INTRODUCTION

Since Mendel’s work was rediscovered in 1900, geneticists have made startling advances which have led to a new era of DNA technology. Modem techniques enable desired substance, for example insulin. Not very long ago, people with insulin dependent they receive human insulin, a product of biotechnology. Since the 1980s, biotechnology has produced drugs and vaccines to cure human illnesses.

Bacteria.

Genetically, engineered bacteria have been used to clean up environmental pollutants, increase the fertility of the soil, and kill insect pests. Alternation in genotype. Biotechnology also extends beyond multicellular organisms. It is now possible to alter the genotype and subsequently the phenotype of plants and animals.

Gene therapy.

Indeed, gene therapy in humans, attempting to repair a faulty gene is already undergoing clinical trials. There are those who are opposed to manipulation of genes for any reason. Although, there have been no ill effects as yet, they fear the possibility of health and ecological repercussions in the future.

Cloning of a gene.

Cloning of genes produces many identical copies. Recombinant DNA technology is used when a very large quantity of a gene is required. The use of polymerase chain reaction (PCR) creates a lesser number of copies within a laboratory test tube.

Recombinant DNA Technology.

Recombinant DNA technology popularly known as genetic engineering aims at synthesizing recombinant DNA which contains DN