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

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

Teacher demonstration: Test for the gas evolved.
Discuss observations.
Detailed discussion.
Drawing diagrams.
Detailed discussion.
Observe number of stomata of prepared slides of hydrophytes and xerophytes.
Discuss the observations.

Gas jar,
Glass funnel,
Water plant,
Beaker.
text book
text book
Prepared slides of hydrophytes and xerophytes.

K.L.B. BOOK 2
P. 49
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.
Breathing in insects.

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

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

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

text book
Live specimens of insects,
Hand lenses,
Boiling tubes.

K.L.B. BOOK 2
PP. 53, 54
K.L.B. BOOK 2
P. 56

GASEOUS EXCHANGE

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

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.
To explain the mechanism of gaseous exchange in a frog.

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

Live specimens of insects.

A gill of a fish.
text book

K.L.B. BOOK 2
P. 56

GASEOUS EXCHANGE

Gaseous exchange in mammals.

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.

Discuss at length man?s respiratory system.

Wall chart- Respiratory system in man.

K.L.B. BOOK 2
P. 59

GASEOUS EXCHANGE

The structure of the lungs.
Inhalation.
Exhalation.

By the end of the lesson, the learner should be able to:
To explain adaptations of the lungs to their functions.
To describe the process of inhalation in man.
To describe the process of exhalation in man.

Drawing labeled diagrams coupled with explanations.
Showing movements of ribs during inhalation.
Explain the inhalation mechanism.
Showing movements of ribs during exhalation.
Explain the exhalation mechanism.

Wall charts- Structure of lungs.
Chart / model of a rib cage.

K.L.B. BOOK 2
P. 60-1
K.L.B. BOOK 2
PP. 61-62

GASEOUS EXCHANGE

Thoracic cavity model.
Gaseous exchange in an alveolus.

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.
To describe gaseous exchange in an alveolus.
To explain regulation of breathing in man.

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

Thoracic cavity model.
text book

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

GASEOUS EXCHANGE

Rate of breathing in man.

By the end of the lesson, the learner should be able to:
To state and explain briefly factors affecting the rate of inhalation / exhalation processes.

Discussion and explanations.

text book

K.L.B. BOOK 2
P. 63

GASEOUS EXCHANGE

Intercostal muscles.
Inhaled and exhaled air.

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

To test for CO2 in the air we inhale/ exhale.

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

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

Lime water, rib cage model.
Lime water.

K.L.B. BOOK 2
P. 66
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

EXCRETION AND HOMEOSTASIS

The mammalian skin.
The lungs.

By the end of the lesson, the learner should be able to:
Draw and label the structure of the mammalian skin.
To describe functions of parts of the mammalian skin.
To explain the role of lungs as excretory organs.

Exposition and discussion.

Permanent slides of mammalian skin.
Chart/ model- Mammalian lungs.

K.L.B. BK 2
PP. 86-87

EXCRETION AND HOMEOSTASIS

The kidneys structure.
The nephron.

By the end of the lesson, the learner should be able to:
To describe the external structure of kidney.
To describe the internal structure of the kidney.
Describe features of the nephron.

Observe external features of a kidney.
Observe internal drawing and labeling of the kidney.
Discuss features of the nephron.
Draw structure of the nephron.
Label the diagram.

Wall-Charts?internal organs of a kidney.

Chart?Kidney nephron.

K.L.B. BK 2
PP. 89-90

EXCRETION AND HOMEOSTASIS

Urine formation.
The loop of Henle.

By the end of the lesson, the learner should be able to:
To explain formation of urine.
To explain the function of the loop of Henle; and how it?s adapted to its function.
To discuss the role of ADH in determination of concentration of urine.

Detailed discussion.
Discussion and explanations.
Probing questions.

chart
Chart-
The nephron.

K.L.B. BK 2 PP 90

EXCRETION AND HOMEOSTASIS

Kidney diseases and disorders.
The Liver.
Deamination.

By the end of the lesson, the learner should be able to:
To name kidney diseases and disorders and state methods of prevention and / treatment.
To draw and label a diagram of the liver.
To explain the function of the liver in deamination.

Discussion and Explanations.
Drawing and labeling diagram of the liver.
Probing questions.
Discussion

text book
Chart-Structure of the liver

K.L.B. BK 2 PP 92

EXCRETION AND HOMEOSTASIS

Other functions of the liver.
Liver disorders.
Homeostasis.
The feedback mechanism.
The hypothalamus.

By the end of the lesson, the learner should be able to:
To state and explain other functions of the liver.
To name and discuss kidney disorders.
To identify methods of preventing and treating these disorders.
To define the concepts of internal environment and homeostasis.
To differentiate between positive and negative feedback and state their roles in maintaining the desirable point.
To explain the role of hypothalamus in thermoregulation.

Probing questions.
Discussion
Exposition and discussion.
Schematic representation of feedbacks.
Exposition and discussion.
Exposition and detailed discussion.

text book
Chart-
Schematic diagram of feedback mechanism
text book

K.L.B. BK 2 PP 95-96
K.L.B. BK 2 PP 97-98

EXCRETION AND HOMEOSTASIS

The skin and thermoregulation.
Blood vessels and their functions in thermo-regulation.

By the end of the lesson, the learner should be able to:
To explain the function of the skin in thermoregulation.
To explain the adaptation of blood vessels and their function in thermo-regulation.

Exposition and discussion.
Drawing schematic diagrams.

text book

K.L.B. BK 2 PP 98

EXCRETION AND HOMEOSTASIS

Homeostatic behavioral activities.
Osmoregulation.

By the end of the lesson, the learner should be able to:
To state and explain various homeostatic behavioral activities.
To describe water and salts balance in the body.

Discussion on control of body temperature.
Probing questions.
Detailed discussion.

text book,video
text book

K.L.B. BK 2 PP 99

EXCRETION AND HOMEOSTASIS

Blood sugar.
Diabetes.

By the end of the lesson, the learner should be able to:
To discuss effects of insufficient/ excess sugar in the blood.
To explain regulation of blood sugar.
To distinguish diabetes mellitus from diabetes inspidus.
To identify simple symptoms of diabetes mellitus and diabetes inspidus.

Detailed discussion.
Detailed discussion.
Probing questions.
Topic review.

text book

K.L.B. BK 2 PP 101-102