Question

1) Describe the use of Small SubUnit ribosomal RNA (SSU rRNA) gene sequences for the identification of bacteria in microbial communities. 100 marks

2) Describe how the genetic content of a bacterium determines the bacterium’s activities and behaviours. 100 marks

Answer 1

Answers:-

1. The small subunit ribosomal rRNA gene is present wiwithin bacterial genome.This gene expresses the necessary protein for structure and consistency of bacterial ribosome.This bacterial ribosome consists of rRNA and protein formed after translation of mRNA carrying the genetic code transcribed from 16S rRNA gene.

This 16S rRNA gene is a marker and fingerprint for bacterial identification i.e. its sequence differs among bacteria.So , you can use its specific primer and the amplified PCR product can be electrophoresed via agarose gel and can be cut from agarose and sequenced easily.Comparison of this sequence of 16S rRNA gene with that stored in gene bank using Basic Local Search Tool.Ribosomal ribonucleic acid (rRNA) is the RNA part of the ribosome and is essential for protein synthesis in all living organisms. rRNA is one of the gene products present in all cells. (16S rRNA is highly conserved sequences in prokaryotes, which is approximately 1,500 bp long and contains nine variable regions interspersed between conserved regions.

2. The genome forms the basic genetic material for all organism. On the basis of the sequencing of polynucleotide on the genome determines the fitness or adaptation to its surrounding, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic trait. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gene–environment interactions. Thus, it is the controller of all the behavioral activities done by bacteria.