Bacterial Genetics

Bacterial Genetics

Introduction

Genetics is the study of heredity and variation to understand the cause of resemblance and differences between parents and their progeny. The term genetics was coined by William Bateson, a British biologist, in 1906.

The unit of heredity is the gene, a segment of deoxyribo-nucleic acid (DNA) that carries in its nucleotide sequence information for a specific biochemical or physiologic property. All hereditary properties are encoded in DNA. Hence, the chro-mosomal DNA plays an important role in the maintenance of character from generation to generation. Genes carry the information to code for all the necessary components and the actions of life. The genes at each cell division are replicated and a copy is transmitted to each daughter cell.

Although heritability and variations in bacteria have been observed from the early days of bacteriology, it was not known then that bacteria too obey the laws of genetics. It was not until the 1950s that DNA was recognized as the building material of genes.

Bacteria unlike eukaryotic cells (such as human cells) are haploid (1n), which means they have a single copy of each gene. In contrast, eukaryotic cells are diploid (2n); in other words, they have a pair of each chromosome and therefore two copies of each gene. The genotype of an organism is the specific set of genes it possesses.