Modern biotechnology
(i) There are two main features of this technology, that differentiated it from the conventional technology are its
i) ability to change the genetic material for getting new products with specific requirements through recombinant DNA technology
ii) ownership of the newly developed technology and its social impact.
(ii) Modern biotechnology embraces all methods of genetic modification by recombinant DNA and cell fusion technology.
The major focus of biotechnology are
(i) Fermentation for production of acids, enzymes, alcohols, antibiotics, fine chemicals, vitamins and toxins
(ii) Biomass for bulk production of single cell protein , alcohol, and biofuel
(iii) Enzymes as biosensors, in processing industry
(iv) Biofuels for production of hydrogen, alcohol, methane
(v) Microbial inoculants as biofertilizer, and nitrogen fixers
(vi) Plant and animal cell culture for production of secondary metabolites, monoclonal antibodies
(vii) Recombinant DNA technology for production of fine chemicals, enzymes, vaccines, growth hormones, antibiotics, and interferon.
(viii) Process engineering - tools of biotechnology is used for effluent treatment , water recycling.

(a) 'psy' gene is obtained from Daffodil plant (Narcissus pseudonarcissus).
(i) 'crt-l ' gene is from Erwinia uredovora bacterium.
(ii) 'lyc' gene is from wild-type rice endosperm.
(b) Golden rice can control Xerophthalmia.

A. Plasmid
B. rDNA / chimeric DNA

(i) PEG - Poly Ethylene Glycol
(ii) PHB - Poly Hydroxy Butyrate

Bt cotton has some limitations:
(i) Cost of Bt cotton seed is high.
(ii) Effectiveness up to 120 days after that efficiency is reduced.

Cosmid, plasmid, Bacteriophage and Phagemids.

Flush End	Cohesive End
Some restriction enzymes cut the strands of DNA through the centre resulting in blunt end or flush end or symmetric cuts.	Some restriction enzymes cut the strands in a way producing protruding and recessed ends known as cohesive end or sticky end or asymmetric cuts.

A restriction enzyme or restriction endonuclease is an enzyme that cleaves DNA into fragments at or near specific recognition sites within the molecule known as restriction sites.

When microbes are cultured, they secrete some enzymes into the growth media. These enzymes are industrially used in detergents, food processing, brewing and pharmaceuticals.
E.g. Protease, amylase, isomerase, and lipase.

Fermentation refers to the metabolic process in which organic molecules (normally glucose) are converted into acids, gases, or alcohol in the absence of oxygen or any electron transport chain with oxygen.

There are two main features of modem biotechnology, that differentiated it from the conventional technology are its:
(i) ability to change the genetic material for getting new products with specific requirement through recombinant DNA technology
(ii) ownership of the newly developed technology and its social impact.

Polyethylene Glycol (PEG) and Dextran Sulphate.

Restriction endonuclease. e.g: Hind II, EcoR I, Pvul, Bam H I, Taq I.

Spirulina can be grown easily on materials like waste water from potato processing plants (containing starch), straw, molasses, animal manure and even sewage, to produce large quantities.

(i) ECORI is from Escherichia ( E ) coli (co), strain RY 13 (R) & first endonuclease (I) to be discovered.
(ii) It contains 2 different antibiotics resistance genes & recognition site for several restriction enzymes.
(iii) This sequence is referred to as a restriction site & is generally -palindromic which means that the sequence in both DNA strands at this site read same in 5' - 3' direction & in-the 3'-5' direction.

(iv) The exact kind of cleavage produced by a restriction enzyme is important in the design of a gene cloning experiment.
(v) Some cleave both strands of DNA through the centre resulting in blunt or flush end.
(vi) These are known as symmetric cuts.
(vii) Some enzymes cut in a way producing protruding & recessed ends known as sticky or cohesive end.
(viii) These are known as staggered or asymmetric cuts.