Bioreactorsdownstream Processing

Stirred-tank bioreactors have been designed for:
1. Addition of preservatives to the product
2. Purification of the product
3. Ensuring anaerobic conditions in the culture vessel
4. Availability of oxygen throughout the process

Which of the following is not a component of downstream processing?

1.	Separation	2.	Purification
3.	Preservation	4.	Expression

The process of separation and purification of expressed protein before marketing is called:

1. Downstream processing

2. Bioprocessing

3. Post-product processing

4. Upstream processing

During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out:

1.	Histones	2.	Polysaccharides
3.	RNA	4.	DNA

Which of the following statements is incorrect?

1.	Most commonly used bio-reactors are of stirring type.
2.	Bio-reactors are used to produce small scale bacterial cultures.
3.	Bio-reactors have an agitator system, an oxygen delivery system and foam control system.
4.	A bio-reactor provides optimal growth conditions for achieving the desired product.

Identify the part of a bio-reactor which is used as a foam braker from the given figure.

1.	D	2.	C
3.	A	4.	B