Question

How many plasmids are present in bacterial cytoplasm?

Answer 1

Plasmids are the extrachromosomal region of DNA which are capable of self-replicating. The plasmids carry several genes which are useful for the survival of organisms as they provide resistance against antibiotics. Plasmids are an important tool in biotechnology. They are mostly present in prokaryotic bacteria.

Complete answer:
The plasmids are the circular double-stranded DNA molecules found in bacteria. They are the extrachromosomal DNA that is present in the cytoplasm. Some Archaea also possess plasmids. The chromosome has genes that are essential for the living of the organism whereas the plasmids have genes that provide additional advantages to the organism like antibiotic resistance. The plasmids are the naked DNA.

The plasmid DNA re capable of replicating independently. They have a segment of DNA that acts as an origin of replication. They can be transferred from one bacterium to another by the process of conjugation. The plasmids are present in the bacterial cytoplasm can range from a single plasmid to several hundred. The size of the plasmids varies from 1 to 100kb. The larger size plasmids have a low copy number as compared to that of smaller ones.

The plasmids carry genes that may be the virulence factor that helps the bacterium to colonize or the nif gene which helps in fixing nitrogen.

The plasmids can occur as single or several hundred in the bacterial cytoplasm.

Note: The plasmids are an important tool used for genetic engineering. They are used as vectors for carrying the desired genes and incorporating them into the target organism. Synthetic plasmids are also widely used for genetic engineering.