GASEOUS EXCHANGE

Introduction. Gaseous exchange in plants.

By the end of the lesson, the learner should be able to:


To explain importance of gaseous exchange.

To describe gaseous exchange in plants.

Discussion
Explanations

Q/A: Products of respiration.
Detailed discussion.

text book

K.L.B. BOOK 2
P. 48

GASEOUS EXCHANGE

Release of CO2 by plants.

By the end of the lesson, the learner should be able to:
To describe an experiment to show release of CO2 by plants.

Class experiments including control experiments.

Explain the observations made.

Bicarbonate indicator, boiling tubes, Aluminum foil.

K.L.B. BOOK 2
P. 49

GASEOUS EXCHANGE

Release of O2 by plants.

By the end of the lesson, the learner should be able to:
To describe an experiment to show release of O2 by plants.

Teacher demonstration: Test for the gas evolved.
Discuss observations.

Gas jar,
Glass funnel,
Water plant,
Beaker.

K.L.B. BOOK 2
P. 49

GASEOUS EXCHANGE

Stomata.

By the end of the lesson, the learner should be able to:
To describe the structure and explain the functions of stomata.

Detailed discussion.
Drawing diagrams.

text book

K.L.B. BOOK 2
P. 51

GASEOUS EXCHANGE

Opening & closing of stomata.
Stomata and habitats of plants.

By the end of the lesson, the learner should be able to:
To describe and explain the mechanism of opening & closing of stomata.


To relate plant habitats and the no. of stomata.
To explain the variation between number of stomata on the upper and lower face.

Detailed discussion.
Observe number of stomata of prepared slides of hydrophytes and xerophytes.

Discuss the observations.

text book
Prepared slides of hydrophytes and xerophytes.

K.L.B. BOOK 2
P. 51

GASEOUS EXCHANGE

Lenticels.
Respiratory surfaces in animals.

By the end of the lesson, the learner should be able to:
To describe and explain the mechanism of lenticels.
To define a respiratory surface.
To state characteristics of respiratory surfaces.
To identify the environment or medium of operation of respiratory surfaces.

Detailed discussion.
Teacher exposes meaning of a respiratory surface.
Discuss at length, giving examples of organisms that have a given respiratory surface.

text book

K.L.B. BOOK 2
P. 52

GASEOUS EXCHANGE

Gaseous exchange in protozoa.

By the end of the lesson, the learner should be able to:
To describe the mechanism of gaseous exchange in an amoeba.

Q/A: Review diffusion, structure of an amoeba.
Discuss briefly gaseous exchange in and out of amoeba.

text book

K.L.B. BOOK 2
P. 53

GASEOUS EXCHANGE

Gaseous exchange in insects.

By the end of the lesson, the learner should be able to:
To describe the mechanism of gaseous exchange in insects

Drawing tracheal system of a grasshopper.
Discuss at length the structure of the tracheal system.
Detailed discussion.

text book

K.L.B. BOOK 2
PP. 53, 54

GASEOUS EXCHANGE

Breathing in insects.

By the end of the lesson, the learner should be able to:
To describe the breathing mechanism in an insect.

Observe breathing movements of live specimens of grasshoppers, locusts or cockroaches.

Live specimens of insects,
Hand lenses,
Boiling tubes.

K.L.B. BOOK 2
P. 56

GASEOUS EXCHANGE

Breathing in insects.

By the end of the lesson, the learner should be able to:
To describe the breathing mechanism in an insect.

Observe breathing movements of live specimens of grasshoppers, locusts or cockroaches.

Live specimens of insects,
Hand lenses,
Boiling tubes.

K.L.B. BOOK 2
P. 56

GASEOUS EXCHANGE

Number, position and shape of spiracles of insects.
Gaseous exchange in a bony fish.

By the end of the lesson, the learner should be able to:
To give an account of the number, position and shape of spiracles of insects.
To describe the structure of gills of a bony fish.
To explain how a gill is adapted to function as a respiratory surface.
To explain the mechanism of gaseous exchange in gills.

Drawing the abdomen and showing the position and shape of spiracles, and giving reasons thereof.
Drawing and labeling a gill of a fish; stating the function of each part; and stating how it is adapted to its functions.
Detailed discussion.

Live specimens of insects.

A gill of a fish.

K.L.B. BOOK 2
P. 56

GASEOUS EXCHANGE

Gaseous exchange in amphibians.

By the end of the lesson, the learner should be able to:
To explain the mechanism of gaseous exchange in a frog.

Q/A: Various methods of gaseous exchange in a frog.
Discuss gaseous exchange through the mouth, lungs and skin of a frog.

text book

K.L.B. BOOK 2
P. 58

GASEOUS EXCHANGE

Gaseous exchange in mammals.
The structure of the lungs.

By the end of the lesson, the learner should be able to:
To list down parts of the tracheal system in man.
To describe the function of the parts of a system respiratory.


To explain adaptations of the lungs to their functions.

Discuss at length man?s respiratory system.
Drawing labeled diagrams coupled with explanations.

Wall chart- Respiratory system in man.
Wall charts- Structure of lungs.

K.L.B. BOOK 2
P. 59
K.L.B. BOOK 2
P. 60-1

GASEOUS EXCHANGE

Inhalation.

By the end of the lesson, the learner should be able to:
To describe the process of inhalation in man.

Showing movements of ribs during inhalation.
Explain the inhalation mechanism.

Chart / model of a rib cage.

K.L.B. BOOK 2
PP. 61-62

GASEOUS EXCHANGE

Exhalation.

By the end of the lesson, the learner should be able to:
To describe the process of exhalation in man.

Showing movements of ribs during exhalation.
Explain the exhalation mechanism.

Chart / model of a rib cage.

K.L.B. BOOK 2
PP. 61-62

GASEOUS EXCHANGE

Thoracic cavity model.

By the end of the lesson, the learner should be able to:
To identify similarities between a model thoracic cavity and an actual thoracic cavity.

Teacher presents a model thoracic cavity.
Q/A: Comparing parts of the model cavity and the actual rib cage.

Thoracic cavity model.

K.L.B. BOOK 2
PP. 61-63

GASEOUS EXCHANGE

Gaseous exchange in an alveolus.
Rate of breathing in man.

By the end of the lesson, the learner should be able to:
To describe gaseous exchange in an alveolus.
To explain regulation of breathing in man.


To state and explain briefly factors affecting the rate of inhalation / exhalation processes.

Discussion and explanations.

text book

K.L.B. BOOK 2
P. 64
K.L.B. BOOK 2
P. 63

GASEOUS EXCHANGE

Intercostal muscles.

By the end of the lesson, the learner should be able to:
To explain the function of intercostal muscles during the breathing system.

Detailed discussion.
Counting number of inhalations before and after an exercise blow.

Lime water, rib cage model.

K.L.B. BOOK 2
P. 66

GASEOUS EXCHANGE

Intercostal muscles.

By the end of the lesson, the learner should be able to:
To explain the function of intercostal muscles during the breathing system.

Detailed discussion.
Counting number of inhalations before and after an exercise blow.

Lime water, rib cage model.

K.L.B. BOOK 2
P. 66

GASEOUS EXCHANGE

Inhaled and exhaled air.

By the end of the lesson, the learner should be able to:
To test for CO2 in the air we inhale/ exhale.

Observe colour changes of lime water, and make deductions.
Brief discussion.

Lime water.

K.L.B. BOOK 2
P. 67

GASEOUS EXCHANGE

Diseases of the respiratory system.

By the end of the lesson, the learner should be able to:
To state the causes, symptoms and prevention of respiratory diseases.

Discuss cause, symptoms and prevention of whooping cough TB, bronchitis, etc.

Resource person.

K.L.B. BOOK 2
PP. 67-70

GASEOUS EXCHANGE
RESPIRATION

Diseases of the respiratory system.
Introduction ? Definition and importance of respiration.

By the end of the lesson, the learner should be able to:
To state the causes, symptoms and prevention of respiratory diseases.
By the end of the lesson, the learner should be able:
To define respiration.
To explain significance of respiration.

Discuss cause, symptoms and prevention of whooping cough TB, bronchitis, etc.
Q/A: Definition

Brief discussion of significance of respiration.

Resource person.
text book

K.L.B. BOOK 2
PP. 67-70
K.L.B. BK 2
PP. 73-74

RESPIRATION

Burning food.

By the end of the lesson, the learner should be able to:
To describe an experiment investigating the gas given off when food is burnt.

Teacher demonstration: Burning a food sample.
Testing for the gas evolved during combustion.

text book

K.L.B. BK 2
PP. 73-74

RESPIRATION

The mitochondrion.

By the end of the lesson, the learner should be able to:
To state functions of mitochondrion in respiration.

Drawing structure of the mitochondrion.
Explain function of the mitochondrion.

Wall charts- The mitochond-rion

K.L.B. BK 2
P. 74

RESPIRATION

Aerobic respiration.

By the end of the lesson, the learner should be able to:
To explain phases of aerobic respiration.
To state difference between aerobic and anaerobic respiration.

Detailed discussion.
Writing down equations of food breakdown.

text book

K.L.B. BK 2
PP.74-76

RESPIRATION

Anaerobic respiration.
Oxygen ?debt?.

By the end of the lesson, the learner should be able to:
To describe anaerobic respiration.
To explain the term ?oxygen debt?.
To explain the effect of ?oxygen debt? on the amount of energy released during respiration.

Observe set up experiments.
Detailed discussion punctuated with probing questions:

Probing questions.

Detailed discussion.

Glucose
Yeast
Thermometer

text book

K.L.B. BK 2
P.77
K.L.B. BK 2
P.78

RESPIRATION

Applications of anaerobic respiration.

By the end of the lesson, the learner should be able to:
To explain applications of anaerobic respiration.

Q/A: Products of fermentation process.
Listing down various applications of anaerobic respiration.

text book

K.L.B. BK 2
P. 79

RESPIRATION

Respiratory substrates & respiratory quotient.

By the end of the lesson, the learner should be able to:
To identify respiratory substrates in the body.
To define respiratory quotient.
To calculate R.Q.

Brief discussion/ explanations.

Exposition of definition and its significance.
Problem solving.

text book

K.L.B. BK 2
P. 79

RESPIRATION

Rate of respiration.

By the end of the lesson, the learner should be able to:
To state and explain factors affecting rate of respiration.

Detailed discussion and explanations.

text book

K.L.B. BK 2
PP. 80-81