Genetic Engineering: THe methods of artificial synthesis of new genes and their subsequent "transplantation" in the genome of an organism or methods of correcting the defective genes is called genetic engineering. It is a kind of biotechnology. It involves transfer or replacement of genes. Har Govind Khorana developed the technique of synthesis of known sequence of nucleotide or gene in test tube.

Restriction enzymes
(i) EcoRI
(ii) Hind II
(iii) BamH I
(iv) Sal I

Bacterium Thermus aquaticus is a source of enzyme Tag polymerase. As it is a thermostable enzyme and work at high temperature, it is used to amplify DNA in vitro by PCR. The amplified fragment of desired DNA can be used to ligate with the vector for further cloning.

Penicillin is a secondary metabolite and secondary metabolites are produced only when the organism is under stress, i.e, due to shortage of nutrients or environmental stress, etc. In continuous culture, the nutrients are added at continuous intervals and it remains in exponential phase, therefore less penicillin is produced (organism is never under stress). This is why batch culture (nutrients are added once) rather than continous culture is used for production of penicillin.

The first letter of the name comes from the genus of the bacterium.
The second and third letters come from the name of the species of the prokaryote cell from where it is isolated.
The next letter comes from the strain of the prokaryote.
The Roman Numbers following these four letters indicate the order in which the enzymes were isolated from that strain of the bacterium, e.g. EcoRI is isolated from E. coli, R Y 13.

Polymerase Chain Reaction
Multiple copies of the desired gene or segment of DNA, can be synthesised in vitro using two sets of primers, the oligonucleotides that are complementary to the regions of DNA of the two strands and the enzyme DNA polymerase.
This enzyme extends the primers using the nucleotides provided in the reaction and the genomic DNA as the template.
For repeated amplification to be achieved, a thermostable DNA polymerase (Taq polymerase), extracted from the bacterium, Thermus aquaticus is employed; it remains active during the high temperature treatment used for denaturation and separation of the two strands.

Yes,it is possible to produce a human clone. Human cloning is the creation of a genetically identical copy of a human. The term is generally used to refer to artificial human cloning, which is the reproduction of human cells and tissues. Two commonly discussed types of theoretical human cloning are: Therapeutic cloning and reproductive cloning. Therapeutic cloning would involve cloning cells from a human, for use in medicine and transplants. Reproductive cloning would involve making entire cloned human, instead of just specific cells or tissues. .If the baby is a clone, its DNA will be an identical match of the woman who was said to be cloned. The baby will also look identical to the mother.

Small volume cultures cannot yield appreciable quantities of products. To produce these products in large quantities the development of 'bioreactors' was required where large volumes (100-1000 litres) of culture can be processed. Thus bioreactors can be thought of as vessels in which raw materials are biologically converted into specific products, using microbial, plant, animal or human cells or individual enzymes.
Role. A bioreactor provides the optimal conditions for achieving the desired product by providing optimum growth conditions (temperature, pH, substrate, salts, vitamins, oxygen). One of the most commonly used bioreactor is of stirring type. A stirred tank reactor is usually cylindrical or with a curved base to facilitate the mixing of the reactor contents. The stirrer facilitates even mixing and oxygen availability throughout the bioreactor. Alternatively air can be bubbled 1lhroughthe reactor. If you look at the figure closely you will see that the bioreactor has an agitator system; an oxygen delivery system, a foam control system, a temperature control system, pH control system, sampling ports so that small volumes of the culture can be withdrawn periodically.

1. Bioreactors can be considered as vessels in which raw materials are biologically converted into specific products using microbial, plant or human cells.
2. A bioreactor provides optimal conditions for achieving the desired product by I providing optimum growth conditions, pH, substrate salts, vitamins, oxygen, etc.
3. The commonly used bioreactors are of stirring type. A stirred-tank reactor is usually cylindrical or with a curved base to facilitate the mixing of the contents.
4. The stirrer facilitates the even-mixing and oxygen availability throughout the bioreactor.