Question

The prokaryotic structure credited for transfer of gene from one organism to another organism is

• A. Ribosome
• B. Mitochondria
• C. Plasmid
• D. Polysome

Answer 1

The correct option is C Plasmid

Plasmids are small, circular, supercoiled, double stranded extrachromosomal DNA; they require very few genes for their own replication and rest of their genes can be deleted and foreign sequences can be added to the plasmids. To move between different cells/organisms, plasmids have ori region that confers their replication in host and tra gene codes for transfer protein needed for transfer of plasmids from one cell to other. This makes option C correct. Mitochondria are double membrane bound eukaryotic organelles that serve as power house and are absent in prokaryotic cells; option B is incorrect. Ribosomes are the site for protein synthesis and have two subunit; large and small. Prokaryotic ribosomes have 30S and 50S subunits that together make a 70S ribosome. Large clusters of 10 to 100 ribosomes actively translating sequence of single mRNA into multiple copies of protein are called as polysomes. Thus, ribosomes and polysomes are not involved in gene transfer; options A and D are incorrect. Thus, the correct answer is option C.