Which hormone is most critical for cell growth and proliferation in serum-containing culture media?
Answer: C
Fetal Bovine Serum (FBS) contains essential growth factors, hormones, and attachment factors that promote cell growth and proliferation in culture.
Q.2Medium
What is the significance of calculating the cell doubling time in cell culture?
Answer: B
Cell doubling time indicates the rate at which cells divide and reflects their growth kinetics and overall health. It's calculated from exponential growth phase data.
Q.3Medium
Which of the following is NOT a method for cryopreservation of cell cultures?
Answer: D
Heating damages cells. Proper cryopreservation uses liquid nitrogen (-196°C) with cryoprotectants like DMSO or glycerol to prevent ice crystal formation that damages cell membranes.
Q.4Medium
What is the Hayflick limit?
Answer: B
The Hayflick limit describes the maximum replicative potential of normal human cells (~50-70 divisions) due to telomere shortening, after which cells enter senescence.
Q.5Medium
Which technique is used to determine cell viability immediately after thawing from cryopreservation?
Answer: B
Trypan blue is a vital dye that enters dead/damaged cells but is excluded by viable cells with intact membranes, allowing quick assessment of post-thaw viability.
Advertisement
Q.6Medium
What is the primary advantage of using serum-free media in cell culture?
Answer: C
Serum-free media have defined, known compositions without variable components of serum, providing better reproducibility in research and reducing lot-to-lot variability.
Q.7Medium
Which of the following best describes contact inhibition in normal cell cultures?
Answer: A
Contact inhibition is a regulatory mechanism where normal cells cease dividing once they form a complete monolayer and contact neighboring cells, unlike transformed cells.
Q.8Medium
An animal cell culture shows signs of contamination with bacteria. Which characteristic would NOT be observed?
Answer: C
Bacterial contamination typically causes increased acidity, turbidity, and odor but suppresses mammalian cell growth due to competition and toxins. Mammalian cell division rate would decrease, not increase.
Q.9Medium
What is the optimal CO₂ concentration typically maintained in mammalian cell culture incubators?
Answer: B
5% CO₂ is standard in mammalian cell culture incubators. It helps maintain pH (7.2-7.4) by forming a carbonate buffer system with bicarbonate in the medium.
Q.10Medium
Which of the following applications of cell culture is most relevant for drug testing in India's pharmaceutical industry (2024-2025)?
Answer: B
Cell culture is crucial for pharmaceutical companies in India to conduct in vitro drug screening and toxicity testing, reducing reliance on animal testing per regulatory guidelines.
Q.11Medium
Which parameter is most critical for maintaining pH stability in a large-scale bioreactor?
Answer: B
The bicarbonate-CO₂ buffering system is essential in bioreactors to maintain physiological pH (around 7.2-7.4) as cells metabolize nutrients and produce waste products.
Q.12Medium
What is the significance of cryopreservation in cell culture banking?
Answer: B
Cryopreservation using liquid nitrogen or cryoprotectants like DMSO allows cells to be stored long-term while maintaining viability and genetic stability for future use.
Q.13Medium
In the context of Indian pharmaceutical biotech (2024-25), which cell line is most commonly used for recombinant protein production?
Answer: A
CHO cells are the industry standard for recombinant protein production due to their high productivity, proper protein glycosylation, and regulatory acceptance globally and in India.
Q.14Medium
Which of the following best describes the G0 phase in the cell cycle?
Answer: C
G0 (G-zero) represents the quiescent state where cells are metabolically active but not dividing. Cells can exit G1 phase and enter G0 under nutrient limitation or other stress conditions.
Q.15Medium
What is the primary advantage of using suspension culture systems over adherent culture for large-scale production?
Answer: B
Suspension cultures allow cells to grow at higher densities (up to 10^7-10^8 cells/mL) and are easily scalable in bioreactors, making them ideal for industrial production.
Q.16Medium
During scale-up of cell culture from 2L to 200L bioreactor, which parameter becomes increasingly challenging to maintain?
Answer: B
As bioreactor volume increases, maintaining uniform oxygen distribution and adequate mixing becomes exponentially more difficult, requiring optimized agitation and aeration strategies.
Q.17Medium
What is the primary function of osmolarity/osmotic pressure control in cell culture media?
Answer: B
Proper osmolarity (typically 280-320 mOsm/kg) maintains isotonic conditions, preventing cell swelling (hypotonic) or shrinkage (hypertonic), which would lead to cell damage.
Q.18Medium
In viral vaccine production using cell culture, which cell line is commonly used for influenza vaccine manufacturing?
Answer: A
MDCK cells are widely used for influenza virus propagation and vaccine production. They support high-titer viral replication and are approved for vaccine manufacturing.
Q.19Medium
What is the role of trypsin in cell culture preparation and maintenance?
Answer: B
Trypsin (0.05% typically) is a serine protease that digests proteins binding cells to culture vessels, allowing gentle detachment of adherent cells for subculturing.
Q.20Medium
Which of the following statements about lactate production in mammalian cell culture is correct?
Answer: B
Lactate accumulates as a metabolic byproduct and at concentrations >15-20 mM can inhibit cell growth and reduce productivity. Lactate management is crucial in fed-batch cultures.
