Describe briefly the following :
(a) Origin of replication
(b) Bioreactors
(c) Downstream processing .

Explanation

(i) Origin of Replication: This is the esquence in DNA molecule, from where, replication starts and any piece of DNA when linked to this seqyence can be made to replicate within the host cell.
(ii) Bioreactors: These are culture vessels in which large volume ( 100- 1000 litres) of culture can be processed to get large quantity of a product on a commercial scale.
(iii) Downstream processing: After the formation, a product undergoes through some processes before a finished product is ready for marketing. These processes include separation and purification which are collectively called as downstream processing.