31. Sometimes cell lines can be cultured for such a long time that they apparently develop the potential to be subcultured indefinitely in vitro. Such cells lines are called

A. established cell lines
B. primary cell lines
C. secondary cell lines
D. propagated cell lines

32. Higher dissolved oxygen concentration in the culture media are toxic and lead to

A. DNA degradation
B. lipid peroxidation
C. metabolism of nutrients in culture media at a rate greater than that required for consumption
D. all of the above

33. Which of the following is the technique used for the embryo culture?

A. Organ cultures on plasma clots
B. Organ cultures on agar
C. Whole embryo cultures
D. All of these

34. The major problem associated with the isolation of free cells and cell aggregates from organs is that of

A. releasing the cells from their supporting matrix
B. inhibiting the cells from their supporting matrix
C. disintegrating the cells from their supporting matrix
D. none of the above