Recombinant DNA technology uses techniques to identify, isolate, and recombine DNA from different sources to introduce new characteristics into organisms. A key technique is DNA cloning, which produces unlimited copies of a DNA segment. Restriction enzymes cut DNA into small fragments to study individual genes, recognizing specific nucleotide sequences. Plasmids are naturally occurring extrachromosomal DNA that can replicate autonomously and are used to clone DNA fragments in host cells.

1. Answer:
Recombinant DNA Technology: It is the set of techniques that enables the DNA from different
sources to be identified, isolated, and recombined so that new characterstics can be introduced
into an organism. One of the main techniques in recombinant DNA technology is DNA cloning.
The DNA cloning produces an unlimited number of copies of a particular DNA segment (from a
single ancestral DNA molecule). The Recombinant DNA Technology was engineered by Stanley
Norman Cohen and Herbert Boyer in 1973.
The cell based DNA cloning involve following 4 steps:
1) Construction of recombinant DNA molecule: The hybrid DNA molecules are constructed by
in-vitro covalant attachment (ligation) of the desired DNA fragments to a replicon.
2) Transformation: The recombinant DNA molecules are transferred into host cells, in which the
chosen replicon can undergo DNA replication.
3) Selective propogation of cell clones: The targeted cells were propogated in the selective liquid
medium.
4) Isolation of recombinant DNA clones: The recombinant DNA clones are selectively isolated.
* The enzymes used in the recombinant DNA technology are basically of 4 types:
DNA polymerase, Nucleases, Restriction Enzymes, Isoschizomers
Restriction enzymes: Most naturally occuring DNA molecules are much larger than can be
readily analysed in the lab. To study individual gene and individual site on DNA, the large DNA
molecules must be broken into small (managable) fragments. This could be done using
restriction enzymes. The restriction enzymes are bacterial enzymess that able to cut double-
stranded DNA molecules (by cleaving the phosphodiester bonds) at a specific nucleotide
sequence, called a restriction site. The term restriction comes from the fact that these enzymes
restrict the entry of foreign DNA in the bacteria. There are some enzymes that cut a three base
pair sequence while others can cut four, six, and even eight base pair target sequence in a DNA
molecule, usually palindromic.
The naturally occurring restriction endonucleases are categorized into four groups (Types I, II
III, and IV) based on their composition and enzyme cofactor requirements, the nature of their
target sequence, and the position of their DNA cleavage site relative to the target sequence.
For example: the one widely used restriction enzyme, EcoRI, named because it was found in
certain strain of Escherichia coli and was the first (I) such enzyme found in that species.
Plasmids: Plasmid are naturally occuring cicular, extrachromosomal, autonomously replicating
DNA, present in many prokaryotic and few eukaryotic organisms. These are range in size from 1
Kbp to over 300 Kbp. The cloning vectors, replicating genetic element used to carry a fragment
of target DNA into a host cell for the purpose of cloning. The important features of a plasmid are

2. as follows:
Solution
Answer:
Recombinant DNA Technology: It is the set of techniques that enables the DNA from different
sources to be identified, isolated, and recombined so that new characterstics can be introduced
into an organism. One of the main techniques in recombinant DNA technology is DNA cloning.
The DNA cloning produces an unlimited number of copies of a particular DNA segment (from a
single ancestral DNA molecule). The Recombinant DNA Technology was engineered by Stanley
Norman Cohen and Herbert Boyer in 1973.
The cell based DNA cloning involve following 4 steps:
1) Construction of recombinant DNA molecule: The hybrid DNA molecules are constructed by
in-vitro covalant attachment (ligation) of the desired DNA fragments to a replicon.
2) Transformation: The recombinant DNA molecules are transferred into host cells, in which the
chosen replicon can undergo DNA replication.
3) Selective propogation of cell clones: The targeted cells were propogated in the selective liquid
medium.
4) Isolation of recombinant DNA clones: The recombinant DNA clones are selectively isolated.
* The enzymes used in the recombinant DNA technology are basically of 4 types:
DNA polymerase, Nucleases, Restriction Enzymes, Isoschizomers
Restriction enzymes: Most naturally occuring DNA molecules are much larger than can be
readily analysed in the lab. To study individual gene and individual site on DNA, the large DNA
molecules must be broken into small (managable) fragments. This could be done using
restriction enzymes. The restriction enzymes are bacterial enzymess that able to cut double-
stranded DNA molecules (by cleaving the phosphodiester bonds) at a specific nucleotide
sequence, called a restriction site. The term restriction comes from the fact that these enzymes
restrict the entry of foreign DNA in the bacteria. There are some enzymes that cut a three base
pair sequence while others can cut four, six, and even eight base pair target sequence in a DNA
molecule, usually palindromic.
The naturally occurring restriction endonucleases are categorized into four groups (Types I, II
III, and IV) based on their composition and enzyme cofactor requirements, the nature of their
target sequence, and the position of their DNA cleavage site relative to the target sequence.
For example: the one widely used restriction enzyme, EcoRI, named because it was found in
certain strain of Escherichia coli and was the first (I) such enzyme found in that species.
Plasmids: Plasmid are naturally occuring cicular, extrachromosomal, autonomously replicating

3. DNA, present in many prokaryotic and few eukaryotic organisms. These are range in size from 1
Kbp to over 300 Kbp. The cloning vectors, replicating genetic element used to carry a fragment
of target DNA into a host cell for the purpose of cloning. The important features of a plasmid are
as follows: