Question

Which one of the following is used as a vector for cloning genes into higher organisms?
(A)Rhizopus nigricans
(B)Retrovirus
(C)Baculovirus
(D)Salmonella typhimurium

Answer 1

Hint: The vectors are DNA molecules that can keep up a foreign DNA component and duplicate inside the host cell. Vectors may be plasmids; bacteriophage, cosmids, phagemids, yeast artificial chromosomes (YAC), Bacterial Artificial Chromosomes (BAC); transposons, shuttle vectors, and viruses.

Complete answer:
Viral vectors are equipment commonly employed by molecular biologists to transmit genetic material into cells. This method can be conducted in vivo or cell culture (in vitro). Viruses have developed specialized molecular agents to efficiently transfer their genomes inside the cells they debase.
At the beginning of the infection, the surface glycoprotein envelope interacts with receptors on the surface of the target cell to attain entrance. When they get inside the cell, the single-stranded viral genome is transformed into linear double-stranded DNA by a virus-encoded reverse transcriptase. As the target cell goes through mitosis, the viral DNA integrates with the target cell DNA—at which point it is recognized as a provirus. It is this proviral DNA that is altered to form retroviral vectors for gene transfer.

Option (A)Rhizopus nigricans
This option is not correct.

Option (B)Retrovirus
The retrovirus comprises two samples of a single-stranded RNA genome with orderings known as a gag, pol, and env, which encrypt viral structural and catalytic proteins. These are enclosed by a glycoprotein envelope. It is this proviral DNA that is altered to form retroviral vectors for gene transfer.

Option (C)Baculovirus
This option is not correct.

Option (D)Salmonella typhimurium
This option is not correct.

Hence the correct answer is OPTION(B)

Note: Certain viruses are often manipulated as vectors because they can transmit the new gene by infecting the cell. The viruses are adapted so they can't cause disease when used in people. Some groups of viruses, such as retroviruses, transmit their genetic material (involving the new gene) into a chromosome in the human cell.