1. During the preservation of microbial cell culture ______
a) metabolism stops
b) metabolism continues
c) metabolism changes
d) physiology changes
Explanation: The preservation of microbial cell culture does not alter the metabolism of microbes. Metabolism continues. The microbial culture is active viably and dividing during the preservation.
2. Which of the following method of preservation is more suitable and used widely?
a) Dried Cultures
b) Lyophilization
c) Salt Storage
d) Storage in liquid Nitrogen
Explanation: Lyophilization is the process of freeze-drying which involves sublimation of cell water and can be used to store culture for about 25 years.
3. Which of the following is not the composition of N-agar plates/ slants?
a) Yeast/Beef extract
b) Peptone
c) NaCl
d) Dextrose
Explanation: The nutrient agar plates contain yeast/beef extract, peptone, NaCl and Agar-Agar Powder. Dextrose is constituent of Potato Dextrose Agar.
4. Which of the following procedure has a great application in strain improvement?
a) rDNA Technology
b) Conjugation
c) Transformation
d) Transduction
Explanation: The applications of rDNA Technology have resulted in the improvement of strains and it has helped the organisms in producing products which they were not able to produce earlier.
5. The Induced mutations results in _________ formation.
a) A-A dimer
b) C-C dimer
c) T-T dimer
d) G-G dimer
Explanation: The mutations which are not spontaneous and are induced purposely on strain are called Induced mutations. It results in the formation of T-T dimers. T-T dimer results in the formation of hydrogen bonding between thymine bases.
6. Who isolated a biotin-requiring, Corynebacterium glutamicum?
a) Kinoshita
b) Nakayama
c) Nakao
d) Demain
Explanation: Kinoshita et al. isolated a biotin requiring, glutamate-producing, Corynebacterium glutamicum whose permeability was modified by the level of biotin.
7. When C. glutamicum was grown in a medium containing a high concentration of biotin, the amount of glutamate produced was ________
a) 10-40 µg/mg-1
b) 20-35 µg/mg-1
c) 25-36 µg/mg-1
d) 35-40 µg/mg-1
Explanation: When C. glutamicum was grown in a medium containing a high concentration of biotin, the amount of glutamate produced was 25-36 µg/mg-1. When the proper amount of biotin is used, about 50 µg/mg-1 of glutamate is produced.
8. α – ketoglutarate dehydrogenase normally converts _______ into _______
a) α – ketoglutarate, succinate
b) α – ketoglutarate, malate
c) α – ketoglutarate, glutamate
d) α – ketoglutarate, oxaloacetate
Explanation: α – ketoglutarate dehydrogenase normally converts α – ketoglutarate into succinate in the Tricarboxylic Acid Cycle (TCA) or citric acid cycle.
9. Who discovered the Gradient plate technique?
a) Sano
b) Shiio
c) Szybalski
d) Kubota
Explanation: Szybalski in 1952 discovered the Gradient Plate technique for exposing the survivors of mutation to a range of analogues. Gradient plate was useful in the isolation of drug and auxotrophic mutants.
10. The Replica plate technique was used for _________
a) Isolation of auxotrophs
b) Isolation of revertants
c) Isolation of analogue-resistant mutants
d) Isolation of prototrophs
Explanation: The Replica plate technique was used for the isolation of revertants. The isolation of auxotrophs and prototrophs proceeds with auxanographic technique and the isolation of analogue-resistant mutants is done by Gradient Plate technique.