Aug 18, 2013

Biology for the Welfare of Mankind

During the past few decades research in the basic science of biology has yielded amazing knowledge. Application of biological knowledge has changed our lives in many ways. Humans are an integral part of the living world. Human beings have applied knowledge of biological science for the welfare of mankind. We will discuss few examples of historical and current endeavors.

Principles of Genetics
By using principles of genetics, new better varieties of wheat, rice, corn, chicken, cow and sheep have been developed poultry breeders have developed broilers for getting quick and cheap white meat. Genes of disease resistance and other desirable characters have been introduced into plants by using the techniques of genetic engineering. Plants having foreign DNA incorporated into their cells are called transgenic plants.

The plants can be propagated by cloning, using special techniques called tissue culture techniques etc. it is a technique in which a tissue is cultured to form a new plant e.g. A phloem tissue of an ordinary commercial carrot was removed and placed in a germ-free medium containing an adequate food supply, mineral salts, and growth substances. The cell developed into a complete carrot plant, which flowered and produced seeds.
Tissue Culture 

The chemicals which are used for killing the pests are called pesticides. Many fungi cause diseases in plants which are controlled by using fungicides. Insect pests that cause a great loss of plants and plant yield are controlled by using insecticides. Use of pesticides are harmful to animal life including human beings. It is also an environmental pollution. Insects and fungi may become resistant to the chemicals used. Now some bacteria are being used as biopesticides, to control the pollution caused by pesticides.


Plants are grown with their roots in dilute solutions of mineral salts instead of soil. This technique has been named as solution or water culture techniques. This water culture technique for growing plants with their root in a recirculating water solution is hydroponics. By this process exact and controlled amount of elements can be provided to plants. This method helps to determines inorganic nutrients required for the growth and development of plants.
Vegetable grown by hydroponics method

Food preservation
Food is preserved by using different techniques like drying, freezing, sterilization, chemicals and heat. Killing of bacteria by heat is called pasteurization, developed by Louis pasture. Milk and milk products are preserved by this method.

Disease control
There is a great success in the control of diseases. Three ways are generally taken to combat various diseases.

1. Preventive measures   
2. Immunization
3. Drugs treatment

Preventive measures
Prevention is better than cure.  Malaria can be prevented by using nets in doors and windows to ward off mosquitoes. By knowing the cause many diseases can be prevented easily. For example AIDS (Acquired Immuno Deficiency Syndrome) is caused by HIV (Human Immunodeficiency Virus). This disease spreads through free sexual contacts, through blood transfusion, by using contaminated syringes or surgical instruments. The best way of prevention from these diseases is to avoid the point of contact.                                                                                
By immunization we are able to save millions of lives. Peoples use to die or suffer from diseases like tetanus, polio, hepatitis, whooping cough, measles; mumps etc. Immunization involves the using of vaccines. By vaccination many diseases have been controlled or even eradicated e.g. small pox. Polio has been effectively controlled in Pakistan by massive campaign like observing polio days for vaccination of children.
Drug treatment
1. Antibiotics:  An antibiotic is a substance that is produced by an organism and inhibits or retards the growth of the microorganisms. Thousands of people used to die during war by infections. By using of antibiotics precious lives have been saved. Penicillin, streptomycin are the common examples of antibiotics.

2. Chemotherapy: With the increasing knowledge of biological science treatment of fatal diseases like cancer is possible. Chemotherapy is the treatment of infectious diseases or cancer by means of chemical compounds. Likewise cancer is also treated by radiation e.g. X-rays etc. The treatment by radiation is called radiotherapy. Repair of the defective gene is performed by isolating the normal gene and inserting it into the host through the bone marrow. This is called gene therapy.

A clone is an individual having identical genetic make-up like its parent. Cloning is possible with many plants because asexual propagation by cutting and grafting is relatively easy, and has been common practice. With this procedure and have orchard of uniform plants. Cloning in frog, mice, cows have been successful. In 1997 a sheep named Dolly has been cloned in Scotland which has been killed in early 2003 due to her illness.

During the process of cloning in animals the nucleus from a fertilized egg is removed. Then a nucleus from a cell of fully developed individual (donor) is inserted to the non-nucleated fertilized egg. The altered zygote is where it completes its development. The animal formed is genetically identical to animal whose nucleus was used. Thus by cloning multiple copies of a desired animal or genotype can be made.

    The cloned sheep-dolly with her lamb bonnie   

Biological Control and Integrated Disease Management

In biological control experiments, specialized predators are introduced into an environment in an attempt to reduce population of certain pests or disease causing organisms. For example to control the snake population in Islamabad mongoose have been introduced. As a result the number of snakes has reduced in Islamabad. World Health Organization (WHO) looks after the management, control and eradication of diseases all over the world. Some diseases have been irradiated e.g. smallpox. Many diseases are under control e.g. malaria. There is a ministry of health in federal Government and in provincial Governments, which looks after disease management in Pakistan e.g. vaccination against polio all over Pakistan. Diseases are also treated and control through Government Hospitals, dispensaries, private hospitals and clinics. Combating of disease by utilizing all methods as and when required and ensuring a participation of community in the program is called integrated disease management. This requires an awareness of the community about the severity of the problems, its causes and remedies.

immunization campaign

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