Question

Extrachromosomal DNA used as vector in gene cloning is

• A. Plasmid
• B. Exon
• C. Transposon
• D. Intron

Answer 1

The correct option is A Plasmid

Gene cloning
Gene cloning is a method of molecular biology used to make multiple copies of a particular gene of interest. The gene of interest is inserted into a self replicating vector DNA via genetic engineering to form a recombinant DNA (rDNA). The rDNA is then inserted into a host organism to make clones of the gene of interest.

Vector
Vectors are the DNA molecules which can carry the foreign DNA fragment into the host cells for cloning. Examples include plasmids.

Transposons
Transposons or jumping genes are nucleotide sequences that move from one location of the genome to another. They may cause mutations or reverse mutations. Transposons can be used as vectors in insertional mutagenesis. These genes are not present in extrachromosomal DNA.

Introns
Introns are the non-coding sequence of nucleotides in RNA. These introns are spliced before it is translated to form protein.

Exons
Exons are the coding sequence of nucleotides in RNA. They are translated to form proteins.

Plasmids
Plasmids are circular, extranuclear, double stranded, self replicating DNA molecules that are used as vectors for small fragments of DNA in the gene cloning process.

Final answer:
d. Plasmid