What is recombination DNA?

Answer 1

== == DNA fragments cannot function all by themselves. They must become part of the genetic material of living cells before the gene they contain can be activated. In the second step of genetic engineering, DNA fragments are made into part of the recipient cell's genetic material. This is done by combining DNA fragments with DNA from the recipient cell. For example, DNA fragments may be combined with bacterial DNA so that they can later be inserted into a bacterial cell. Bacteria often contain small circular DNA molecules known as plasmids in addition to their chromosomes. These plasmids can be removed from bacterial cells and cut with the same restriction enzyme used to produce the DNA fragments. The cuts made by the restriction enzyme produce matching "sticky ends" on the DNA fragments and the cut plasmids. These sticky ends are the sites at which a DNA fragment and a plasmid can be joined end to end, thereby forming a new plasmid that contains a piece of foreign DNA. The combined DNA formed by fusing a DNA fragment and a plasmid consists of parts from different kinds of organisms. In genetic engineering, molecules of combined DNA are known as chimeras because they are produced by combining DNA from different species. Combined DNA is also known as recombinant DNA, since DNA from two sources has been recombined to produce it.

Answer 2

RecombinationRecombinant DNA is formed when DNA is incorporated into other (different) DNA. Usually recombinant DNA is found in plasmids (recombinant plasmids), which are small circular DNA molecules separate from the bacterial chromosome.

One example of recombination occurs in transduction, where bacteriophages (viruses) carry and transfer bacterial DNA as a source of variation. Recombination occurs when the phage inserts its DNA in the bacteria and it is incorporated in the bacterial genome. The bacteria is then called a recombinant cell. Along with transduction is conjugation, where bacteria trade DNA through a sex pilus. One strand of the F plasmid in a bacteria is transfered to another. The transfered DNA then circularizes.

Recombination is also used extensively in biotechnology. Desired genes are mass-produced through cloning of bacteria, usually E. coli. Restriction enzymes cut up the DNA containing the desired gene as well as the DNA in the future recombinant cell. Because they're cut with the same restriction enzymes, the extracted gene can bond to the sticky ends of the bacterial chromosome. DNA ligase is then used to join the ends of the DNA to completely circularize it. As a result, you have a bacterial cell with a certain gene that is inserted into its genome; a recombinant plasmid. Because bacteria reproduce rapidly, scientists can generate millions of copies of the specified gene, usually for medical purposes. Recombinant DNA is DNA that has been formed artificially by combining constituents from different organisms.

Answer 3

Any DNA made artificially by joining some DNA sequences(DNA) cloned in a vector DNA.