Most Important Microbiology MCQ's.
Microbiology is the branch of botany concerned with the scientific study of microbes. Microbiologists are people who have an active interest in observing, recording, classifying or researching microbes. In this article, we will explore 40 multiple-choice questions (MCQ) related to microbiology to test your knowledge. Enjoy the journey through time as we delve into the fascinating world of microbes!
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1. Which one of the following 𝝺 proteins acts both as an activator and repressor of transcription ?
a. cl protein
b. N protein
c. cll protein
d. Q - protein
Answer : a. cl protein
2. One of the mechanisms used by bacteria for adaptation to changed environment is altering transcription of their genes. In this regards, which one of the following responses is NOT found in bacteria ?
a. A gene with two different promoters for expression in different condition.
b. Use of different sigma factors for transcription of genes.
c. Expression of alternate 𝛂, 𝜷 and 𝜷' subunits
d. Expression of anti-sigma factors
Answer : c. Expression of alternate 𝛂, 𝜷 and 𝜷' subunits.
3. Influenza virus (IV), a well known enveloped animal virus, enters its host cells through membrane fusion process catalyzed by haemagluttinin (HA) protein inside endosomes at 37°C. HA is localized in the lipid bilayer membrane of the IV as an integral membrane protein and is responsible for binding, and fusiion of IV is internalized into host cells through receptor medicated endocytosis followed by fusion of the IV membrane with endosome membrane catalyzed by HA. In a situation, if we wish to fuse IV membrane with its host cells (deficient in endocytosis) at the plasma membrane, mention the correct condition out of the following :
a. Pre-treat IV in pH 5.0 followed by its binding and fusion with host cells at pH 7.4 and 37°C.
b. Allow the IV to bind and fuse with host cells at pH 7.4 and 37°C.
c. IV and host cells are allowed to bind and fuse at pH 5.0 and 37°C.
d. IV is subjected to incubation at 60°C for 30 minutes and allowed to bind and fuse with host cells at pH 5.0 and 37°C.
Answer : c. IV and host cells are allowed to bind and fuse at pH 5.0 and 37°C.
4. Which of the following statements is NOT true regarding the closer affinity of Archaea to Eukarya than to Bacteria ?
a. Both Archaea and Eukarya lack peptide - glycan in their cell walls.
b. The initiator amino acid for protein synthesis is methionine in both Archaea and Eukarya.
c. Histones associated with DNA are absent in both Archaea and Eukarya.
d. In both Archaea and Eukarya the RNA polymerase is of several kinds.
Answer : c. Histones associated with DNA are absent in both Archaea and Eukarya.
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5. The aroma of freshly ploughed land at certain times of the year is probably due to
a. Bacteria
b. Actinomycetes
c. Yeast
d. Algae
Answer : b. Actinomycetes
6. Which of the following is a free living aerobic nitrogen-fixing bacteria ?
a. Azotobacter
b. Cyanobacter
c. B. circulans
d. None of these
Answer : a. Azotobacter
7. Satelite RNAs (sat - RNAs) are species of RNA associated with specific strains of ssome plant RNA viruses, although it is not necessary for their replication. Few statements are given below on sat - RNA
A. Presence of sat - RNA leads to reduction in severity of disease symptoms.
B. Presence of sat - RNA leads to increase in severity of disease symptoms.
C. sat-RNA is not consitutively expressed like coat proteins but is expressed like coat proteins but is expressed only after virus infection.
D. sat-RNA is not constitutively expressed like coat proteins but is expressed like coat proteins but is expressed only after virus infection.
Which one of the following combinations of above statements regarding sat-RNA is correct ?
a. (A) and (B)
b. (B) and (C)
c. (C) and (D)
d. (A) and (D)
Answer : d. (A) and (D)
8. Which one of the following influenza A virus subtypes caused severe avian flu and was responsible for disease outbreak in the year 1997 in Hong Kong ?
a. H1N1
b. H7N7
c. H3N2
d. H5N1
Answer : d. H5N1
9. Which of the following bacteria has subcellular localization in lysosomes ?
a. Salmonella typhi
b. Streptococcus pneumoniae
c. Vibrio cholerae
d. Mycobacterium tuberculosis
Answer : d. Mycobacterium tuberculosis
10. It takes 40 minutes for a typical E. coli cell to completely replicate its chromosome. Simultaneous to the ongoing replication, 20 minutes of a fresh round of replication is completed before the cell divides. What would be the generation time of E. coli growing at 37°C in complex medium ?
a. 20 minutes
b. 40 minutes
c. 60 minutes
d. 30 minutes
Answer : a. 20 minutes
11. An antibiotic that resembles the 3'end of a changed tRNA molecule is :
a. Streptomycin
b. Sparsomycin
c. Puromycin
d. Tetracycline
Answer : c. Puromycin
12. A culture medium contains two carbon sources, one is preferred carbon source (glucose) and the second is a non - preferred source (lactose). Which one below is correct regarding the nature of growth curve of E.coli cultured in this medium ?
a. Growth curve will be same as when grown in presence of only glucose.
b. Growth curve will be observed between the two exponential phases.
c. A lag phase will be observed between the two exponential phases.
d. Two lag phases will be observed between the two exponential phases.
Answer : c. A lag phase will be observed between the two exponential phases.
13. Entry of enveloped viruses into its host cells is mediated by :
a. Only endocytosis
b. Both endocytosis and phagocytosis
c. Both endocytosis and membrane fusion
d. Only pinocytosis
Answer : c. Both endocytosis and membrane fusion
