21. In animal cell culture, particularly mammalian cell culture, transformation means
A. uptake of new genetic material
B. phenotypic modifications of cells in culture
C. both (a) and (b)
D. release of genetic information
22. How does CO2 help in cell metabolism during cell culture?
A. It participates in the de novo synthesis of purines and pyrimidines
B. Helps in the respiration of the cells
C. For monitoring the pH of the culture
D. All of the above
23. Which of the following is not the explantation technique?
A. Slide culture
B. Carrel flask culture
C. Roller test tube culture
D. Adherent primary culture
24. Cells which have undergone transformation frequently become
A. anchorage-independent
B. anchorage-dependent
C. stable
D. unstable
25. The range of optimum glucose concentration present in the culture media is
A. 5.5 – 55 mmol/litre
B. 55 – 75 mmol/litre
C. 75-105 mmol/litre
D. 105-150 mmol/litre