6. Balanced growth is defined as

A. cultures undergoing balanced growth while maintaining a constant chemical composition
B. balancing the growth while controlling the pH
C. balancing the growth while controlling the temperature
D. balancing the growth while changing the nutrient composition

7. Semi-solid media, prepared with agar at concentrations of 0.5% or less are useful for the cultivation of

A. Microaerophillic bacteria
B. Lactobacilli
C. E.coli
D. all of these

8. The cell mass can be measured optically by determining the amount of light scattered by a suspension of cells. The measurements are usually at a wavelength of

A. 300-400nm
B. 400-500nm
C. 500-600nm
D. 600-700nm

9. Which of the following is not an indirect method for the measurement of cell mass?

A. Nutrient composition
B. Cell dry weight
C. Viscosity
D. Heat evolution

10. Callus cultures are amorphous cell aggregates arising from the unorganized growth of explants on an

A. liquid medium
B. solid nutrient medium
C. aseptic solid nutrient medium
D. solid or liquid medium