AP BIOLOGY

Detailed explanation-1: -Today most cloning is performed with plasmid vectors. The plasmid vectors most widely used for gene cloning are small circular molecules of double-stranded DNA derived from larger plasmids that occur naturally in bacterial cells.

Detailed explanation-2: -Researchers can insert DNA fragments or genes into a plasmid vector, creating a so-called recombinant plasmid. This plasmid can be introduced into a bacterium by way of the process called transformation. Then, because bacteria divide rapidly, they can be used as factories to copy DNA fragments in large quantities.

Detailed explanation-3: -In a typical cloning experiment, a target gene is inserted into a circular piece of DNA called a plasmid. The plasmid is introduced into bacteria via a process called transformation, and bacteria carrying the plasmid are selected using antibiotics.

Detailed explanation-4: -Plasmids contain three components: an origin of replication, a polylinker to clone the gene of interest (called multiple cloning site where the restriction enzymes cleave), and an antibiotic resistance gene (selectable marker).

Detailed explanation-5: -In general, cloning vectors are plasmids that are used primarily to propagate DNA. They replicate in E. coli to high copy numbers and contain a multiple cloning site (also called a polylinker) with restriction sites used for inserting a DNA fragment.