MCQ Bank
What is the primary purpose of labeling test tubes in the serial dilution process?
- A) Enhance aesthetics
- B) Speed up microbial counting
- C) Ensure sample traceability
- D) Identify microbial colonies
In the pore plate method, what volume is the micropipette set at for inoculation?
- A) 75 microliters
- B) 125 microliters
- C) 50 microliters
- D) 100 microliters
Lactose present in milk converted into which acid during formation of curd through fermentation process.
- A) Lactic acid
- B) Acetic acid
- C) nitric acid
- D) sulpheric acid
What is the optimum temperature for the growth of lactobacilli?
- A) 30–40 °C
- B) 10-20°C
- C) 20-27 °C
- D) 45-55°C
What is the purpose of incubating plates at room temperature for 72 hours, isolating Aspergillus?
- A) Reduce fermentation
- B) Speed up fermentation
- C) Enhance enzyme secretion
- D) Examine growth pattern
How does the examination under x10 and x40 objective lenses contribute to the isolation of Aspergillus ?
- A) Observe mycelial coloration
- B) Accelerate fermentation
- C) Increase magnification
- D) Identify fruiting bodies
Vinegar is a product of which type of fermentation
- A) Alcoholic fermentation
- B) Lactic fermentation
- C) Acetic fermentation
- D) submerged fermentation
Which microorganism is Well-known for the production of alcoholic beverages and baking.
- A) none of these
- B) yeast
- C) Virus
- D) bacteria
What contributes to yoghurt's unique texture and tangy flavor?
- A) Lactic acid interaction with lactose
- B) Lactic acid interaction with milk proteins
- C) Lactic acid interaction with milk lipids
- D) Lactic acid interaction with milk sugars
During the spreading, why is the plate place in front of a flame?
- A) Rapid solidification of agar
- B) Enhance bacterial growth
- C) Prevent agar evaporation
- D) Avoid contamination
How is the inoculum size of Lactic Acid Bacteria measured in the yoghurt samples?
- A) Enzyme concentration
- B) Gram staining
- C) CFU/mL
- D) pH level
What is the primary purpose of flame sterilization of the inoculating loop, in the streak plate method?
- A) Reduce loop temperature
- B) Prevent contamination
- C) Enhance microbial growth
- D) Improve agar texture
Acetic acid is a weak monoprotic acid. In aqueous solution, it has a pKa value of
- A) 4.5
- B) 4.7
- C) 4.6
- D) 4.4
Acetic acid bacteria (AAB) includes several genera and species and belong to the following family.
- A) Achromatiaceae Massart
- B) Bacillaceae Fischer
- C) Acetobacteraceae
- D) lactobacillus
What is the purpose of stirring the fermenting gruel during the fermentation process?
- A) Accelerate fermentation
- B) Mix steep water and millet
- C) Enhance coloration
- D) Increase spore production
Yeast is a unicellular fungus mainly classified under which class
- A) Pseudomonas
- B) Micrococcus
- C) Staphylococcus spp
- D) Ascomycetes
Which of the following method is used for the concentration of acetic acid?
- A) All of these
- B) Distillation
- C) Titration
- D) filtration
Which method is used for the Morphological and cultural examination of curd microorganisms.
- A) Gram’s staining
- B) Hemocytometer
- C) iodine test
- D) None of these
From which of the following source Saccharomyces cerevisiae can be isolated
- A) vegetables
- B) Water
- C) milk
- D) meat
Up to what percentage S. cerevisiae can tolerate ethanol concentrations
- A) 14%
- B) 15%
- C) 12%
- D) 13%