TRANSPORT SYSTEM IN MAN


TRANSPORT SYSTEM IN MAN

Transport system in mammals especially man provides an efficient way of distribution of materials within the body. This is made possible by blood and lymph which represent the media of transportation in man.

composition and structure of blood

man has about 5-6 litres of blood. Blood is made up of two major components: (i) the blood cell or corpuscles which are solid and (ii) the plasma which is liquid

Blood cells or corpuscles

There are three types of blood cell or corpuscles. These are:
(a) Red blood cells (erythrocytes)
(b) White blood cells (leucocytes)
(c) Blood platelets (thrombocytes)

RED BLOOD CELLS (ERYTHROCYTES)

The red blood cells also called erythrocytes are small, round and biconcave or disc like in shape. They have no nucleus. One cubic litre of blood has about 5 ½ million red blood cells. Their normal life span is about 120 days (4 months) before they are destroyed by the liver.







The red blood cells are mainly produced by the bone marrow. The red colour of the cells is due to the presence of iron compound called haemoglobin.
FUNCTIONS OF RED BLOOD CELLS
1. The pigment, haemoglobin in red blood cells helps to transport oxygen from the lungs to the body cells. Haemoglobin combines readily with oxygen to form oxyhaemoglobin in the lungs.
2. They transport small quantities of carbon dioxide.
3. They take part in blood clotting.
WHITE BLOOD CELLS (LEUCOCYTES)
The white blood cells which are also called leucocytes are irregular and amoeboid in shape. They are large, colourless and contain nucleus. They are larger than the red blood cells in diameter and fewer in number than the red blood cells, i.e. about 5,000—10,000 of them exist in a cubic mililitre of blood. They are made in the red bone marrow, the lymph nodes or the spleen. They can live for many months.
There are two types of white blood cells:
i. Phagocytes: the phagocytes are found in the lymphatic system where they ingest bacteria, viruses and dead cells and help in preventing diseases. The ingestion of materials is called phagocytosis, and hence such white corpuscles are called phagocytes.
Lymphocytes: the lymphocytes produce antibodies and are made in the lymph glands. They produce chemicals called antibodies which stick to the surface of

ii. germs and kill them.

FUNCTIONS OF WHITE BLOOD CELLS

1. The white blood cells help to defend the body against diseases by ingesting the bacteria and virus that cause diseases.
2. They produce antibodies or immunity for the body.

BLOOD PLATELETS (THROMBOCYTES)

The blood platelets also called thrombocytes, are tiny, irregular cell fragments without nucleus. They are produced in the red bone marrow. Platelets are fewer in number and smaller in size than the red blood cells, i.e. 250,000—400,000 per mm3 of human blood/

FUNCTIONS OF BLOOD PLATELETS


Platelets aid in the clotting of blood.

plasma

Plasma is the liquid component of blood. It is a pale yellow liquid, mainly of water (about 90% water). Many substances are dissolved in it including plasma proteins, antibodies, hormones, enzymes, gases, digested food, salts and other waste products.
FUNCTIONS OF PLASMA
1. Plasma transport the end products of digestion or digested food especially glucose and amino acids.
2. It transports waste products, hormones, heat from very actively respiring tissues, carbon dioxide, urea or waste materials, antibodies, amino acids and mineral salts.
3. It participates in blood clotting.
4. It transports oxygen.

Lymph

The lymph is a colourless liquid associated with the lymphatic system. It is a fluid similar in composition to the tissue fluid but contains extra lymphocytes. It has no red cells.

The lymph returns fluid to the main vein through openings in the subclavian (left jugular) vein below the neck. Movement of the lymph is enhanced by the action of muscles. Lymph moves through lymph vessels, e.g. lacteal. Some swellings do exist in groups along the lymph vessels especially in the neck, groin and armpit called lymph nodes. The lymph nodes are where lymph passes through to be made pure before entering into the blood stream. The lymphatic system is second to the circulatory system, but unlike the circulatory system it ends blindly.

functions of the lymph

1. Body defence: the lymph aids body defense. The lymph nodes produces white blood cells. Disease causing micro-organisms, foreign particles etc. found in the lymph are filtered out in the lymph nodes and engulfed by phagocytes.
2. Absorption of fatty acids and glycerol: the lymphatic system such as the lateal is associated with the absorption of fatty acids and glycerol.

Functions of the blood

The mammalian blood performs a number of functions which include:
1. Transport of oxygen: the blood transports oxygen with the aid of a pigment in the red blood cells called haemoglobin. The oxygen is combined with the haemoglobin to form oxyhaemoglobin. When haemoglobin is dull red, oxyhaemoglobin is said to be oxygenated and it is dark red. As oxygenated blood circulates round the body and reaches the cells and tissues oxyhaemoglobin dissociates, releases oxygen and reverts to haemoglobin which is carried back to the lung to be re-oxygenated.
2. Temperature regulation: heat produced in the liver and the muscles are distributed throughout the body thereby keeping the body temperature almost uniform.
3. Transportation of digested food: digested food substances like amino acids, glucose, fatty acids, and glycerol are transported from the villi of small intestine through the blood to all the cells and tissues within the body, either for use or storage.
4. Transportation of excretory products: excretory products such as carbon dioxide, water and urea are transported by blood from the cells that produce them to the various excretory organs like lungs, skin, liver and kidney for elimination.
5. Transportation of hormones: hormones are transported through the blood from the area of production to the target organs where they act.
6. Defence against infection by microbes or pathogens.
7. Production of antibodies: antibodies are produced by white blood cells and are transported by the blood round the body. They help in the defence of the body by destroying pathogenic organisms or their harmful products.
8. Blood clotting: the platelets in the blood are able to initiate the process of blood clotting when an injury is sustained.
9. Transport of water: water which forms about 90% of the blood is transported by the blood to the various cells for various metabolic activities. The level of water in the body is always maintained by the blood.
10. Transportation of mineral salts: mineral salts such as sodium are transported from one part of the body to another through the blood.

Body defence functions of the blood

The blood is able to defend the body against disease causing organisms such as bacteria and viruses in four major ways:
1. Clumping: in this process, the lymphocytes, a type of white blood cells produce chemical substances or antibodies which react with the surface of bacteria or the antigen which cause the bacteria or antigen to clump with antibody.
2. Neutralization: in this process, the white blood cells also produce antitoxins which neutralize the toxins produced by pathogenic agents thereby making them harmless.
3. Engulfing: phagocytes, another type of white blood cells engulf the disease causing organisms or pathogens and digest them.
4. Clotting: the clotting of blood through the aid of the blood platelets prevent germs or diseases causing organisms from entering the body.








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process of blood clotting and functions of antibodies


HERE YOU WILL FIND EVERY AVAILABLE TOPIC ABOUT AGRICULTURAL SCIENCE AND BIOLOGY AND LINK TO THEIR VARIOUS SOURCES.







48. BIOTIC FACTOR AND AGRICULTURAL PRODUCTION
49. PESTS
50. BIRDS
51. DISEASES
52. SOIL MICRO-ORGANISMS
53. SOIL PH
54. ROCK FORMATION
55. IGNEOUS ROCK
56. SEDIMENTARY ROCKS
57. METAMORPHIC
58. SOIL AND ITS FORMATION
59. FACTORS OF SOIL FORMATION
60. LIVING ORGANISM

80. SANDY SOIL
83. SOIL TEXTURE
84. IDENTIFICATION OF SOIL TYPES THROUGH EXPERIMENTS
85. RETENTION OF WATER BY VARIOUS SOIL TYPES
86. DETERMINATION OF SOIL PH REACTION
87. COLORIMETRIC DETERMINATION OF SOIL PH LEVEL





88. PH SOIL TEST
89. PLANT NUTRIENTS
90.
MACRO NUTRIENTS IN GENERAL
112. THE MAINTENANCE OF SOIL FERTILITY
113. CROP ROTATION
114. APPLICATION OF ORGANIC MANURES
115. FARM YARD MANURE
116. APPLICATION OF INORGANIC MANURE
117. LIMING
118. FARMING PRACTICES
119. BUSH BURNING AND CLEARING
121. FERTILIZER APPLICATION

HOW SOIL AFFECT THE VEGETATION OF A PLACE OR ENVIRONMENT


HOW SOIL AFFECT THE VEGETATION OF A PLACE OR ENVIRONMENT

Soil is define as the uppermost layer of the earth crust
which provides support and nutrient for growth.
The soil is also a habitat for some animal species.
Before we look at the effect of soil on types of vegetation, we have to know what constitute soil. So there are three major types of soil, they are
a. Sandy soil
b. Loamy soil
c. Clay soil
Each of these types of soil varies in their ability to retain water necessary for plant and vegetative growth.
The types of soil found in a place can be a mixture of one or more
of the various soil types.
So let us take a proper look at the types of soil and they affect the vegetation of an environment. Here








1.

THE EFFECT OF SANDY SOIL ON VEGETATION

SANDY SOIL
A soil is to be sandy if the sand particles contained in the sample of soil is high. The particles sand are mainly quartz, and having a size of around 0.2mm to 2.0mm in diameter.
i. THE EFFECT OF SANDY SOL ON VEGETATION
Sandy soil is very low in plant nutrient due to the effect of leaching, which is the result of too much spaces between the pores of the particles, hence supports scanty vegetation or grassland. In other words, sandy soil is not good for farming activities.

2.

THE EFFECT OF CLAY SOIL ON VEGETATION

CLAY SOIL
A soil is said to be clayey if the proportion of clay in sample of soil is very high. The relative size of clay particle is less than 0.oo2mm in diameter. Clay soil is very heavy hence it very difficult to work on or cultivate.
I.

CLAY EFFECT ON PLANTS

Due to the fact that clay soil has the ability to retain water, it also has the capacity to retain little amount of plant nutrients. So clay soil can only support a few variety of plants such as savanna or shrubs and some luxuriant vegetation








3.

THE EFFECT OF LOAMY SOIL ON VEGETATION

Loamy soil is a mixture of sand and clay particles with high proportion of organic matter. Loamy soil is more fertile than either sandy or clay soil. Anytime we describe a portion of soil as sandy loam is means the soil contains more sand particle than loam, but if it is described as lay loam it means the proportion of clay is very high.
i.

EFFECTS OF LOAM ON VEGETATION

Loamy soil is by no doubt the best type of soil for farming activities as it contains large amount of plant nutrient hence it supports plant life effectively


WHAT ARE THE FACTORS AFFECTING WATER HOLDING CAPACITY OF THE SOIL?


Factors that may affect water retention capacity of soils are but not limited to the following

1.

ORGANIC MATTER CONTENTS:

the organic matter contents of the soil affect the rate at which water is retained. Loamy soil which rich in organic materials has more water retention capacity than sandy soil.


2.

SIZE OF SOIL PARTICLES:

sizes of soil particle also affects the soil ability to retain water. The smaller the particles, the higher the rate of water retention. So the clay soil has a higher capacity of water retention because of its fine and small particles.


3.

SOIL TEXTURE:

the soil texture, which is the degree of fineness or coarseness of the soil particles has a lot of influence on the water holding capacity of the soil. Clay soil has fine particles, hence it can retain water that a coarse sandy soil

4.

CLAY CONTENT OF THE SOIL:

the amount of clay present in any type of soil goes a long way to determine its water retention capacity. The higher the amount of clay in a soil sample, the higher the retention capacity of that soil

5.

MINERAL SALTS AND PH:

the amount of mineral salts in the soil determines the amount of water the soil can retain. High levels of mineral salts leads to high level of pH which supports high rate of water retention but when the pH is low, the mineral salts are disintegrated and subsequently lower the water retention capacity

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Important topics related to the above article

1. Recognizing living things
2. Biology as an enquiry in science
3. Branches of biology
4. Processes of methods of science
5. Usefulness of science
6. Living and non-living things

43. test for Food substances
44. Balanced diet and kwashiokor
food tests
45. Modes of nutrition
46. Feeding mechanisms in holozoic organisms
maintenance of teeth gum
47. Mammalian teeth
48. Dentition
49. Digestive enzymes
50. Meaning of ecology
causes of germs and diseases in humans
51. Local biotic communities or biomes in Nigeria
52. Major biomes of the world
53. Population studies
54. Ecological factors





INSECT-BORNE Disease AND TRANSMISSION METHOD


TYPES OF INSECT-BORNE DISEASE

1.

MALARIA AND THE MOSQUITO.

Malaria is a very dangerous disease which is known to have killed many people especially children. It usually starts as a fever when the body of the patient becomes hot.



This is followed with headache and pains in the back and joints such persons do not feel like eating. Later the patient shivers and becomes restless. He cannot sleep even when he tries to.

CAUSES OF MALARIA

Malaria is caused by parasitic germs carried by an insect called Anopheles mosquito. When the mosquito bites, it pierces the skin and sucks out the blood, read piercing and sucking insects here. During the blood sucking operation, the parasites which are present in the mosquito are introduced into the body of man. Here, the parasites increase in number. They destroy the red blood corpuscles of man and introduce poisonous substances into his blood it is this poisonous substances that cause feverishness. If the blood of a sick person or a person who has been attacked earlier is sucked by another mosquito, the parasites are taken out and probably injected into another person during another bite.






THE MOSQUITO

The mosquito is a small, thin fly. It has two wings and six long tiny legs. It also has a long piercing mouth. Mosquitoes breed in the water standing in cans, broken bottles, pots and any other kind of container. read about holozoic adaptation and mood of nutrition here
Adult mosquitoes live in the bush and in dark corners of the house. They are very active at night when most people are asleep.


It has four stages in its life cycle. These are the egg, the larva, the pupa and the adult.

THE EGG

The mosquitoes lays their eggs on the surface of stagnant or stationary water. The eggs are boat-shaped and have a floating apparatus called `floats’.

THE LARVA

In about four to seven days, the eggs hatch open and the larvae come out. The larva is a small, very active animal with a small head, big thorax and long segmented abdomen. It has a large number of brushes. At the tail end is a breathing tube. It lies on the surface of water.

THE PUPA

The larva changes into a comma-shaped pupa after about eight to eleven days. It has a big head with big eyes and breathing tubes.

THE ADULT

As previously described, it is a small insect which is active at night or in dark rooms. The female hums. It has a long piercing mouth and bushy feelers.

HOW TO PREVENT THE SPREAD OF MALARIA

Since malaria is caused by parasites carried by mosquitoes, it is best prevented by killing and destroying all stages of mosquitoes.
1. All adult mosquitoes should be killed by spraying houses with shelltox, DDT, and other insecticides.
2. All standing water in cans and empty containers should be drained away. Exposed water should not be allowed to remain for more than four days. Plants such as the cocoyam, banana and plantain should not be cultivated near houses, since between the leaves of these plants water will accumulate, thus, providing a suitable breeding place for mosquitoes.
3. The surface of stagnant pools which cannot be drained should be sprayed with oil. The oil spread over the water surface, prevents the larvae and the pupae of breeding mosquitoes from breathing. They will suffocate and die.
4. Quite occasionally we have large ponds of water. To prevent the breeding of mosquitoes, it is advisable to introduce some fish into such ponds. The fish will feed on the larvae and pupae.
5. Attacks by mosquitoes can be prevented by sleeping under mosquito nets. Where possible house should be mosquito-proof with mosquito netting of fine wires or muslin netting.
6. Malaria can be avoided by taking few tablets of some medicines regularly. Such medicines include: nivaquine, camoquin, daraprim, etc. The medicines destroy the malarial parasites as they enter the body and thus prevent them from causing any damage to the blood.

2.

SLEEPING SICKNESS

Sleeping sickness is very common in tropical Africa. In Nigeria, it is most common in the northern states. They attack cattle and horses.it also attacks man.
In man, sleeping sickness begins with a painful swelling in the skin. This is followed with fever, headache, pains and swelling of the neck. In later stages, the patient loses weight, becomes weak, dull, drowsy, and sleepy and may finally die.





CAUSES AND SPREAD

Sleeping sickness is caused by some parasitic germs called trypanosomes. This germs are spread by a fly known as tsetse fly. When the fly bites a patient the parasites are introduced into the skin. From the skin the parasites enter the blood from where they are sent to other parts of the body including the brain.

PREVENTION OF SLEEPING SICKNESS


1. In tsetse fly areas, all bushes near houses should be cleared.
2. Since tsetse flies breed in swamps by rivers and lakes, they can be eliminated or prevented from spreading if the bushes around these rivers and lakes are cleared for considerable distances.
3. It is advisable to wear clothes which cover most parts of the body.
4. Some chemicals such as DDT, dieldrin, etc. may be used to spray to kill tsetse flies.

3.

YELLOW FEVER

Yellow fever is a disease caused by a germ (virus) carried by Aedes mosquitoes.
Yellow fever usually starts with fever and headache. This is accompanied with loss of appetite, some pains and general weakness
In severe cases, however, the patient becomes very ill due to the attack of patient’s liver and kidneys by the disease germs. The patient becomes yellow and it is important to note that a large number of patients with severe attacks usually die.

PREVENTION OF YELLOW FEVER

1. All mosquitoes must be destroyed by draining stagnant water in tins and cans.
2. Houses should be sprayed regularly to kill adult mosquitoes.
3. All bushes near houses should be cleared.
4. Always sleep under mosquito-nets.


Please share if you find our article good and useful

Important topics related to the above article
1. Recognizing living things
2. Biology as an enquiry in science
3. Branches of biology
4. Processes of methods of science
5. Usefulness of science
6. Living and non-living things
7. Characteristics of living things





41. Uses of fibres to plants
42. Functions of supporting tissues in plants
43. test for Food substances
44. Balanced diet and kwashiokor
food tests
45. Modes of nutrition
46. Feeding mechanisms in holozoic organisms
maintenance of teeth gum

INSECT-BORNE DISEASE AND MALARIA PREVENTION


INSECT-BORNE DISEASE

1. MALARIA AND THE MOSQUITO.
Malaria is a very dangerous disease which is known to have killed many people especially children. It usually starts as a fever when the body of the patient becomes hot. This is followed with headache and pains in the back and joints such persons do not feel like eating. Later the patient shivers and becomes restless. He cannot sleep even when he tries to.







CAUSES OF MALARIA

Malaria is caused by parasitic germs carried by an insect called Anopheles mosquito. When the mosquito bites, it pierces the skin and sucks out the blood. During the blood sucking operation, the parasites which are present in the mosquito are introduced into the body of man. Here, the parasites increase in number. They destroy the red blood corpuscles of man and introduce poisonous substances into his blood it is this poisonous substances that cause feverishness. If the blood of a sick person or a person who has been attacked earlier is sucked by another mosquito, the parasites are taken out and probably injected into another person during another bite.
THE MOSQUITO
The mosquito is a small, thin fly. It has two wings and six long tiny legs. It also has a long piercing mouth. Mosquitoes breed in the water standing in cans, broken bottles, pots and any other kind of container.
Adult mosquitoes live in the bush and in dark corners of the house. They are very active at night when most people are asleep.


It has four stages in its life cycle. These are the egg, the larva, the pupa and the adult.
THE EGG
The mosquitoes lays their eggs on the surface of stagnant or stationary water. The eggs are boat-shaped and have a floating apparatus called `floats’.1. ENVIRONMENTAL FACTORS AFFECTING AGRICULTURAL PRODUCTION
2. DISEASES
3. 52. SOIL MICRO-ORGANISMS
4. ORGANIC MANURING
5. FARM YARD MANURE
6. HUMUS
7. COMPOST
8. CROP ROTATION
9. GRAZING AND OVER GRAZING
10. IRRIGATION AND DRAINAGE
11. IRRIGATION SYSTEMS
12. ORGANIC MANURING
13. FARM YARD MANURE
14. HUMUS
15. COMPOST
16. CROP ROTATION
17. GRAZING AND OVER GRAZING
18. IRRIGATION AND DRAINAGE
19. IRRIGATION SYSTEMS
20. INCUBATORS
21. MILKING MACHINE
22. SIMPLE FARM TOOLS
23. AGRICULTURAL MECHANIZATION
24. THE CONCEPT OF MECHANIZATION
25. PROBLEMS OF MECHANIZATION
26. SURVEYING AND PLANNING OF FARMSTEAD
27. IMPORTANCE OF FARM SURVEY
28. SURVEY EQUIPMENT
29. PRINCIPLES OF FARM OUTLAY

56. ESTABLISHMENT OF PASTURES
57. 201. FORAGE PRESERVATION
58. HAY SILAGE
59. FORESTRY IMPORTANCE OF FORESTRY 206. FOREST MANAGEMENT FOREST REGULATION DEFORESTATION AFFORESTATION
60. DISEASES AND PESTS OF CROPS

77. COCOA MIRIDS(CAPSIDS)
78. APHIDS
79. WHITE FLY SEED BUGS
80. CASSAVA CULTIVATION
81. CASSAVA MEALYBUGS
82. VARIEGATED GRASSHOPPER
83. GREEN SPIDER MITE
84. COTTON STAINER
85. COTTON
86. PESTS OF VEGETABLES
87. GRASSHOPPER






88. THRIPS
89. LEAF ROLLER

136. FEEDING MECHANISMS IN HOLOZOIC ORGANISMS
137. TYPES OF DIETS
138. FATTENING OR FINISHING DIETS
139. LAYER DIETS
140. BALANCED DIETS
141. LACTATION DIETS
142. MALNUTRITION
143. DISEASE, CAUSES, SYMPTOM CORRECTION
144. RANGE MANAGEMENT AND IMPROVEMENT
145. LIVESTOCK DISEASES
146. VIRAL DISEASES
147. RINDER PESTS
148. NEWCASTLE DISEASE
149. BACTERIA DISEASES
150. ANTHRAX
151. BRUCELLOSIS
152. TUBERCULOSIS
153. FUNGAL DISEASES


154. PROTOZOAN DISEASES
155. TRYPONOSOMIASIS
156. COCCIDIOSIS
157. RED WATER FEVER(PIROPLASMOSIS)
158. ENDO PARASITES
159. TAPE WORM
160. ROUND WORM OF PIGS
161. LIVER FLUKE
162. ECTO PARASITES
163. TICK
164. LICE

THE LARVA
In about four to seven days, the eggs hatch open and the larvae come out. The larva is a small, very active animal with a small head, big thorax and long segmented abdomen. It has a large number of brushes. At the tail end is a breathing tube. It lies on the surface of water.
THE PUPA
The larva changes into a comma-shaped pupa after about eight to eleven days. It has a big head with big eyes and breathing tubes.
THE ADULT
As previously described, it is a small insect which is active at night or in dark rooms. The female hums. It has a long piercing mouth and bushy feelers.

PREVENTION MALARIA
Since malaria is caused by parasites carried by mosquitoes, it is best prevented by killing and destroying all stages of mosquitoes.
1. All adult mosquitoes should be killed by spraying houses with shelltox, DDT, and other insecticides.
2. All standing water in cans and empty containers should be drained away. Exposed water should not be allowed to remain for more than four days. Plants such as the cocoyam, banana and plantain should not be cultivated near houses, since between the leaves of these plants water will accumulate, thus, providing a suitable breeding place for mosquitoes.
3. The surface of stagnant pools which cannot be drained should be sprayed with oil. The oil spread over the water surface, prevents the larvae and the pupae of breeding mosquitoes from breathing. They will suffocate and die.
4. Quite occasionally we have large ponds of water. To prevent the breeding of mosquitoes, it is advisable to introduce some fish into such ponds. The fish will feed on the larvae and pupae.
5. Attacks by mosquitoes can be prevented by sleeping under mosquito nets. Where possible house should be mosquito-proof with mosquito netting of fine wires or muslin netting.
6. Malaria can be avoided by taking few tablets of some medicines regularly. Such medicines include: nivaquine, camoquin, daraprim, etc. The medicines destroy the malarial parasites as they enter the body and thus prevent them from causing any damage to the blood.
2. SLEEPING SICKNESS
Sleeping sickness is very common in tropical Africa. In Nigeria, it is most common in the northern states. They attack cattle and horses.it also attacks man.
In man, sleeping sickness begins with a painful swelling in the skin. This is followed with fever, headache, pains and swelling of the neck. In later stages, the patient loses weight, becomes weak, dull, drowsy, and sleepy and may finally die.
CAUSES AND SPREAD
Sleeping sickness is caused by some parasitic germs called trypanosomes. This germs are spread by a fly known as tsetse fly. When the fly bites a patient the parasites are introduced into the skin. From the skin the parasites enter the blood from where they are sent to other parts of the body including the brain.
PREVENTION OF SLEEPING SICKNESS








1. In tsetse fly areas, all bushes near houses should be cleared.
2. Since tsetse flies breed in swamps by rivers and lakes, they can be eliminated or prevented from spreading if the bushes around these rivers and lakes are cleared for considerable distances.
3. It is advisable to wear clothes which cover most parts of the body.
4. Some chemicals such as DDT, dieldrin, etc. may be used to spray to kill tsetse flies.

3. YELLOW FEVER
Yellow fever is a disease caused by a germ (virus) carried by Aedes mosquitoes.
Yellow fever usually starts with fever and headache. This is accompanied with loss of appetite, some pains and general weakness
In severe cases, however, the patient becomes very ill due to the attack of patient’s liver and kidneys by the disease germs. The patient becomes yellow and it is important to note that a large number of patients with severe attacks usually die.

PREVENTION OF YELLOW FEVER
1. All mosquitoes must be destroyed by draining stagnant water in tins and cans.
2. Houses should be sprayed regularly to kill adult mosquitoes.
3. All bushes near houses should be cleared.
4. Always sleep under mosquito-nets.







Please share if you find our article good and useful
Important topics related to the above article
1. Recognizing living things
2. Biology as an enquiry in science
3. Branches of biology
4. Processes of methods of science
5. Usefulness of science
6. Living and non-living things
7. Characteristics of living things
8. Differences between plants and animals
9. Organization of life

what are the components of an ecosystem?


WHAT IS AUTOTROPHY AND HETEROTROPHY?

Autotrophy simply is the process whereby certain organisms, e.g. plants uses sunlight or chemicals to manufacture their food from inorganic substances through a process called photosynthesis
Heterotrophy refers to the process or situation where certain organisms such as animals cannot manufacture their own food but depends either indirectly or directly on the plants for their food.






Components of an ecosystem

The following are the factors and players found in an ecosystem

1.

AUTOTROPHS:

AUTOTROPHS are organisms such as plants and some bacteria which use the sunlight to manufacture their own food from inorganic substances. This is the process known as photosynthesis. Autotroph organisms are capable of synthesizing their own food, hence they are called producers in an ecosystem


THE PRODUCERS IN AN ECOSYSTEM

What are the producers in the ecosystem?
The producers in an ecosystem are the green plants or autotrophs which traps the radiant energy of sunlight and converts it to chemical energy. The producers forms the starting point of the food chain in an ecosystem. The producers or autotrophs provides food for other organisms living in the habitat.
Examples of producers in the habitat are the grasses, trees, phytoplankton, shrubs, water hyacinths and sea weeds

HETEROTROPHS

Heterotroph are mainly animals, which cannot manufacture their own food in or within the habitat. They depends solely on the producer such as plants for their food hence they are called consumers.
So animals that feeds directly on green plants –producers are called herbivores or primary consumers while the animals that feeds on the primary consumers are called the secondary consumers.
Animals that feeds on the secondary consumers are called tertiary consumers. Heterotrophs includes all animals, carnivorous plants, fungi, most protists and some bacteria

What are the consumers in an ecosystem?

A consumer is an organism which derives its nutrients, energy and food from eating plants directly or indirectly. In other words, consumers are organisms that depends on other organisms for food.
All consumers are heterotroph and they lack chlorophyll. They either animals that derive their nutrient, energy and food from feeding directly on plants such as cow, goat, sheep and elephant and so they popularly known a herbivores or primary consumers
The animals which also feed on the primary consumers, like dog, lions, leopard and tigers are called carnivores or secondary consumers.
Primarily, consumers are heterotrophs that feed on other organisms. They include all holozoic organisms such as herbivores, carnivores, omnivores, decomposers, and parasites. The examples of heterotrophs or consumers in a terrestrial ecosystem are caterpillars, cow, lions, toad, hawk, man, lizard, dogs etc. while the aquatic heterotrophs are or include water fleas, tadpoles, larvae of insect and fishes








The composers in an ecosystem

Decomposers are bacteria or fungi which lives saprophytically or feed on dead remains of plants, animals and other organisms, leading to or breaking down of organic matters to produce soluble nutrients which is absorbed by plants. Decomposers are organisms that feeds on dead organisms. They helps to break down dead organic matters and release simple chemical compound which plants can absorb and use again. Other examples of decomposers are insect such as termite and larvae of housefly.

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Important topics related to the above article

17. Form in which living cells exist
18. Structures of plants and animal cells and functions of their components
19. Similarity and differences between plant and animal cell
20. Diffusion
21. Osmosis

1. Modes of nutrition in animals
2. Saprophytic nutrition
3. Parasitic nutrition
4. Forages and farm animal nutrition
5. Water as a food substance

28. Osmosis
29. Diffusion
30. Turgidity
31. The cell and its environment
32. Mitosis and meiosis


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HERE YOU WILL FIND EVERY AVAILABLE TOPICS ABOUT AGRICULTURAL SCIENCE AND BIOLOGY. AND THE LINKS TO THEIR VARIOUS SOURCES.

1. DEVELOPMENT OF AGRICULTURE
2. IMPORTANCE OF AGRICULTURE
3. SUBSISTENCE AGRICULTURE
4. COMMERCIAL AGRICULTURE
5. PROBLEM OF AGRICULTURAL DEVELOPMENT
83. SOIL TEXTURE
84. IDENTIFICATION OF SOIL TYPES THROUGH EXPERIMENTS
85. RETENTION OF WATER BY VARIOUS SOIL
165.
AGRICULTURAL MECHANIZATION
166. THE CONCEPT OF MECHANIZATION

RESPIRATORY SYSTEM AND DISEASES



RESPIRATORY SYSTEM

1. Describe the different types of respiratory systems and diseases 
2. List the characteristics of a respiratory surface.
3. Draw and label some of the respiratory organs of some animals.
4. Explain the various mechanisms of respiration in some animals, e.g. mammals.
5. Describe the mechanism of exchange of gases through the stomata of plants.

DEFINITION OF RESPIRATION

Respiration is defined as a process in living organismscells involving enzyme catalysed chemical reactions in which food substances or glucose are broken down within cells, to release energy, in the presence or absence of oxygen. In other words, respiration is a biochemical activity of the cell in which glucose is broken down






by a series of reactions controlled by enzymes to release energy. In mammals, oxygen is breathed in and it breaks down the food substances (glucose) to release energy, carbon dioxide and water. Carbon dioxide and water are regarded as waste products of respiration. The energy so released is used by living organisms for various life processes.

Importance of energy to living organisms during respiration 

1. Energy is required for transportation of materials within the body and it is acquired through respiration 
2. It is needed by animals for movement.
3. It is required for the maintenance of body temperature with heat energy.
4. It is required for the synthesis of substance such as protoplasm and other body materials needed for growth and repair of the body.
5. Energy acquired during respiration is required for reproduction.
6. It is important in excretion in living organisms.
7. Energy is required in the transmission of nerve impulses and co-ordination.
8. It helps to produce sound e.g. speaking in human.
9. It helps to produce electrical shocks for offence or defence as in catfish.
10. Energy is required by all organisms during reproduction.

Types of respiration

There are two major types of respiration.


These are:
i. Aerobic respiration
ii. Anaerobic respiration

i. Aerobic respiration: aerobic respiration is the type of respiration which requires oxygen to break down glucose (substrates) into water, carbon dioxide and energy (ATP).
ii. Anaerobic respiration: anaerobic respiration is the type of respiration which does not require the presence of oxygen to provide energy. During anaerobic respiration, glucose is broken down to yield carbon dioxide, alcohol (ethanol) and energy.

phases or stages of respiration

Respiration takes place in two phases or stages. These are external and internal (tissue) respiration.
1. External respiration (breathing): external respiration or breathing is defined as the exchange of gases between the environment and the respiratory organs of living organisms. In other words, external respiration simply involves the breathing in of air or oxygen into the respiratory organs such as lungs or gills otherwise called inspiration or inhalation and the breathing out of carbon dioxide and water vapour into the atmosphere otherwise called expiration or exhalation.
2. Internal (tissue) respiration: internal or tissue respiration is defined as the oxidation of organic food substances within the cells leading to the release of energy, carbon dioxide and water. In other words, tissue respiration takes place when the oxygen taken in is used up by the individual cells in the body for the oxidation of food substances. Carbon dioxide, water and energy are given out by these cells in return. Internal, tissue or cellular respiration can be represented by the equation:
C6H12O6 + 6O2(R) 6H2O + Energy (Glucose) (Oxygen) (Water) (Carbon dioxide) ATP
In summary, the main purpose of respiration is to generate energy required by the body for various life processes.






CONDITIONS NECESSARY FOR RESPIRATION

For efficient respiration (gaseous exchange) to take place, the following condition must prevail or be available:
1. Respiratory medium: respiratory medium refers to the surroundings of the organism from which it obtains oxygen. Examples of respiratory media are air and water.
2. Respiratory organ: this is the organ such as lungs in mammals and gills in fish through which oxygen is taken in to the body and carbon dioxide and water vapour are given out. The taking in of one gas, e.g. oxygen and the given out of another, e.g. carbon dioxide and water vapour is called gaseous exchange.
3. Transport medium: this is a system which moves the dissolved gases, e.g. carbon dioxide which needs to be eliminated from the body. Example of transport medium in mammal is the blood.
4. Ventilation: the movement of water or air in one direction over the respiratory surface is called ventilation. This helps to renew the air or water in contact with or near a respiratory surface. Ventilation mechanism as in human breathing, increases the rate of gaseous exchange.
5. Respiratory surface: the respiratory surface refers to the definite surface of the body such as the surface of the lungs or a gill where gaseous exchange takes place.

characteristics of respiratory surfaces

Respiratory surfaces, be it in plant or animal must have the following characteristics:
i. Respiratory surfaces must be moist because gases diffuse in solution through them.
ii. It must be permeable to allow gases to pass in and out of them.
iii. It must be thin walled to shorten diffusion distance and make diffusion easier and faster.
iv. It must have adequate supply of transport medium, e.g. blood.
v. It must have a large surface area to aid easy diffusion of gases.
vi. Respiratory areas must be highly vascularised, i.e. equipped with capillaries or similar network to bring in or take away diffused gases.

TYPES OF RESPIRATORY SYSTEM

Respiratory system includes all the structures and organs of living organisms associated with the process of taking oxygen into the body and giving out carbon dioxide and water vapour into the environment.
Organisms adopt different types of respiratory systems depending on their types, complexity, size and the habitat in which they are found.

Different Organisms and their Respiratory Systems

Organisms
Respiratory system/organ
1. Unicellular organisms, Body surface
e.g. Amoeba and paramecium
2. hydra and tapeworm cell membrane
3.earthworm wet skin or body surface
4. fishes e.g. Tilapia gills
5. Arthropod, e.g. insects tracheal system
6. Arachnids, e.g. spiders lung books
7. Tadpoles gills
8. Reptiles, e.g. lizard lungs
9. Amphibians, e.g. mouth, skin and lungs
Toads and frogs
10 Aves, e.g. birds lungs
11 Mammals lungs
12 Flowering plants stomata and lenticels

MECHANISM OF RESPIRATORY SYSTEM IN LOWER ANIMALS

UNICELLULAR ORGANISMS






There are no special respiratory organs in unicellular and aquatic organisms such as Amoeba and Paramecium. Oxygen that dissolves in water diffuses into the body while carbon dioxide goes out of the body through the entire body surface. The cell membrane acts as the respiratory surface. The concentration of oxygen in water is higher than that inside the body, hence it will diffuse (diffusion and osmosis) into all parts of the body. On the other hand, carbon dioxide inside the body is higher than that of the water, hence it will diffuse out of the body. The process of gaseous exchange in unicellular organisms is made possible by simple diffusion. These organisms have large surface area to volume ratio hence diffusion through the body surface alone is enough to satisfy its gaseous exchange needs.
INSECTS
Insects generally use the tracheal system for gaseous exchange. The insects have tiny openings in their abdomen called spiracles through which oxygen diffuses into the body and carbon dioxide diffuses out. The spiracles lead into certain tubes called tracheae (singular trachea). These tracheae further divide into smaller tubes called tracheoles and these tiny tubes get into the tissues and cells through the body fluid.
Insects such as cockroach, grasshopper etc. Use the tracheal system.
The insects perform breathing movements by compressing its body dorso ventrally (i.e. inwards from both sides along its entire body) and then relaxes it. When it compresses its body, it becomes flattened and air is expelled from the tracheae through the spiracles. When it relaxes its body air enters into the tracheae.
During the process of compression and relaxation of the body, oxygen in the air taken in dissolves in the body fluid at the end of the tracheoles from where it enters the various cells. Carbon dioxide from the cells diffuses into the body fluid then into the tracheae and finally comes out of the insect body through the spiracles.
RESPIRATORY DISEASES

Respiratory disease is a medical term that encompasses pathological conditions affecting the organs and tissues that make gas exchange possible in higher organisms, and includes conditions of the upper respiratory tract, trachea, bronchi, bronchioles, alveoli, pleura and pleural cavity, and the nerves and muscles of breathing. Respiratory diseases range from mild and self- limiting, such as the common cold, to life-threatening entities like bacterial pneumonia, pulmonary embolism, and lung cancer.
HERE YOU WILL FIND EVERY AVAILABLE TOPIC ABOUT AGRICULTURAL SCIENCE AND BIOLOGY AND LINK TO THEIR VARIOUS SOURCES.
1. DEVELOPMENT OF AGRICULTURE
2. IMPORTANCE OF AGRICULTURE
3. SUBSISTENCE AGRICULTURE
4. COMMERCIAL AGRICULTURE
5. PROBLEM OF AGRICULTURAL DEVELOPMENT
6. SOLUTIONS TO POOR AGRICULTURAL DEVELOPMENT
7. AGRICULTURAL LAWS AND REFORMS
8. ROLES OF GOVERNMENT IN AGRICULTURAL DEVELOPMENT
9. AGRICULTURAL POLICIES
10. PROGRAM PLANNING IN AGRICULTURE
34. FORESTRY
35. WILDLIFE CONSERVATION
36. FACTORS AFFECTING LAND AVAILABILITY
37. TOPOGRAPHY
38. SOIL
39. BIOLOGICAL FACTORS
40. SOCIAL-ECONOMIC FACTORS
41. ENVIRONMENTAL FACTORS AFFECTING AGRICULTURAL PRODUCTION
42. CLIMATIC FACTORS AFFECTING AGRICULTURAL PRODUCTION
43. TEMPERATURE
44. RAINFALL
45. WIND
46. SUNLIGHT
47. SOLAR

48. BIOTIC FACTOR AND AGRICULTURAL PRODUCTION
49. PESTS
50. BIRDS
51. DISEASES
52. SOIL MICRO-ORGANISMS
53. SOIL PH
54. ROCK FORMATION
55. IGNEOUS ROCK
56. SEDIMENTARY ROCKS
57. METAMORPHIC

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