8. Excess CO2 suppress cell growth and productivity by
A.inhibiting respiration
B.altering intracellular pH by diffusing across cell membrane
C.both (a) and (b)
D.altering pH of the medium

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9. Which of the following is incorrect?
A.Established cell lines (ECL) have short doubling time
B.ECL are invariably aneuploid
C.ECL grow in higher density
D.ECL do not show much evidence of spatial orientation

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10. What is the effect of excess accumulation of metabolite products (lactate and ammonium) on cells?
A.They act as growth promoters
B.They act as growth inhibitors
C.Have no effect on cells
D.Lactate helps in the growth while ammonium inhibits the growth

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11. What is the concentration of CO2 required for culturing animal cells?
A.2-5%
B.1-10%
C.10-15%
D.15-20%

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12. Which of the following is correct?
A.ECL can be established in suspension cultures whereas it is exceptional for primary cell lines (PCL)
B.ECL and PCL can be established in suspension cultures
C.PCL can be established in suspension cultures
D.none of the above

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13. Which of the followings are the metabolic products of glucose and glutamine?
A.CO2 and NH3
B.CO2 and lactate
C.Lactate and ammonium
D.Lactate only

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14. To prevent the accumulation of lactate
A.low glutamine concentration is required
B.high glutamine concentration is required
C.low glucose concentration is required
D.high glucose concentration is required

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