BIOLOGY LESSON NOTE ON TRANSPORT SYSTEM

Topic: Transport   System

Instructional  Materials: Models, specimen, pictures

Aim of the Lesson: To help the learner understand the transport system

Anticipated Problems: Because of advancement in class, most themes might be new to the learner and might result to difficulty in understanding.

Possible Solution: The teacher explains the concept in details using illustrations and real objects.

Content Objectives: By the of the lesson, learner should be able to;

1. Define  of transport system
2. State the need for transport system
3. Explain transport system in lower organism
4. List the materials for transport
5. Explain the media for transportation of materials
6. Explain the mechanism of transportation in some organism and Unicellular organism and Simple multicellular organism
7. Explain transport system in man 

Time Table fit/ previous knowledge: The learners learnt about the digestive system in their previous class.

Set Induction: The teacher asks the learner to observe the picture on the wall.

Differentiation Method/Multiple Intelligence: The teacher uses different teaching technique such as discussion, role playing, questioning and use of picture to ensure all the learner benefit from the lesson.

Transport system

Transportation is the movement of metabolic substances from various parts of the organism where they are produced or obtained to the parts where they are used, stored or removed from the body.

Transport system involves all the tissue and organs responsible for the movement of metabolic substances from various parts of the organism.

NEED FOR TRANSPORTATION

1. It aids in the removal of metabolic waste e.g carbon dioxide, water and

urea

2. It helps to move hormones in plants and animals from where they are produced to areas of need.

3. It helps transport essential materials in organisms for metabolic process e.g nutrients, oxygen and water.

4. In plants, transport is necessary to mineral salt and water from the root to the stems and leaves.

TRANSPORT IN LOWER ORGANISM

In lower or unicellular such as amoeba, paramecium, euglena etc.  The surface area yo volume ratio (SA/V) of the body is large. As a result, essential nutrients like food, oxygen and water as well as excretory product e.g water, carbon dioxide etc move in and out of the body by diffusion. Also some simple multicellular animals such as tapeworm are flat and thin in structure. 

MATERIALS THAT ARE TRANSPORTED IN ANIMALS

The materials transported in animals

include:

1. Water

2. Digested foods (vitamins, amino acids, mineral salts, fatty acids glycerol)

3. Gases (oxygen, carbon-dioxide)

4. Excretory products (urea, carbon- dioxide, excess salt)

5. Hormones (adrenalin, insulin, oestrogen etc) and other materials.

6. Antibodies

7. mineral salt

8. sugar

9. vitamin

10 fatty acid and glycerol

MATERIALS THAT ARE TRANSPORTED IN PLANTS

These include:

1. Water

2. Manufactured food

3. Excretory products

4. Hormones

5. Mineral salts

6. Oxygen

7. Glucose

8. Amino acid

9. Lipids

MEDIA OF TRANSPORTATION

In all organisms, a liquid or fluid is the medium of transportation of materials. Generally, there are four major media of transportation, which are

1. Cytoplasm
2. Cell sap or latex
3. Blood
4. Lymph

Cytoplasm: is used as the medium of transportation of materials in lower unicellular organism such as amoeba and paramecium

Cell sap or latex: cell sap or latex is used as the medium for transportation of materials in plant

Blood: the blood is powerful medium of transportation of materials in most animals especially vertebrates.

Lymph: Lymph is one of the media of transportation in higher animals. It is a fluid similar in composition to tissue fluid.

Mechanism of transportation in unicellular organism

In unicellular organism, the continuous streaming movement of the cytoplasm circulate materials within one-cell body

Mechanism of transportation in simple multicellular organism

Hydra: in hydra, movement of the gut wall draw water into the gut and cause digested food and oxygen within it to circulate.

Flatworm: In flatworm, the gut branches extensively throughout the body. These features enable sufficient food and oxygen to diffuse into the body cell.

Insect and mollusks: They have open circulatory system. In the system, the heart pumps blood out into a blood vessels which branches and open into the spaces in the body cavity called HEAMOCELS

TRANSPORT SYSTEM IN MAN

Transport system in man is made possible by blood and lymph which represent the media of transport in man.

Composition and structure of the blood

The blood is a tissue in a fluid form. Blood is made up of two major components

1. The plasma which is liquid
2. The blood cell or corpuscles which are solid

Plasma

is a pale yellow liquid which is largely made-up of 90% water and many  dissolved substances like proteins, waste materials, digested food, gases, hormones and salts.

Blood cell or corpuscles

There are tree types of blood cells. They are

1. The red blood cell (Erythrocyte)
2. The white blood cell (Leucocyte)
3. The blood platelet (Thrombocyte)

 

RED BLOOD CELL: are bi-concave, flat and circular cells without a nucleus in the mature cells. The cells contain oxygen-carrying, red pigment hemoglobin which is responsible for the color of the cells. They are formed in the bone marrow of adults.

FUNCTION: they transport oxygen from the lungs to the body cells.

WHITE BLOOD CELLS: are larger than red blood cells and are nucleated.

They are formed in lymph nodes and bone marrow. They are lymphocytes and phagocytes.

FUNCTION: they defend the body against diseases by getting rid of foreign bodies.

PLATELETS: these are irregular, non-nucleated and tiny cell fragments formed in large bone marrow cells. 

FUNCTION: they prevent excessive loss of blood by the formation of the blood clot when there is a cut. This is known as clotting.

         STRUCTURE OF THE BLOOD VESSELS

The circulation of blood in mammals is made possible with the aid of blood vessels and heart.

Blood vessels are the tube within the body through which the blood flows away or to the heart. There are three major types of blood vessels. They are arteries vein and capillaries 

Differences between arteries and vein

ARTERY	VEIN
They have a thick, muscular and elastic wall	They have a fairly thick and slightly elastic wall
They do not contain valves (except semilunar valves in the aorta  and pulmonary artery)	They contain valves
Transport blood away from the heart	Transport blood to the heart
Contain blood with high  pressure	Contain blood with low pressure
Always contain oxygenated blood    (except pulmonary  artery)	Always contain deoxygenated blood (except pulmonary vein)

CAPILLARIES: Arteries branch to form arterioles while veins branch into venules. In the organs, the arterioles connect with the venules by a network of blood vessels known as the capillaries. The walls of capillaries are a cell thick and they make available a large surface area for the exchange of materials   between the blood and the body of cells. 

Assessment plan. The teacher uses the following to assess the learners

Class work

Name the media of transportation

Name five materials each in plant and animal for transportation

Home work

Draw the structure of the cytoplasm

Multiple choice questions.

1. Medium of transportation of materials in lower unicellular organism such as amoeba and paramecium is

1. Cytoplasm
2. Cell sap or latex
3. Blood
4. Lymph

2. Medium for transportation of materials in plant is

1. Cytoplasm
2. Cell sap or latex
3. Blood
4. Lymph

3. Medium of transportation of materials in most animals especially vertebrates.

1. Cytoplasm
2. Cell sap or latex
3. Blood
4. Lymph                                                                 

4. Another name for platelet is

1. Thrombocyte
2. Leucocyte
3. Plasma
4. Erythrocyte

5.   Another name for white blood cell is

1. Thrombocyte
2. Leucocyte
3. Plasma
4. Erythrocyte

6. Another name for red blood cell is

                     a.         Thrombocyte

                     b.         Leucocycte

                      c.         Plasma

                     d.         Erythrocycyte 

Evaluation

1. Define  of transport system
2. State the need for transport system
3. Explain transport system in lower organism
4. List the materials for transport
5. Explain the media for transportation of materials
6. Explain the mechanism of transportation in some organism and Unicellular organism and Simple multicellular organism
7. Explain transport system in man 

Glossary

Media: Pathway or channel

Lymph:  The fluid that flows through the lymphatic system.

Conclusion: Transport system involves all the tissue and organs responsible for the movement of metabolic substances from various parts of the organism.