Microbiology MCQ-01
1. The process in which all living cells, spores and viruses are completely destroyed from an object is called _____.
a. Disinfection
b. Pasteurization
c. Sterilization
d. Antisepsis
2. UHT sterilization involves high temperature exposure of objects for _____.
a. 1 – 3 seconds
b. 1 – 3 minutes
c. 1 – 3 hours
d. 10 – 30 hours
Microbiology Notes | Microbiology PPT
3. _______ is an antiseptic.
a. Chlorine
b. Copper Sulphate
c. Ozone
d. 70% ethanol
4. Error rate of Taq DNA polymerase is _____
a. 10-4
b. 10-14
c. 10-24
d. 10-40
5. The best form of DNA to transform E. coli is ______.
a. Linear
b. Covalently closed
c. Nicked circles
d. Nicked linear
6. ______ phage is widely used for phage display technique.
a. M13
b. Φ6
c. λ phage
d. T7 phage
7. _____ RNA polymerase has a single subunit.
a. E. coli
b. Bacillus subtilis
c. T7
d. λ phage
8. Same DNA sequence may code for more than one protein by ______
a. Gene splitting
b. RNA splitting
c. Alternative splicing of RNA
d. None
9. Bacterial cells can be stained with ____ to reveal the presence of lipid inclusions.
a. Saffranin
b. Methylene blue
c. Trypan blue
d. Sudan dyes
10. Glucose that is taken in by a bacterial cell is made to stay within the cell by _______.
a. Attaching to membranes
b. Immediate utilization
c. Phosphorylation
d. Conversion to Fructose
11. Magnetosomes are inclusion of _____ in certain bacteria
a. Iron oxide
b. Iron phosphate
c. Iron nitrates
d. Iron chlorides
12. In a population of 1 X 10^8 bacterial cells, if there is 50% killing ______ number of cells would remain viable.
a. 0.5 X 108
b. 1 X 104
c. 50
d. 0.2 X 108
13. _____ is a predator bacterium that infects other gram negative bacteria.
a. Haemophilus influenza
b. Pseudomonas putida
c. Proteus mirabilis
d. Bdellovibrio
14. ______ are prokaryotic, but have the ability to carry out oxygenic photosynthesis.
a. Photorhizobium
b. Cyanobacteria
c. Chlorobium
d. Rhodospirillum
15. ______ is the only bacterial genus where sterols are present in the cell membrane.
a. Escherichia
b. Mycoplasma
c. Chlamydea
d. Vibrio
Answer Key and Explanations
1. Ans. (c). Sterilization
Sterilization: Removal of all microorganism irrespective of harmful or beneficial from an object. Reagents used usually not specific to microorganisms.
Disinfection: Removal of pathogenic or harmful microbes from the surface of an object by using specific reagents.
Pasteurization: A partial sterilization process of a liquid by treating the liquid for specific temperature for specific time interval which destroys the harmful microbes from the liquid without altering the chemical composition.
Antisepsis: killing pathogenic or harmful microbes by antiseptics
2. Ans. (a). 1 – 3 seconds
UHT: Ultra High Temperature Treatment, A sterilization method
UHT is a method of sterilization of food materials by heating at a temperature of 135oC (270oF) for 1 – 3 seconds. At this temperature the microbial spores in the food materials is eliminated. UHT treatment is commonly used in the pasteurization of milk.
3. Ans. (d). 70% ethanol
Antiseptic: an anti-microbial agent that applied to skin to prevent or reduced the possible infection
Commonly used antiseptic agents: 70% alcohol, Hydrogen peroxide, Iodine solution, Polyhexamide and sodium bicarbonate
4. Ans. (a). 10-4
Error rate of Taq DNA Polymerase: 1 in about 10000 nucleotides (1/10000). The high error rate is because of the fact that Taq DNA polymerase lack the 3′ to 5′ exonuclease proofreading activity.
5. Ans. (b). Covalently closed
6. Ans. (a). M13
Phage display technique: a method to study protein-protein or protein-DNA interactions.
Other phages used for phage display technique: T4, T7 phage, λ phage.
7. Ans. (c). T7 bacteriophage
T7 bacteriophage is highly promoter specific. It transcribe only downstream to T7 promoter.
8. Ans. (c). Alternative splicing of RNA
Alternate splicing: also called differential splicing.
9. Ans. (d). Sudan dyes
10. Ans. (c). Phosphorylation
Phosphorylated glucose is no recognized by the glucose transport system in the cells and thus they stay in the cell.
11. Ans. (a). Iron oxide
12. Ans. (a). 0.5 X 108
13. Ans. (d). Bdellovibrio
14. Ans. (b). Cyanobacteria
15. Ans. (b). Mycoplasma
Mycoplasma lacks cell wall around the plasma membrane.
How to give answer ?