Question

can anyone please help me answer these 3 biology questions?

20. The plate count method allows direct count of total cells growing on solid medium. A. True B. False 21. Which of the following is a statistical procedure for estimating the number of viable microorganisms in a sample? A. Electronic cell counting device B. Most probable number (MPN) C. Petroff-Hausser chamber D. Spectrophotometry E. Viable plate count 22. Which of the following is the most commonly used to estimate and compare cell densities in a culture? A. Electronic cell counting device B. Most probable number (MPN) C. Petroff-Hausser chamber D. Spectrophotometry E. Viable plate count

Answer 1

Ans:- 20) False

The plate count method is a indirect method used to measure cell density and reveal information regarding viable bacterial cells.

Direct counting method includes use of microscope to count cell

Ex:- hemocytometer

Ans:-21) statistical procedure to estimate viable microbes in culture is

E) Viable plate count

Also known as standard plate count .This method allows measurement of cell density and information ralated to viable microbes.

Ans:-22) method of choice to estimate and compare cell densities in a culture is

D) Spectrophotometry:-

It is based on turbidity .It measures all bacteria / cell biomass.

It is a method of choice to estimate cell densities in a culture.

Also used to compare cell densities of culture.