Question

Which of the following statement is true regarding plasmids?

• A. Plasmids are widely used in gene transfer.
• B. These are found in virus.
• C. Plasmid contains gene for vital activities.
• D. These are main part of chromosome.

Answer 1

The correct option is A Plasmids are widely used in gene transfer.

Plasmids are used to clone, transfer, and manipulate genes as vectors. A DNA segment, carrying the gene of interest can be inserted into a plasmid vector and recombinant plasmids are created. These plasmids are then introduced into a bacterium via transformation. Bacteria divide rapidly, hence large number of DNA fragments with desired genes are produced. A plasmid is small, circular, dsDNA molecule which is distinct from a cell's chromosomal DNA and are not the part of chromosome. Plasmids are naturally found in bacterial cells and also in some eukaryotes but not in virus. Plasmids carry the genes that confers genetic advantages to the bacterium, such as antibiotic resistance, the genes for vital activities are not found on it.
So, the correct answer is option A.