Agriculture food supply and population in our environment

RELEVANCE OF BIOLOGY TO AGRICULTURE
Biology is the stdy of living things Agricuitun the growing of plants and the rearing farm animals to provide our needs the cultural activities a basic knowledge of biology is necessary. Such knowledge includes

. the structure, function and nutrition of plants and animals

* diseases which affect plants and animals and the organisms which cause them ;

* ecological systems
*soil ; and
* genetics.


Classification Of Plants

Plant can be classified in several ways. In Botany (the study of plants), all plants are grouped into the plant kingdom and subdivided as on pages 15 to 20. This classification, which is based mainly on structure, function and evolu- fo
tionary trends, is not particularly useful to a farmer. However,more useful and appropriate ways of classifying plants include grouping them

. into annuals, biennials and perennials; and
. for agricultural purposes.

Annuals, Biennials and Perennials Plants are commonly grouped into annuals, biennials and perennials according to the span of their life cycles.

This classification applies mainly to flowering plants, the group to which most crop plants belong.

It is a practical way of classifying crop plants as it helps a farmer to
plan how to use his land to meet his goals.

Annuals These plants complete their entire life cycles and die within one growing season which may be from a few months to a year.

Many im-portant agricultural plants are annuals. Examples include rice, wheat, maize, bean, flax, jute and sunflower


Biennials These plants grow and store food during the first growing season, and use it in the second growing season to produce flowers, fruits and seeds before they die example include cabbage, radish and turnip which are harvested for food immediately after the first growing season.

Perennials These include trees, shrubs and herbs which continue to grow from year to year producing flowers, fruits and seeds for many years. Agriculturally important perennials include herbaceous ones such as ginger and onion, and woody ones like rubber, oil palm, cacao, mango and coconut.

Agricultural Classifications
In agriculture, cultivated plants or crops are usually grouped according to the products for which they are grown as given below

Cereals These plants belong to the grass fam
ily. They include maize, rice millet, Guinea corn and wheat. They are grown for their
grains which form the bulk of the world's food supply. The grains have a high starch content and contain varying amounts of proteins, oils and vitamins.

The legumes are an important source of dietary protein. They also supply
protein-rich fodder for livestock in tropical countries. In addition, legumes replenish soil nitrogen because nodules on their roots contain nitrogen-fixing bacteria. This makes them important in crop rotation. Legumes include bean, groundnut, cowpea, soya bean, oil bean,Legumes lima bean and yam bean.

Root crops They are grown mainly for starch and form the staple food of the people in many tropical countries. They include cassava, yam and sweet potato.

Vegetables Various kinds of vegetables are grown to supply dietary vitamins and certain minerals like calcium. Examples include to-mato, okra, onion, pepper and spinach.

Fruits Many plants are grown for their fruits which are rich sources of vitamins, especially vitamins A and C, minerals and sugars. Most fruits are eaten raw. Examples include orange pineapple, banana, plantain, mango, pawpaw and native pear.

Beverages and drugs The crops which yield ese products include cacao, coffee, tobacco and quinine. The products, cocoa and coffee,

are food drinks; tobacco is a stifnulant; and quinine is used as a medicine.

Spices Pepper, ginger, cinnamon and cloves belong to this group. They are used mainly for flavouring food.

Oils The fruits and seeds of certain plants are rich in oil. Such oil crops include oil palm, Shea butter, coconut and sunflower.

Forage crops These are the grasses and leg-umes that are grown for animal feed.

Latex When a cut is made on the trunks of certain trees, a. milky fluid called latex flows out. The rubber tree is grown in tropical coun-tries for its latex which is used to make natural rubber.

Fibres Plants such as jute, hemp and cotton are grown for their fibres which are used for making ropes and cloth.

Soil
Soil is very important in agriculture. It provides anchorage for plants. It also supplies water and mineral salts that are essential for their nutrition. Animals, including humans, depend on plants for food, and as such, indirectly depend on the soil.

Soil characteristics
Most sails are made up of a misture of sand silt and chay with varying amounts of humus

A sandy aoti has very little humus Since the particles in a sandy soll are large, it has a
oarse lesture wüh plenty of space between the particles Hence, it is well aerated but water dvains through it quiekly leaving it dry. It is not a good suil tor erop culivation

A clayey soil is made up of very fine parti-cles with very little space in between them. Asa result, it becomes easily water logged during the wet season and is poorly aerated, During the dry season, it hardens and cracks. It is also not a good soid for erop cultivation

Loamy soil contains a misture of sand and clay particles with plenty of humus. It has a good crumb structure which allows water to drain through it while holdi!男back just enough for plant growth It is well aerated and rich in plant nutrients. This is the best type of soil for crop cultivation

Soil Erosion
Brosion is the wearing away and removal of fertile topsoil from an area by the wind and water (during a heavy rainfal).

Plants cannot
grow on eroded land. Erosion is, therefore, a serious problem as it affects the economy of a country that depends on agriculture for sup-plying its needs Erosion is often due to bad farming prac-tices such as overgrazing of pastures, continual cropping without fallowing or adding fertiliz-ers, and exposing soil surfaces for long periods Farmers can prevent erosion by good farming practices.

This includes the following:
Growing fast-growing cover crops in be-tween slow-growing crop plants such as oil
palms. Cut grass and crop residue can be spread over bare ground to protect it. This
is known as mulching.
Contour ploughing or ploughing along the contour of the land to reduce water runoff.

Gaseous Exchange of Respiration and Respiratory Systems

Every time we breathe we take in life-supporting oxygen from the surrounding air. Oxygen is extremely important for life : we can survive for weeks without food and for days without water but only a few minutes without oxygen.

In our bodies oxygen is used to release energy stored in the chemical fuel we consume as food. This energy is vital for powering our life process. Broadly, the sequence of processes leading to the release of energy in living cell is called respiration. In most multicellular animals, it involves

*the intake and absorption of oxygen from the surrounding environment ;
*the transport of oxygen to the individual cell in the body and
*using oxygen to release energy as (ATP) from energy - rich substance via the kreb's cycle.

The above metabolic process which uses oxygen to release energy at ATP in living cell is known as cellular respiration, and has been discussed in chapter 11 in this chapter, we shall discuss the respiratory system that are concerned with the intake of oxygen and it entry into the circulatory system for distribution to the individual cell in the bodies of various organisms.

The same system also get rid of carbon dioxide and water, the waste products of cellular respiration in fact, the intake and absorption of oxygen Is automatically accompanied by the elimination of carbon dioxide and water in the surrounding. Thus, these respiratory system are also known as Gaseous exchange systems.

TYPES OF ANIMAL RESPIRATORY SYSTEMS
well - developed respiratory system are found in higher animals. Simple organisms, like monerans, protists, fungi and some multicellular animals and plant, do not have any particular respiratory system. The games simple diffuse through their cell or body surfaces.
The following are important Gaseous exchange or respiratory structures found in protists and animals : body surface, gills, trachea and lungs.

DIFFUSION AND RESPIRATORY STRUCTURE.
gases enter and leave the cell of an organism by diffusion. The gases, however must first be dissolved in water before they can diffuse across cell membrane. Hence respiratory structure must have Gaseous exchange surface that are bathed in water or Moist.

Respiratory structure must also have ways of increasing the rate of Gaseous diffusion to do this

*the Gaseous exchange surface must be large
*the barrier (I.e the membrane) across which the gases diffuse must be thin;
*there must be ventilation mechanisms to maintain a big difference in the concentration of the gas across the barrier (I.e maintain a steep diffusion gradient) and
* the Gaseous exchange surface must be closely linked to the transport system.

Note by removing and distributing the diffusing gas, the transport system would also help to maintain a steep diffusion gradient across the Gaseous exchange surface.

BODY SURFACE
unicellular organisms like amoeba, Gaseous exchange take place through the plasma membrane the size of such an organism is small to ensure the sufficient oxygen reaches all parts of the organisms to maintain its life processes. In amoeba, all parts of it protoplasm are within a distance of 0.5mm from the plasma membrane. Thus there is no necessity for a special respiratory structure.

MULTICELLULAR ANIMALS
multicellular animals can have larger body surface for Gaseous exchange than unicellular organisms. However, these organisms too cannot grow beyond a certain size since the body surface area does not increase as rapidly as body size or volume thus only few simple multicellular animals carry out Gaseous exchange thorough their body surface or skin without using specialized respiratory structures. Such animals are fairly inactive so that their energy requirement and as a result, their oxygen demands are low

GASEOUS EXCHANGE BODY SURFACE IN SOME SIMPLE ANIMALS
Sponge and coelenterates in these simple animals all their body cells are in direct contact with the surrounding aquatic medium Thus cell can get it own supply of oxygen

FLATWORM
in flatworm the body is extremely flattened and elongated in the free living planaria the body is 10mm long and only 0.6mm thick this is the body form

* increases the surface area to volume ratio and
*brings the innermost cells very close to the body surface.

It is therefore, possible for these worms to meet their oxygen requirements through diffusion over their body surface. In addition free living flatworms are found in well aerated flowing waters so that oxygen concentration in the water surrounding them is high.

Note parasitic flatworms are anaerobes as the oxygen concentration in their environment is very low.

ANNELIDS
In this more advanced worms, Gaseous exchange occur by diffusion over their body surface this is possible because

*their cylindrical shape give a high surface area to volume ratio so that the rate at which oxygen diffuse is sufficient to meet the worms requirements and

* the cell in their body surface (epidermis)  have rich supply of blood capillaries.

AMPHIBIANS
these more advanced group of animals live on land and water. They have lungs which are not properly developed to meet their oxygen demands. As a result many amphibians, like frog, obtain much of their oxygen through their Moist skin. This is known as cutaneous respiration. It is possible for the skin of a frog to carry out Gaseous exchange because the skin is

* richly supplied with blood capillaries and
*kept Moist by mucus secreted by glands.

AQUATIC RESPIRATORY STRUCTURE:

THE GILL Gill are specially respiratory organ used for absorbing dissolved oxygen from an aquatic medium. Basically they are outgrowth from the body which projects into the external environment.
They are very closely linked with circulatory system gills range from very simple form found in certain sea slugs to very complex ones, enclosed in chambers, found in bony fishes

SIMPLE GILLS
external gills are very simple respiratory structures just outgrowth of skin which projects into the water they are however
*highly branced and convoluted exposing a large Gaseous exchange surface to water and
*richly supplied with blood capillaries

External gills are found in certain sea Slugs and many fish and amphibians larvae water only circulate over the gills when these organisms move. Movement on the other hand is hampered by the highly branched gills

Definition of Microorganisms on earth and man as a cell

A Microorganisms also spelled micro-organism, micro organism or Microorganisms or microbe is a microscopic organisms that comprise either a single cell (unicellular)  cell cluster, or multicellular relatively complex organisms. They are indeed, organisms or forms of life requiring magnification with the aid of a microscopic to see and resolve their structures.

 Microorganisms are very diverse ;they include bacteria, fungi, algea, and protozoa ;microscopic plant (green algea) ; and animal such as rotifers and planarians. Some microbiologist also include viruses, but others consider these as nonliving. Most Microorganisms are unicellular (single-celled), but this is not universal, since some multicellular organisms are microscopic, while some unicellular proist and bacteria, like thiomargarita Namibiensis, are microscopic and visible to the naked eye.

Indeed, the word "microscoorganisms"  is general terms that becomes more understandable if it is divided into its principal types as previously mentioned which are predominantly unicellular microbes.  Viruses are also include, although they cannot live or reproduce on their own. They are particles, not cells, they consist of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), but no both. Viruses invade living cells- bacteria, algea, fungi, protozoa, plants, and animals(including humans) and use their host metabolic and genetic machinery to produce thousands of new virus particle. Some virus can transform normal cell to cancer cells. Rickettsias and chlamydiae are very small cell that can grow and multiply only inside other living cells.

 Although bacteria, actiomycetes, yeasts, and molds are cell that must be magnified in order to see them, when cultured on solid media that allow their growth and multiplication, they form visible colonies consisting of millions of cells.

The study of Microorganisms is called microbiology, a subject that began with Anton Van leeuwenhoeks's discovery of Microorganisms in 1675, using a microscopic of his own design. Microorganisms live in all parts of the biosphere where there is liquid water, including soil, hot springs, on ocean floor, high in the atmosphere and deep inside rock within the earth's crust.

Microorganisms are critical to nutrient recycling in ecosystem as they act as decomposers. As some Microorganisms can fix nitrogen, they are vital part of the nitrogen cycle and recent studies indicate that airborne microbes may play a role in precipitation and weather.

Microbes are also exploited by scientists in biotechnology, both in traditional food and beverage preparation, and in modern technologies based on genetic engineering however, pathogenic microbes are harmful, since they invade and grow within other organisims causing diseases that kills human, other animal and plant.

MICROBIAL EVOLUTION
single-celled Microorganisms were the first form of life to develop on earth, approximately 3-4 billion years ago so, for most of the history of life on earth the only form of life were Microorganisms. Fossil microbes have also been found in rocks 3.3 to 3.5billion years old since then, microorganisms have had the principal task of recycling organic matter In the environment. As such they are absolutely essential to the health of the earth. Without them, the earth would be a gigantic, permanent waste dump.

Microorganisms are responsible for recycling the huge masses or organic matter synthesized by plant as life on earth evolved. Furthermore, micro organism -  the cynabacteria or their DNA in the chloroplast of the plant cells - were the source of most of free oxygen in the early atmosphere. They also oxidize ammonia (the universal end product of protein metabolism)  to nitrate, which is the only nitrogen source used by plant and is therefore essential for production of our plant foods.

Microorganisms are also responsible for cellouse hydrolysis in the runmens (first stomach compartments)  of cattle, facilitating the production of animal protein for human consumption. And, in recent times, Microorganisms have been the source of antibiotics that have enabled the cure of numerous diseases.

Blue-green algea (cyanobacteria) are prokaryotes (that is their cell have no distinct nucleus). They are very independent nutritionally since they can carry out photosynthesis using chlorophyll. Thus they can synthesize sugars for energy from carbon dioxide using solar radiation. They also release oxygen. They can respire aerobically and can fix nitrogen, generating amino acid and protein. They require only water, nitrogen gas oxygen carbon dioxide, some minerals and sunlight. The evidence is that they were on earth 3.2billion years ago. The cyanobacteria are among the earliest Microorganisms and very important even today.

Green algea are eukaryotes (that is, their cells have a distinct nucleus). They evolved about one billion years ago. They contain chlorophylls a and b, which enables them to convert carbon dioxide, through radiation, to sugar and to polymerize sugar to starches, hemicelluloses, and cellulose some of our most important source of food energy.

Green algea are still major source of food in the oceans green algea were likely the life forms that evolved into plants which first lived primarily in the oceans but moved to the land about 450 million years ago about the same time as the amphibians and the first land animal evolved. It is believed that the first mammals evolved about 150 millions years later, along with insects and reptiles, which were dominant. Another 150million years later, dinosaurs and first birds evolved, along with the first flowering plants. During the entire period from, 3.6 billion years ago, microorganisms were consuming and recycling the organic matter from themselves and other forms of life as they lived and died.

For several billion years, bacteria, algea, and other Microorganisms serves food for other microbes and for higher animals as they evolved. When plant evolved in the oceans and then subsequently moved to land ; they become major sources of food for other forms of life, including Microorganisms, animals and eventually humans.

Most Microorganisms reproduce rapidly, but slow when the environment is cold and microbes such as bacteria can also freely exchange genes by conjuction, transformation and transduction between widely-divergent species. This horizontal gene transfer, coupled with a high mutation rate and many other means of gene variation, allows Microorganisms to swiftly evolve (Via natural selection) to survive on new environment and respond to environmental stresses. An example of this is the evolution of specialized nylon-eating bacteria, it's also been studied in experimental evolution. This rapid evolution is important in medicine, as it has led to the recent development of super-bugs—pathogenic bacteria that at resistant to morden antibiotics.

Reproduction in Organisms, introduction, Mode Of Reproduction In them

Reproduction is the formation of new individual since life or organisms is limited in duration it has developed certain mechanism by which it can reproduce themselves in order to continue the permutation of the the spice and also to multiply in number Reproduction is one of the ubiquitous miracle of life. Evolution is linked to Reproduction, because the ceaseless replacement of ageing predecessor with new life gives animal the means to respond and evolve in changing environment as the earth itself has changed over the ages. It is also any process by which a parental cell or organism produce offspring among eukaryots, asexual Modes include, binary fission, budding, prokaryotic fission. Viruses do not reproduce themselves, host organisms execute their replication cycle.

MODE OF REPRODUCTION
the following are the principal method of Reproduction Asexual Reproduction, sexual Reproduction and vegetative propagation. There are also special modes of Reproduction, in plant Aproxixis, Apospory And polyembroyony.

1) Asexual Reproduction : is the Reproduction of individuals without gametes, that is eggs or sperm. It includes anumber of distinct process without involving sex or a second parent. The offspring produced by Asexual Reproduction of an individual all have the same genotype and are called clones.

Asexual Reproduction appears in bacteria, protists, in many invertebrates phyla such as cindarians bryozoans, annelides, echinoderms and hemichordates. In animal phyla in which Asexual Reproduction occurs most members employ sexual Reproduction as well. In these group, Asexual Reproduction ensure rapid increase in numbers when differentiation of the organisms has not advanced to the point of forming gametes. ASEXUAL Reproduction take place by means of Asexual Reproduction units, called sporses, produced by the mother plant and by fission (by the division of the mother cell in the case of unicellular plants).

BASIC FORM OF ASEXUAL REPRODUCTION : fission (binary and multiple fission)  budding, gemulation and fragmentation.

BINARY FISSION, is common among bacteria and protozoa. In binary fission the body of the parent divides by mitotic cell division into two approximately equal parts each of which grows into and individual similar to the parent. It may be lengthwise as in flagellate protozoa, or transverse, as in ciliate protozoa. In multiple fission, the nucleus divides repeatedly before division of the cytoplasm, giving rise to many daughter cells simultaneously. Example of binary fission occurs in Euglena

SPORE FORMATION
in Asexual production is called sporogony is a form of multiple fission that is common among some parasitic protozoa, example is a malarial parasite. Ciliate motile spores are called zoospores produced by many algae and fungi.

BUDDING
this is an unequal division of the organisms where the new individual arises as an outgrowth (bud)  from the parent, developes organ like those of the parent, and leads to the formation of a colony. Budding occurs in several animal phyla and is especially prominent in cindarians.

Gemulation
Is the formation of new individual from an aggregation of cell surrounded by a resistance capsule, called a gemmule. In many fresh water spomgesgemmule develop in the fall and survive the winter in the dried or frozen body of the parent. In the spring, the enclosed cell becomes active, emerges from the capsule and grows into new sponge.

FRAGMENTATION
a multicellular animal breaks into two of more parts with each fragments capable of becoming a complete individual. Many invertebrate can reproduce assexually by simply breaking into two and regenerating the missing part of the fragments.

SEXUAL REPRODUCTION
sexual reproduction is the production of offspring framed by Union of gametes from two genetically different parents.
 The offspring will thus have a new genotype different from either parent.
 The individuals sharing parenthood are characteristically of different sexes, male and female (there are expectation among sexually reproducing organisms such as bacteria and some protozoa in which sexes are lacking) the distinction between male and female is based not on any difference in parental sizes or appearance, but on the size and mobility of the gamets (sex cells) they produce the ovum (egg) is produced by the female ova are large because of stored yolk to sustain early development, the ova is also motile and produced in relatively small numbers.

SPERMATOZOON (sperm)  is produced by male sperm are small, motile, and produced in enormous numbers, each is a striples-down package of highly condensed genetic materials designed for the single mission of finding and fertilizing the Egg.

MEIOSIS
is another crucial event that distinguishes Sexual from Asexual reproduction. Meiosis is distinctive type of gamete-producing nuclear division. Meiosis differs from ordinary cell division (mitosis) is being double division. The chromosomes split once, but the cell divides twice, produce four cells, each with half the original number of chromosomes (the haploid numbers). Meiosis is followed by fertilization in which two haploid gamets are combined to restore the normal (diploid) chromosomal number of the species. The new cell (zygote, which now begins to divide by mitosis) has equal numbers of chromosomes from each parent and accordingly is different from each. It is a unique individual bearing a recombination is the great strength of Sexual reproduction that keeps feeding new genotypes into the population.

Many protozoans reproduce both sexually and assexually when Sexual reproduction does occur, it may or may not involve male or female gametes. Sometimes two mature Sexual parents merely join together to exchange nuclear material or cytoplasm (conjugation)  sexes cannot be distinguished in these cases. The male-female distinction is more clearly evident in the metazoans. Organs that produce germ cells are know as gonads. The gonads that produce sperm is called testis and that which forms the eggs, the ovary the gonads represent the primary sex organ the only sex organ found in certain group of animals. Most metazoans however, have various accessory sex organ (such as penis, vagina, oviducts and uterus) transfer and receive sex cells. In the primary sex organ the sex cell undergo many complicated changes during their development

BIAPARENTAL REPRODUCTION 
biaparental (bisexual)  reproduction is the common method of Sexual reproduction with which we are familiar. Involving Separate and distinct male and female individual. Each has its own reproductive system and produces only one kind of sex cell, SPERMATOZOON or ovum but never both. Nearly all vertebrates and many invertebrate have separate sexes and such conditions is called dioecious.

Introduction To Animal Science And The importance In Research

Taxonomy the branch of biology that names and classifies species has regrouped living things based on comparisms of DNA sequence from different styles species into three domains.

These are bacteria Archea and eukarya.
Domain bacteria and Archea are all prokaryotic single celled microscopic organisms.

DOMAIN EUKARYA — are organisms with eukaryotic cells. There are several Kingdom in this domain these include :

KINGDOM PROSTISTA — sometimes recorded as multiple Kingdoms. They are unicellular eukaryotes such as protozones (eg amoeba sp)

KINGDOM FUNGI — these are defined by their nutritional mode eg. Mushrooms which absorb nutrients from their surroundings. Some decompose dead organisms and organic wastes.

KINGDOM PLANTAE — these are multicellular eukaryotes that carry out photosynthesis eg grasses.

Kingdom Animalia— these are multicellular eukaryotes that ingest other organisms, that is they eat and digest other organisms eg man.

Animals belong to the kingdom Animalia and therefore are living things that are not planet generally capable of voluntary motion, sensation, etc.

Science is described as a branch of knowledge or study dealing with a body of fact or truth systematically arranged and showing the operating of general laws.

WHAT IS ANIMAL SCIENCE 
animal science is described as "studying the biology of animal that are under the control of mankind" it constitute a branch of agriculture that provide basic information in the science and art of raising certain species of domesticated and non-domesticated animals for human food. Animals science is the application of experimental investigation, cutting edge technology and other scientific principles for the advancement of efficient and environmentally friendly animal agriculture and improved food quality and safety.

Animal production is one of the major sector in Nigeria agriculture and contributes substantially to the economy of the country. Animal science covers most aspects of animal production and animal products. This include all husbandry facets and livestock species (cattle, sheep, goats, pigs, poultry, ostriches and horses) and the products derived from them (meat, milk and diary products, wool, mohair, eggs, skin and leather and feathers) as well as relevant aspects of aquatic (fish, etc)  and wildlife species. Animal science deals mainly with the three basic disciplines, namely breeding, physiology and nutrition, but also aspects of animal product science
 e.g meat, diary, wool, etc.

THE ANIMAL SCIENTIST 
animal scientist have careers in management and production vreterinary medicine, food processing and marketing, animal biotechnology, zoo and wildlife management, the pharmaceutical and feed industries, teaching, extension education and research. Those positions require skills in disciplines such as nutrition, genetics require skills in disciplines such as nutrition, genetics, physiology, environmental and waste management, meat and science and grOwth biology,. Animal health feeds and forage/browse utilization, engineering, business management /marketing and salesmanship.

Other skills of critical importance are computer proficiency, writing and oral cominication, problem solving and ability to build effective interpersonal relationship because of diversity among field of specialization. Students in the animal sciences also take courses in natural resources and environmental management, bioengineering, anatomy and reproductive biology, biochemistry and biophysics, chemistry, environmental biochemistry, food science and human nutrition, genetics, tropical plant and soil science, information and computer sciences, microbiology, oceanography, physiology, and zoology.

If you want to work with animal and benefit your community, then you may want to consider a rewarding career in one of the Many disciplines offered in the animal sciences the challenge to meet the future Projections of energy shortages, population growth, urbanization, and environmental conversation necessitates a continuing and increased need for highly trained professionals in animal sciences.
Training in animal science is Highly recommended if you are considering working in agriculture as a researcher, extension personal, a producer, a teacher or if you are interested in any of the many career options in agribusiness. Students also receive training in both basic and agricultural sciences. A major in animal science offers a path to a highly rewarding and challenging vocations. Animal science will ensure a stimulation and challenging career for a person whose interest lies in science, focused on dynamics of livestock production.

THE IMPORTANCE OF ANIMAL IN RESEARCH 
research involving laboratory animals is necessary to ensure an enhanced human and animal health and the production of the environment. In the absence of human data. Research of detecting important toxic properties of chemical substance and for estimating risk of human and environmental health.

Research animal must be used in a responsible manner. Scientifically - valid research designed to reduce refine or replace the need for laboratory animals is encouraged.
Research involving laboratory animal is important to people and to our quality of life. In the past century. Most inhabitants of this planet have experienced an unprecedented rise in living standard, life expectancy and personal opportunity in large part due to many ways of chemical have been put work for us. For example, drugs whose effect range from curing previously fatal bacterial infections, reducing the impact of AIDS, minimizing heart disease, decreasing aged related wrinkles, to reducing hair loss really widely available today. The many benefits of the diverse uses of our natural resources are an outcome of careful scientific research and of using chemicals in an appropriate and safe manner. Toxicologist, the scientists who help determine the limit for safe use of material, use modern technological research methods including test on animal to protect human and animal health and the environment.

CAREERS IN ANIMAL SCIENCE ANIMAL CARE AND WELFARE 

you will receive training pertaining to the current issues of animal welfare as they relate to production and husbandry. Employment opportunities exist with human societies animal shelter, and Allied veterinary groups animal. Animal health -  you will learn about diseases problems of livestock, poultry and compassion animals and their economic significance, causes public health Implications and control. Employment opportunities exist in areas such as veterinary medicine, veterinary technology and in various pharmaceutical industries.

ANIMAL PRODUCTION AND MANAGEMENT
You will learn the principles, theories and practices involved in the production of beef and diary cattle, swine, poultry, sheep, goats,horses, and aquatic animals.

Business - you will receive a background in economics and agricultural practices that are useful for agricultural loans commodity trading and agricultural businesses

Microbiology and micro organisms using of physical method in controlling it

1) Heat: heat treatment is a simple, inexpensive and lethal. It is the best method if the material being treated is not damaged by heat. Heat penetrates to kill micro organisms throughout the object.

A) Dry heat : it Sterlizes by denaturing protein in the laboratory, used to Sterlizes liquids and material easily charred. Used in food canning.

B) Moist heat : it Sterlizes by denaturing protein in the laboratory, used to sterilize liquids and materials easily charred. Used in food canning

C) Pasteurization : kills certain microorganisms by denaturing the protein. Eliminates pathogens and slows spoilage of milk and certain dairy products, wine, beer (canned evaporated or condensed milk is sterilized).

2) LOW temperature (cold) : Refrigerating and freezing can be used to control microbial growth and reproduction. It slows down chemical reaction. It preserves perishable Materials, including food and microorganisms.

3) Filtration : microorganisms can be efficiently removed by Filtration with either depth filter or membrane filter. This method physically removes cellular microorganisms. Air also can be sterilized by Filtration in the laboratory used to preserve certain beverages.

4) Radiation : some form of electromagnetic radiation kill living things, including microorganisms. The types of radiation that kill bacteria directly are all of shorter wavelength than visible light they are ultraviolet (UV)  light (Radiation with wavelength of 10 to 400nm) and ionization radiation (with a wavelength extending to about 0.01nm).

UV light sterilizes by damaging DNA in the laboratory used to sterilize surfaces

Two forms of ionizing radiation are x-rays and gamma rays. They sterilize by stripping electrons from atoms. Used to sterilize plastic equipment and surface of fresh fruits and vegetables.

Drying : drying (removal of water)  can be accomplished through evaporation is almost never used in the laboratory because it causes chemical changes, but it is widely used in the food industry. Lyophilization, or conversation from solid to gaseous state). This method stops microbial growth and stops most chemical reactions.

In the laboratory used to preserve cultures, proteins, blood.

CHEMICAL CONTROL ON MICROORGANISMS

physical agent are generally used to sterilize objects. Chemical on the other hand, are more often employed in disinfection and antisepsis. The proper use of chemicals agents is essential to laboratory and hospital safety. Chemical also are employed to prevent microbial growth in food and certain chemical are used to treat infectious diseases.

1) PHENOLS : kills most microorganisms by denaturing the proteins. It is used as a germicide.

2) PHENOLIC: kill most microorganisms by denaturing proteins and disrupt plasma membrane. It is used as disinfectants and antiseptics.

3) ALCOHOLS: are the most widely used disinfectants and antiseptics. They are bacterialdal and fungicadal but not sypoticidal, some liquid-containing viruses are also destroyed. The two most popular alcohol germicide are ethanol and isopropanol. Denatures protein and disrupts plasma membrane disinfects surface including skin and thermometers.

4) HALOGENS : kills microorganisms. Oxidizes vital biochemicals. It is used to disinfects surface including skin and water.

5) Hydrogen Peroxide : kills many microorganisms by oxidizing vital biochemicals. It is a mild skin disinfectant.

6) SURFACTANTS (soap and detergent) wash away microorganisms by physically removing them disinfects surface, including, skin bench tops.

7) HEAVY METALS (such as mercury, silver, arsenic, zinc and copper)  kills microorganisms. Heavy metals combine with protein to inactivate the microorganisms used as skin disinfectants.

8) Quanternary Ammonium Compounds (SALT) are used detergent that have antimicrobial activities are effective disinfectants. They disrupt membrane and are widely used as sterilizing agents.

9) ALDEHYDES: both of commonly used aldehydes formaldehydes and glutaraldehydes are high reactive molecules that combine with nucleic acids and protein and inactivate them. They are sporicidal and can be used as chemical sterilants. They are used to preserve tissues, prepare vaccines and sterilize surgical instruments.

10) ETHYLENE OXIDE : many heat-sensitivs items such as machine components structure and cathers are Sterlized with Ethylene oxide Gass it is both microbicidal and sporicidal and kills by combining with cell protein.

Chemotherapeutic Agent : the chemicals discussed so far are appropriate for use either on inanimate object or external host tissues. Chemotherapeutic agents are chemicals that can be used internally because they have selective toxicity that is they target the microbes and do relative little if any harm to the host. Most Chemotherapeutic agents are affective in controlling the growth of bacteria. There are many synthetic antibiotics for treating diseases caused by fungal, protists and viruses.

HOW MICROORGANISMS ARE STUDIED

the most important tool in studying microorganisms is the microscope. Microscope began in the century with Anthony Van Leeuwenhock and his little hand-held Microscope. He is regarded as the "FATHER OF MICROBIOLOGY". microscope crest a visible, detailed images of object that are different types of microscope but all of them depend on three factors I.E. magnification, contract and resolution to produce a clear image.

MAGNIFICATION : the primary function of a microscope is magnification, that is enlargement of image, this is done by using a convex lens (thicker in the center Than the edge). By refraction, it bends paravel rays of light from an object so that they meet at a single point, the focal point An enlarged image of the objects from behind focal point.

CONTRAST : this refers to a different in light intensity. It allows on to distinguish on part of an image from its surrounding. The image we see in a microscope is created by the light that is transmitted through the specimen (an object viewed under microscope).

RESOLUTION : Good resolution means you can distinguish two points in an image that are very close to one another. If resolution is poor, the two point merge and look like one another.

Microbiologist use many types of micro scopes to do their work they included both compound light Microscope and electron Microscopes.

LIGHT MICROSCOPE
a light microscope use a visible light as a source of illumination. A compound light microscope has two lens system and object lens and ocular lens. Another series of lenses called the condenser directs light through the specimen. The objective lens forms an image of the specimen in the tube of the microscope. The ocular lens magnifies and projects the image to the eye. Compound light microscope typically are provided with several objectives lenses : low power (10X),high power (40X), and oil immersion(100x)

Carbohydrate, monosaccharides, diasaccharides, Maltose, polysaccharides what they Are Made Up.

CARBOHYDRATE
there are three main type of carbohydrate namely the monosaccharides or simple sugars. The diasaccharides or double sugar and polysaccharides such as starch and cellulose shows how they related.
In everyday usage "sugar" means household sugar used to sweeten drinks and foods. This is sucrose which is a diasaccharides. Chemist and biologist use the term "sugar more widely to include all monosaccharides, diasaccharides and other carbohydrate which like sucrose, are sweet-tasting and soluble in water.
carbohydrate are made up of the elements such as carbon, hydrogen, and oxygen. They have the general formula Cx(H20)y; x and y can have any value, but there are always twice as many hydrogen atoms as oxygen atoms in a carbohydrate molecule.

MONOSACCHARIDES
general formula CH2O. Glucose and fructose are example of monosaccharides (monos, single and sacharon means sugar). Both have same formula; C6H12O6 but the atoms are arranged differently in their respective molecules. Monosaccharides are common in nature. They are found in honey and many different succulent fruits and give their sweet taste. Glucose is sometimes called blood sugar, for it is the form in which carbohydrate are carried in blood vertebrates.
Simple sugar taste sweet (though less so than diasaccharides) are soluble in water, and diffuse quickly. Most cell use glucose in respiration and it is commonest product of photosynthesis

DIASACCHARIDES
(general formula C12H22011). In the common diasaccharides, each molecule is formed by condensation of two monosaccharides molecule examples of diasaccharides include the following

SUCROSE (cane sugar or household sugar) is the form in which carbohydrate are generally transported in flowering plant. It is extracted commercially from sugar cane and sugar beet. A sucrose with one fructose molecule
Lactose (milk sugar) is present in the milk of mammals, including human beings and  cows.

MALTOSE is an intermediate product in the break down of starch to monosaccharides. For example it is formed in germinating seeds, and during mammalian digestion.
Diasaccharides are colourless, crystalline sub-stances. They are about three times more soluble than monosaccharides, but diffuse more slowly. They are easily hydrolyzed to simple sugars.

Polysaccharides
(general formula: Cn(H20)n¯¹ where n is usually between 200 and 500)
Polysaccharides (Gk: poly many) molecules are much lager than those of sugars because each is formed by the condensation of several hundred monosaccharide molecule. Polysaccharides are generally insoluble in water and are therefore the form in which plant and animals store carbohydrate. Biologically important Polysaccharides include the following: STARCH is found as granules in the cell of most plant organ like yam, cassava, grain and many seeds.
Glycogen, or animal starch is the form in which animals and fungi store carbohydrate. Both starch and Glycogen can be readily hydrolysed to glucose (the simple sugar unit from which each is made) as the plant or animal needs them.
CELLULOSE is the basic material of plant cell walls.
CHITIN is the basic material of insect exoskeletons.
Cellulose and chitin are chemically inactive they do not react with most other substances) this is a useful property in a protective covering.

LIPIDS (lipos,fat) is the collective name for fat and oils like carbohydrate molecules, lipids molecules consist of carbon, hydrogen and oxygen atoms. However, in them the proportion of oxygen is much lower typical formulae are C57H104O (palm oil) and C57H110O6 (beef fat). A lipid is formed when a glycerol molecule combines with fatty acid molecules, as shown
Fat and oil are insoluble In water but form emulsion in the presence of certain substances, called emulsifying agents. Washing-up lipid and bile salts are example of these. An emulsion consist of very tiny droplets of one liquid suspended in another. The droplet remain suspended because they are too small to settle.