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

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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

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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

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11. The protoplast can be used to
A.modify genetic information
B.create plant hybrid
C.study plant viral infections
D.all of these

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12. Which of the following is incorrect?
A.Mammalian cells are larger and more complex than microorganisms
B.Their growth rate is very fast compared to microorganisms
C.Mammalian cells are fragile
D.Most animal cells only grow when attached to surface

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13. The size of a single plant cell is usually within the range of
A.10-20μm in diameter and 25-100μm long
B.20-40μm in diameter and 100-200μm long
C.40-60μm in diameter and 200-300μm long
D.60-80μm in diameter and 300-400μm long

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14. Which of the following is incorrect?
A.Plant cells are larger than the bacterial or fungus cells
B.Plant cells tend to grow in clumps
C.Plant cells are less sensitive to shear than microbial cells
D.Plant cells are more genetically unstable than microbial cells

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