Which bioreactor design is most suitable for large-scale mammalian cell culture in pharmaceutical industries?
Answer: C
Stirred-tank bioreactors with integrated aeration and agitation systems are ideal for industrial-scale mammalian cell culture, offering better control and scalability.
Q.22Medium
In continuous culture systems, the dilution rate (D) is defined as:
Answer: B
Dilution rate (D) = flow rate (F)/culture volume (V). In chemostat culture, growth rate equals dilution rate at steady state.
Q.23Medium
What is the primary disadvantage of using animal serum in cell culture for biopharmaceutical production?
Answer: B
Animal serum is costly, batch-to-batch variability is high, regulatory concerns exist, and it complicates downstream processing. Industries are shifting to serum-free media.
Q.24Medium
Which of the following statements is correct regarding cryopreservation of cell cultures?
Answer: B
DMSO and glycerol are cryoprotectants that prevent ice crystal formation and cell damage. Cells are stored at -196°C in liquid nitrogen. Rapid thawing is recommended.
Q.25Medium
In the context of cell culture, what is meant by 'passage number'?
Answer: A
Passage number indicates how many times cells have been subcultured/transferred. Higher passage numbers may result in senescence and altered cell characteristics.
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Q.26Medium
Which gas composition is typically maintained in mammalian cell culture bioreactors?
Answer: B
5% CO2 maintains pH through bicarbonate buffering, 5% O2 provides aerobic respiration, and N2 balances the gas mixture. This mimics physiological conditions.
Q.27Medium
What is the primary application of perfusion culture in modern biopharmaceutical manufacturing?
Answer: B
Perfusion culture continuously removes metabolic waste and supplies fresh medium while retaining cells, resulting in higher cell densities and productivity compared to batch culture.
Q.28Medium
In Indian biotech industries producing recombinant insulin, which cell line is predominantly used?
Answer: B
While CHO cells are used for complex proteins, E. coli is the primary system for insulin production in Indian industries due to cost-effectiveness and regulatory acceptance. However, CHO is also important for other biologics.
Q.29Medium
Which of the following is a characteristic feature of suspension culture compared to adherent culture?
Answer: B
Suspension cultures (used for hybridomas, CHO cells) allow cells to grow freely, achieve higher densities, and scale more easily than adherent cultures which require surface attachment.
Q.30Medium
What is the purpose of using microcarriers in animal cell culture?
Answer: B
Microcarriers (Cytodex, Microcarrier, etc.) provide surface area for anchorage-dependent cells in suspension bioreactors, combining advantages of both culture systems.
