Question

Which of the following is not a genetic vector?
A. Plasmid          
B. Phage
C. Cosmid         
D. Virusoid

Answer 1

Hint: A vector is a DNA molecule that is used as a vehicle to carry a specific DNA segment into a host cell as part of a cloning or recombinant DNA method. The vectors are commonly characterised by three factors including multi-cloning sites, the origin of replication, and a selective marker.

Complete Step-by-step answer:
A genetic vector is a DNA molecule that is used as a vehicle for artificially transmitting foreign genetic material into another cell where it is stated. It can reproduce autonomously. The four main kinds of vectors are plasmids, cosmids, viral vectors, and artificial chromosomes. The most commonly used genetic vector is a plasmid. It is a tiny DNA molecule present in a cell that can reproduce independently. The other commonly used vectors are viruses and artificial chromosomes. A vector that contains foreign DNA is referred to as recombinant DNA.
Viroids are the smallest infectious pathogens. Viroid is composed exclusively of a short strand of circular, single-stranded RNA that has no protein coating. All the known viroids are inhabitants of higher plants and most cause diseases, whose respective economic importance to humans varies extensively. The size of viroids is smaller than that of viruses. The RNA is the genetic material of the viroid of low molecular weight.

Therefore the correct answer is Option D.
Note: Vectors are used as a tool in molecular cloning procedures to introduce the desired DNA insert into a host cell. The DNA insert that is transferred by a vector is known as recombinant DNA, and the process is also called recombinant DNA technology.