Self-Evaluation

Q1. Specific growth rate is defined as -
       (A)   1/X (dX/dt) where X is the Biomass concentration and ‘t’ is the time
       (B)   X (dX/dt)
       (C)   dX/dt
       (D)   1/dX/dt

Q2. Coulter counter apparatus can measure the -
       (A)   Total number of cells
       (B)   Live cells only
       (C)   Dead cells only
       (D)   Total mass of cells

Q3. The dye used for distinguishing the viability of the microbial cells is -
       (A)   Methylene Blue
       (B)   Typhan Blue
       (C)   Either Methylene Blue or Tryphan blue
       (D)   Mixture of Methylene Blue and Tryphan blue

Q4. The spores of the microorganisms -
       (A)   Are killed more easily than vegetative cells
       (B)   Are more resistant than the vegetative cells
       (C)   Mixture of spores and vegetative cells are more resistant to heat
       (D)   None of the above is true

Q5. Del factor is defined as -
       (A)   ln (N0/N) where N0 is initial number of cells before sterilization and N is the final
                     number of cells after sterilization
       (B)   ln (N/N0) where N0 is initial number of cells before sterilization and N is the final
                     number of cells after sterilization
       (C)   1/ln (N0/N) where N0 is initial number of cells before sterilization and N is the final
                     number of cells after sterilization
       (D)   None of the above is true

Q6. Decimal reduction time -
       (A)   Time required for reducing the microbial population by 1/10th of its original value.
       (B)   Time required to bring down the total living cell count as 10
       (C)   Time required to bring down the total cell count as 10
       (D)   None of the above is true

Q7. In a particular case the value of (N/N0) was 0.01 -
       (A)   It means that there is a probability of survival of one microorganism out of 100 after
                     the sterilization
       (B)   It means that there is a probability of contamination of one batch in 100 batches of
                     cultivation.
       (C)   Both A & B are true
       (D)   None of the above is true

Q8. The DEL factor -
       (A)   Increases with the increase in the fermenter volume
       (B)   Decreases with the increase in the fermenter volume
       (C)   Neither increases nor decreases with the increase in the fermenter volume
       (D)   None of the above is true

Q9. Disadvantages of batch sterilization are -
       (A)   Over exposure of the medium at elevated temperature
       (B)   Destruction of heat labile nutrients
       (C)   Both A & B are true
       (D)   None of the above is true

Q10. Advantages of batch sterilization are -
       (A)   Lower capital and equipment costs
       (B)   Lower risk of contamination
       (C)   Easier manual control
       (D)   All of the above