Question

In recombinant DNA technique the term vector refers to
A. Donor DNA is identified and picked up through electrophoresis
B. Plasmids transfer DNA into living cell
C. Collection of entire genome in form of plasmids
D. Enzymes cut the DNA at specific sites

Answer 1

Hint:-Recombinant DNA, DNA molecules that are injected into the host organism from two separate organisms to create new genetic combinations that are of importance to science , medicine , agriculture and industry.

Complete Answer:-Since the gene is the subject of all genetics, laboratory geneticists' fundamental objective is to isolate, classify, and manipulate genes. There would be several kilometres of DNA in the small tissue sample. Recombinant DNA technology, however, has made it possible to isolate one gene or any other portion of DNA, allowing researchers to determine its nucleotide sequence, review its transcripts, mutate it in highly specific ways, and reinsert into a living organism the changed sequence.
The pre-arrangement of large numbers of similar DNA molecules is the core of recombinant DNA technology. A DNA fragment of interest is bound to a vector DNA molecule via normal phosphodiester bonds, which can replicate when inserted into a host cell. The inserted DNA is replicated along with the vector when a single recombinant DNA molecule, consisting of a vector plus an inserted DNA fragment, is introduced into a host cell, creating large numbers of recombinant DNA molecules.
When a single recombinant DNA molecule is introduced into the host cell, consisting of a vector plus an inserted DNA fragment, the inserted DNA is replicated along with the vector, creating a large number of recombinant DNA molecules that include the DNA fragment originally connected to the vector. A vector is a molecule of DNA used to move foreign genetic material into another living cell as a vehicle. Recombinant DNA is considered a vector containing foreign DNA. Plasmids, viral vectors, cosmids, and artificial chromosomes are the four primary types of vectors. Of these, plasmids are the most widely used vectors.

So, 'a plasmid transfer DNA into a living cell' is the correct alternative.

Note:- Plasmids are double-stranded , circular DNA molecules that are distinct from the chromosomal DNA of a cell. In a parasitic or symbiotic relationship with their host cell, these extrachromosomal DNAs, which naturally occur in bacteria , yeast, and some higher eukaryotic cells, exist.