RS 10. A group of students climbed

XYZ A Flattened Dome- SPM to the peak of Mount
A Low High Low diaphragm shaped 2018 Kinabalu. The following are

diaphragm changes that the students

experience.

B High High Low Outer Outer

C Low Low High B intercostal intercostal P – Breathing rate
muscle muscle increases

D High Low High contracts relaxes Q – Oxygen decreases in
the blood
The
volume in The volume R – The partial pressure Chapter
the lungs in the lungs of oxygen intoChapter

decrease increase alveolus decreases
7. What structure in the C
SPM respiratory system of the fish Which of the following shows
2017 increases the surface area The air the correct order of the 8
pressure changes that occur?
Penerbitan Pelangi Sdn Bhd - All Rights Reservedfor gaseous exchange? A P, Q and R
in the B R, P and Q
A Filament alveolus is C Q, R and P
B Gill arch
C Operculum low
D Base of the mouth
D The air
pressure in

the alveolus
is high

D Q, P and R

Subjective Questions
Section A

1. Figure 1 shows part of the human respiratory system.

R
P
Q


Figure 1

119

  Biology Form 4  Chapter 8  Respiratory Systems in Humans and Animals

(a) (i) Name structures P and Q. [2 marks]
(ii) Explain the characteristics for P that is associated with its functions. [3 marks]

(b) (i) A heavy smoker will cough for long periods of time. Explain how this habit reduces the efficiency of

his respiratory system. [3 marks]

(ii) Explain one disease that the smoker might have. [2 marks]

(c) Suggest a way to increase the ventilation rate when breathing. Explain. [2 marks]

Section B
2. (a) Figure 2.1 shows the human respiratory structure.


Figure 2.1

Chapter Explain the specific adaptations for the respiratory structure. [6 marks]
Chapter
(b) Give a reasonable reason to stay away from smoking. [10 marks]
Penerbitan Pelangi Sdn Bhd - All Rights Reserved
(c) A student conducted an experiment to study the breathing rate of an athlete. Figure 2.2 shows a graph
8 depicting the changes in the air volume inside the lungs of an athlete during a period of rest and during
a period of intensive exercise.

2.0

Volume of air (dm3) 1.5
1.0

0.5

Time (second)
0 10 20 30 40 50 60

Resting Intensive training
phase phase

Figure 2.2

Why is the volume of air in the lungs higher during the period of intensive exercise compared to the

period of rest? [4 marks]

120

1Chapter Introduction to Biology and SPM Practice 1 enhance detergents so that clothes
Laboratory Rules get cleaner. In food technology,
Objective Question food can be modified to make it
Checkpoint 1.1 taste better and more nutritious.
1. D 2. D 3. A 4. D 5. D Preservation methods can prolong
S1 3 research fields in biology: 6. A 7. A 8. B 9. C 10. D expiry date of food. Stem cells
• Zoology – The study of animals have the potential to cure chronic
Subjective Questions diseases such as spinal cord injury
which includes structure, physiology, and heart disease.
development and classification. Section A (c) Examples of personal protective
• Cytology – The study of cells which equipment that can be worn during
includes structure, cell composition 1. (a) How does physical activity affect surgery are mask, safety goggles,
and interaction with other cells. pulse rate? gloves and laboratory coat. The
• Anatomy – The study of bodily equipment is worn to prevent from
structure of humans, animals and (b) As the physical activity increases, contacting with spurted blood or
other organisms. pulse rate also increases. other body fluid.
S2 • Five examples of biotechnological (d) Determine the problem statement,
products that are available at home: (c) (i) Manipulated variable: Types of make hypothesis, plan investigation,
Clothes detergent, yogurt, cosmetics, activity determine and control variables,
plastics and fabrics perform experiment, collect data,
Method to handle: Use different analyse data, interpret data, make
Checkpoint 1.2 types of activities conclusion and write report.

(ii) Responding variable: Pulse rate
count

Method to handle: Count and
record the pulse rate in a minute

(d)

150

S1 Three protective equipments and their

functions: 100 2Chapter Cell Biology and
• Laboratory coat – Protects clothing Organisation

from spilt chemical.
• Gloves – Protects hands from heat

and chemical reactions. Checkpoint 2.1
• Face mask – Filters fine particles

bigger than 5 micrometres such as
bacteria, spores, fungi, solid particles

Penerbitan Pelangi Sdn Bhd - All Rights Reservedand liquid particles from entering
50 S1 Nucleus, cytoplasm and plasma membrane.
S2 Presence of water in vacuole produces

turgor pressure in herbal plants. Turgor

respiratory system. pressure is important for herb to maintain

S2 Materials that can be discarded into 0 Zulfati Sarah its shape and prevent it from wilting.
laboratory sink: 100 ml distilled water, Husna
0.1 M sodium hydroxide Checkpoint 2.2
Resting Walking Jogging
Materials that cannot be discarded into 1. (a) K: Food vacuole
laboratory sink: Concentrated sulphuric (e) As the physical activity increase, L: Nucleus
acid, matchstick pulse rate also increases. This M: Pseudopodium
shows that more oxygen in the N: Plasma membrane
Checkpoint 1.3 blood is pumped from the heart (b) Structure M is involved in the
to the rest of the body to produce
S1 Vertical axis: Responding variable more energy. movement and capture of food.
Horizontal axis: Manipulated variable Structure M is projected towards
S2 Dorsal view of a fish (f) Heartbeat its target. Cytoplasm flows into the

Section B projected structure M to change
its position. Structure M captures
S3 Histogram. It shows frequency 2. (a) (i) Ecology is a scientific food and subsequently forms food
distribution of data in ranges value. Its study on distribution of vacuole.
x-axis shows range of marks whereas organism, interactions among (c) Nucleus of a matured Amoeba
y-axis shows frequency of pupils. organisms, and interactions sp. divides by shrinking along the
between organisms and their middle. Cytoplasm divides into
Checkpoint 1.4 environment. two parts after the nucleus has
completely divided. Finally, two new
S1 Three things that are needed in (ii) Nanotechnology is a branch cells are formed.
the procedure when planning an of technology that focuses
experiment: Data collection, selection of on manipulation of materials Checkpoint 2.3
apparatus and materials, and planning smaller than 100 nanometres.
of procedure to be carried out. S1 Smooth muscle cell, cardiac muscle cell
(iii) Longitudinal section is a section and skeletal muscle cell.
S2 A report shows the flow of research done along the long axis of a
methodology in the experiment. It also structure of organism, organ or S2 Meristem cells at the tips of shoot and
shows how the observations were tissue. root require much energy to perform
recorded; the data was analysed and active cell division for growth.
evaluated. In addition, future research to (b) Genetic engineering is used
be carried out was suggested; and the in livestock and agriculture to Checkpoint 2.4
conclusion was presented to summarise produce better quality organisms.
the research outcome based on the For example, tomato which does S1 Cell → Tissue → Organ → System →
results. not turn squishy, and remain Organism
fresh longer. In medicine, vaccine
is produced to prevent against S2 Nose and lungs
diseases. Enzymes are produced to S3 Endocrine hormones

269

  Biology Form 4  Answers

S4 Pancreas. Digestive system and as carbohydrate, protein, Checkpoint 3.2
endocrine system. phospholipid and glycoprotein.
For examples, K modifies S1 Osmosis is a process by which
SPM Practice 2 5. C protein to enzyme. L is rough water molecules pass through a
endoplasmic reticulum. L semipermeable membrane from a less
Objective Questions 4. C functions in transporting protein concentrated solute solution (higher
1. C 2. B 3. A synthesised by ribosome to concentration of water molecules) into a
cell surface and packages more concentrated solute solution (lower
Subjective Questions the protein into vessicle to be concentration of water molecules).
transported to other parts of
Section A cell. M is the nucleus. Nucleus S2 (a) Nucleic acid – facilitated diffusion
consists of chromosomes which (b) Sodium ion – active transport
1. (a) (i) Cell consists of cell wall, carry genetic information. This (c) Glycerol – simple diffusion
chloroplast and large vacuole information will determine the S3 (a) In passive transport, movement of
characteristics of offspring.
(ii) P: Cell wall Nucleus also controls all molecules does not require energy
Q: Chloroplast activities of a cell. whereas active transport requires
R: Mitochondria (ii) 1. Palisade mesophyll cell energy.
(iii) P is made up of tough cellulose (b) Movement of molecules by passive
contains lots of chloroplasts transport is in the direction (along)
fibres. It provides support to cell and are closely arranged to of its concentration gradient
and maintain its shape. ensure maximum absorption whereas in active transport,
(b) (i) Amoeba sp. is a single-celled of light energy. molecules move against its
microorganism which performs 2. R oot hair cell has a large concentration gradient.
all functions of a complete living surface area to allow maximum S4 Movement of potassium ion by active
organism. absorption of water. transport:
(ii) Water diffuses into a vacuole of (b) Nutrition • Potassium ion requires ATP energy
a flaccid Amoeba sp. Its vacuole Movement of cilia directs food and protein carrier to move against
enlarges and pushes against into oral groove. Food is digested concentration gradient in order to
the plasma membrane until it by enzymes secreted into food cross plasma membrane.
reaches its maximum size. The vacuole. Nutrient is absorbed into • Potassium ion attaches to active site
vacuole contracts and excretes cytoplasm whereas waste product is of protein carrier.
excess water. Amoeba sp. does excreted out through its anal pore. • ATP dissociates to release phosphate
not burst. molecule which binds to carrier
(iii) Lysosome fuses with food protein (of plasma membrane) and
vacuole. Lysosome releases
lysozyme to digest bacteria.

Digested food is absorbed Osmoregulation alters the shape of the carrier protein

by Amoeba sp. whereas Paramecium sp. contains contractile to allow potassium ion to cross

undigested food is excreted. vacuole which controls entry of plasma membrane.

2. (a) excess water into it. Whenever • Carrier protein regains its original
Penerbitan Pelangi Sdn Bhd - All Rights ReservedStructure
Level of cell contractile vacuole is filled shape.
organisation with water, it moves to plasma
Checkpoint 3.3
membrane and excretes excess

water. Osmoregulation prevents S1 (a) Blood

(a) Cell Paramecium sp. from bursting. (b) Concentrated salt solution is
hypertonic to red blood cells. Water
(b) Cell Asexual reproduction diffuses out of red blood cell by
structure Paramecium sp. performs asexual osmosis. The red blood cells shrink
and experience crenation.
(c) Organ reproduction by binary fission.
Each Paramecium sp. divides (c) Animal cell does not contain cell
once to produce two similar cells, wall. Absence of cell wall does not
which develop into two individual allow red blood cell to maintain its
Paramecium sp. shape. Shape of red blood cell that

3Chapter experiences crenation:

(d) System Movement of Substances
across a Plasma Membrane

(b) (i) Reproductive system of man. Checkpoint 3.1 S2 Transport of mineral ions into grass
Function: Produce sperms to roots of grass is by active transport.
fertilise ovum. S1 Channel proteins and carrier proteins When cell respiration stops, no energy
S2 • Main components of plasma is produced to carry out active transport,
(ii) Sperm has tail to facilitate therefore transport of mineral ions into
swimming towards ovum. membrane are proteins and root stops.
phospholipids whereas the main
(c) Cell cannot swim towards ovum components of cell wall are celluloses. Checkpoint 3.4
because it does not have energy. • Plasma membrane is semi-permeable
Fertilisation does not occur. whereas cell wall is fully permeable. S1 (a) Food preservation method
S3 Plasma membrane consists of bilayer (b) Advantages:
(d) Multicellular organism consists of phospholipid with different types of • Add flavour
many cells. It requires specialised proteins partially or fully embedded • Last longer
cells to perform specific functions. in the membrane. The description • Looks better
Multicellular organism requires above is known as the fluid mosaic
specific systems to fulfill the model of plasma membrane. Plasma Disadvantages:
requirements of its body. membrane components are always • Less nutritious
in free motion and their positions are • High in sugar/salt content
Section B constantly changing. This explains why
plasma membrane possesses fluidic
3. (a) (i) K is Golgi apparatus. K characteristic.
functions as a centre for
processing, packaging and
transporting substances such

270

FOCUS SPM 4Form CC034440 FOCUS SPM

KSSM
2020

BIOLOGY

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