Question

The one which has largest genome size

• A. R
• B. F
• C. ${\mu }_4$
• D. $\lambda$

Answer 1

The correct option is A R

Genome size is usually measured in base pairs (or bases in single-stranded DNA or RNA). The C-value is another measure of genome size. A special plasmid called a fertility (F) factor plays an important role in conjugation. The F factor contains genes that encourage cellular attachment during conjugation and accelerate plasmid transfer between conjugating bacterial cells. R plasmid or resistance plasmid is a conjugative factor in bacterial cells that promotes resistance to agents such as antibiotics, metal ions, ultraviolet radiation, and bacteriophages. It has the largest genome size of about 117 kb length base pairs. Bacteriophage lambda vectors can complete their life cycles even if foreign DNA was inserted into a portion of its genome. A lambda molecule that is between 78% and 105% of wild-type length can be packaged. This is from 37 to 53 kb in length. The 2-mu plasmid of yeast has a mechanism which allows it to rapidly amplify its copy number without initiating multiple rounds of replication. Thus, the correct answer is option A.