Materials that are Transported in Plants and Animals

Subject 

Biology

Topic 

Materials that are Transported in Plants and Animals

 

Class :

SSS 2

Term :

First Term

Week :

Week 3

Educational Teaching Materials :

• Pictures of plants and animals
• Pattern alimentary canal of animal

 

Reference 

• Scheme of Work
• On-line Info
• Textbooks
• Workbooks

Earlier Tutorials 

The pupils have earlier information on

CLASSIFICATION OF MAMMALS BASED ON THEIR DIET

that was previously taught as a topic before this particular lesson

 

Behavioural Goals :  On the finish of the lesson, the learners will be capable to

1. Definition of Transport Systems
2. Say The Need for Transportation
3. Mention Some Materials that are Transported in Plants and Animals
4. Explain The Media of Transportation
5. The Need for Substance to Move Over Greater Distances
6. Transport Systems in Large Organisms
7. Functions of the Blood
8. Transport Tissues in Plants and Animals

 

 

CONTENT

1. Definition of Transport Systems
2. The Need for Transportation
3. Materials that are Transported in Plants and Animals
4. Media of Transportation
5. The Need for Substance to Move Over Greater Distances
6. Transport Systems in Large Organisms
7. Functions of the Blood
8. Transport Tissues in Plants and Animals

 

Definition of Transport Systems

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

The 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 move mineral salt and water from the root to the stems and leaves.

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, estrogen etc) and other materials.
6. Antibodies

Materials that are Transported in Plants

Materials that are transported in plants include:

1. Water
2. Manufactured food
3. Excretory products
4. Hormones
5. Mineral salts
6. Oxygen

Media of Transportation

In all organisms, a liquid or fluid is the medium of transportation of materials. It includes blood, lymph and tissue fluid in most animals; latex or cell sap in many plants and cytoplasmic fluid in small organisms such as protozoan, protists and coelenterates.

Some of the media of transportation include:

1. Blood and lymph in the vertebrates.
2. Cytoplasm in unicellular organisms.
3. Cell sap or latex in most plants.
4. Body fluid in vertebrates.
5. Closed and open circulations.

The Need for Substance to Move Over Greater Distances

Following the explanation, because small organisms have large surface area to volume ratio, the movement of materials in and out of them can be done efficiently by diffusion. In multicellular organisms with a small body surface relative to their large volume, diffusion is inadequate for the exchange of metabolic materials within their body and between them and their external environment. This is because large quantities of nutrients and waste products have to be transported over long distances to and from their numerous body cells.

In order words, as the SA/V ratio in multicellular organisms decrease with increasing sizes, the rates at which substances diffuse into and out of their cells decreases. Hence, most multicellular organisms have developed transport system. The transport system in animals is very similar to the city transport or water system. There is orderliness, and everything is highly organized.

Transport Systems in Large Organisms

In large and more complex organisms, transport system is necessary because;

1. The ratio A/V diminishes, and so the rate at which nutrients and other substances diffuse decreases. This implies that small organisms have large surface area in relation to their volume (i.e., per unit of volume) than large organisms. This could be illustrated by considering three cubes of 1mm, 6mm, and 10mm. Using, Ratio = SA/V.  You will discover that the ratio of the smallest cube is =6unit, followed by 1unit, and 0.6unit respectively.
2. Substances have to move greater distances.

In plants, materials for transportation include; water, mineral salts, manufactured food and carbon (iv) oxide.

Materials for transport in animals include; digested food, vitamins, mineral salts, oxygen, carbon (iv) oxide, urea, salts, hormones, water and antibodies.

Functions of the Blood

There are several functions performed by the mammalian blood. These functions are grouped into three viz:

1. Transport

(i) It carries oxygen from the lungs to the tissues and carbon (iv) oxide from the tissues to the lungs for excretion.

(ii) It carries digested foods from the gut to the various parts of the body.

(iii) It carries nitrogenous waste products from the tissues to the kidneys, which get rid of them.

(iv) It carries hormones and antibodies from one part of the body to another.

2. Protection

(i) It protects the body from the attacks of germs, which cause diseases, by killing germs.

(ii) It protect the body from excessive bleeding, by clotting when a body tissue is cut or        wounded

3. Regulation

(i) It helps to regulate the quantity of water in the tissues (osmoregulation).

(ii) It helps to regulate the quantities of the various chemical materials in the tissue (homoeostasis).

(iii) It helps to keep the body temperature fairly constant by distributing heat evenly around the body.

In small organisms like Amoeba, and paramecium, cytoplasm which is fluid part of the organism is used for transportation of food and other materials in and out of the organisms.

In many plants, the medium of transportation of materials is the latex or cell sap. The cell sap is made up primarily of water, dissolved materials like synthesised foods, growth substances and inorganic salts. The sap is transported to all the parts of a plant through the phloem tissue. Different plants have latex (cell sap) of different colours. For example, the latex of rubber plant cassava (manihot) is white. A few plants have red or colourless latex.

Structure and Function of the Blood

The mammalian blood comprises four main components;

1. Plasma
2. Red corpuscles
3. White corpuscles
4. Platelets

1. Plasma: The plasma is a pale yellow liquid made of mainly of water (about 90%), with many substances dissolved in it. These include digested food, mineral salts, vitamins, hormones, dissolved oxygen and excretory products such as urea and carbon (iv) oxide. The plasma also contains large molecules, the plasma proteins, such as fibrinogen, which assist in the clothing of blood in damaged tissues.

2. Red corpuscles or erythrocytes: They are tiny, biconcave, disc-like cell without any nucleus in adult mammals. They contain a red pigment-haemoglobin, a protein that contains iron. This enables the red blood corpuscles to readily combine with oxygen in area of high oxygen concentration (i.e., the alveoli of lungs) to form oxyhaemoglobin. This is the form in which oxygen is carried to all body tissues. They also readily give oxygen in places where the oxygen concentration is low (e.g., all the tissues except those near the alveoli). Erythrocytes are synthesised in the red bone marrows of sternum, ribs and vertebrae. There are about 51/2 million of them in a cubic centimetre of blood. They live for about 120 days and are destroyed in the liver or spleen.

Erythrocytes

Erythrocytes, or red blood cells, are the primary carriers of oxygen to the cells and tissues of the body. The biconcave shape of the erythrocyte is an adaptation for maximizing the surface area across which oxygen is exchanged for carbon dioxide. Its shape and flexible plasma membrane allow the erythrocyte to penetrate the smallest of capillaries.

3. White corpuscles or leucocytes: There are many types of white corpuscles all of which have nuclei. They are made in the red bone marrow, the lymph node or the spleen. They live for many months. Those that are irregular in shape, i.e., the phagocytes, are commonest. They are large with lobed nuclei. Like the Amoeba, they have pseudopodia and are able to pass through the walls of the capillaries into the tissue fluid. In the lymphatic system, they ingest bacteria, virus and dead cells, and help in preventing diseases. The ingestion of materials is called phagocytosis and hence such white corpuscles are called phagocytes. Those that produce antibodies are called lymphocytes and are produced in the lymph glands. They produce chemicals called antibodies, which stick to the surface of germs and kill them. White corpuscles are fewer than the red corpuscles. There are about 5000 of them in a cubic millimetre of blood.

Lymphocyte

Scanning electron micrograph of a normal T lymphocyte. Lymphocytes are specialized white blood cells whose function is to identify and destroy invading organisms such as bacteria and viruses. Some T lymphocytes directly destroy invading organisms, whereas other T lymphocytes regulate the immune system by directing immune responses.

1. Platelets: These are tiny, irregularly-shaped particles formed in the red bone marrow. They lack nucleus. In damaged tissues, they break down and librate an enzyme, which catalyses the first of a series of reactions, fibrinogen, a blood protein, is converted to threads of fibrin, which form a mesh that plugs the wound. This stops the bleeding.

Thrombocytes and Clotting

Thrombocytes, or platelets, are the smallest cellular component of blood. They circulate inactivated, about 250,000 per cubic mm of blood, until they come into contact with a damaged blood vessel. At this point, the platelets form a clump, adhering to each other and to the blood vessel wall. They secrete chemicals that alter a blood-borne protein, fibrinogen, so that it forms a mesh of fibers at the damage site. A clot forms when platelets and red and white blood cells become trapped in the fibers. Blood clotting begins within seconds of injury. The same process can produce unwelcome clots in undamaged blood vessels.

Transport Tissues in Plants and Animals

Tissues used for transportation are:

1. Arteries,
2. Capillaries,
3. Veins, and
4. Vascular bundles (in plants)

Structure of Arteries

1. All Arteries carry oxygenated blood from the heart to the body tissues, except pulmonary arteries
2. These are wide vessels that generally transport blood from the heart to the limbs and organs.
3. There is one artery to each of the organs of the body.
4. They are muscular, thick walled and elastic and are able to withstand the high pressure caused by the heartbeat.
5. The arteries branch in the organs to form arterioles.
6. The arterioles also branch repeatedly to form a network of blood capillaries, which permeate every living cell of the body.

Structure of Capillaries

1. These are tiny vessels with very thin walls, which are often one cell thick.
2. Their walls allow water and dissolved substances, except proteins, to pass in and out of them.
3. The capillaries branch within the tissues.
4. Through their thin walls, dissolved food and excretory products are exchanged with the tissues around them.
5. The capillaries network is so dense that no living cell is far from food and oxygen supplies.
6. The capillaries rejoin to form veins.
7. Through the capillaries network, blood flows from the arterial end to the venous end.

 

Structure of Veins

1. All veins carry de-oxygenated blood from the body tissues to the heart, except pulmonary vein.
2. They are wider and have thinner walls than arteries.
3. The veins branch from the organs to form venules.
4. They have valves at intervals, which allow blood to flow in one direction from other organs towards the heart.

Structure of Vascular Bundles

1. Vascular bundles consist mainly of xylem and phloem tissues. But in the root and stems of dicotyledons, a layer of cambium cells exist between the xylem and phloem tissue.
2. Xylem transports water and mineral salts while Phloem translocates manufactured food from the leaves to where it is stored.
3. Vascular bundles are found in the roots, stems and leaves of flowering plants.
4. Vascular tissues are grouped together in bundles within the plant body.
5. The vascular tissues of plants are made up of a network of long tubes called vascular bundles.
6. They are called veins in the leaves.

 

 

 

Presentation

The subject is offered step-by-step

 

Step 1:

The category trainer revises the earlier matters

 

Step 2.

He introduces the brand new subject

 

Step 3:

The category trainer permits the pupils to present their very own examples and he corrects them when the wants come up

 

 

Conclusion :

 

The category trainer wraps up or conclude the lesson by giving out brief observe to summarize the subject that she or he has simply taught.

The category trainer additionally goes spherical to guarantee that the notes are properly copied or properly written by the pupils.

She or he does the required corrections when and the place  the wants come up.

 

 

EVALUATION

1. Define transport systems.
2. State the functions of the blood.
3. Highlight the structure of the blood and functions
4. explanations on feeding mechanisms.

 

Conclusion 

The subject wraps up the topic by giving the learners a comprehensive note and he or she makes sure that the learners copy the notes correctly . He or she marks the notes and he does the necessary corrections