Biology and the Service of Mankind (F.Sc Biology) Part 1
The science of biology had been helping mankind in many ways in increasing food production; in combating diseases and in protecting and conserving environment. Biological advances in the field of food and health have resulted in high standard of living.
Plant production has been tremendously increased by improving existing varieties and developing new high-yield and disease – resistant varieties of plants and animals used as food.
Plant and animal breeders have developed, through selective breeding, using the principles of genetics, new better varieties of wheat, rice, corn, chicken, cow and sheep. Poultry breeders have developed broilers for getting quick and cheap white meat. Genes for disease resistance and other desirable characters are introduced into plant, using the techniques of genetic engineering. Such transgenic plants (plants having foreign DNA incorporated into their cells) can be propagated by cloning (production of genetically identical copies of organisms/cells by asexual reproduction) using special techniques such as tissue culture techniques etc. plant pathogenic fungi and insect pasts of crops which weaken the plants and reduce the yield had traditionally been controlled by using chemical fungicides and insecticides (pesticides). Use of these chemicals poses toxicity problems for human beings as well as environmental pollution. Moreover, there are chances of insects becoming resistant to the effect of these chemicals. Biological control (control by using some living organisms) eliminates all such hazards. In biological control, pests are destroyed by using some living organisms that compete with or even eat them up. An aphid that attacks walnut tree is being controlled biologically by a wasp that parasitizes this aphid.
Even some bacteria are being used as bio-pesticides. Effective control of a particular disastrous disease, or all the common diseases of a plant can be achieved by using all relevant, appropriate methods of disease control. Such an approach of disease control is called “integrated disease management”.
Soil is a complex medium. It is almost impossible to conduct experiments on nutrient requirements of plants by growing them in soil. Hydroponic culture technique is used to test whether a certain nutrient is essential for plant or not. In this technique the plants are grown in aerated water to which nutrient mineral salts have been added. Hydroponic farming, however, is yet mot feasible. Astronaut may use it for growing vegetables.
Different techniques of food preservation have been developed for protecting food from spoilage and for its use and transport over long distance without damaging its quality. One of these is Pasteurization, developed by Louis Pasteur. It is being widely used for preservation of milk and milk products.
Disease Control
There has been fantastic progress in the area of health and disease control. Three pronged actions are usually taken against various diseases.
- Preventive measures
- Vaccination/Immunization
- Drug treatment/Gene therapy
Preventive measures
The advances in biological sciences have provided us information about the causative agents of the diseases and their mode of transmission. For instance the AIDS (Acquired Immune Deficiency Syndrome) is caused by HIV (human immune deficiency contaminated syringes or surgical instruments etc. therefore, doctors advise us to take precautions on these fronts so that we do not contract the disease, which is at present incurable. Similarly hepatitis is caused by H.virus which is spread through blood transfusion by using contaminated syringes and surgical instruments etc. in this case also doctors advice us to be careful and avoid the point of contact.
