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Question Bank

Microbiology - English

Duration: 60 · Questions: 50 · Max Marks: 50 · Language: 3

View Microbiology Exam Page

Microbiology

1
What is the primary function of a plasmid in a bacterial cell ?
  1. A.Energy Production
  2. B.Protein Synthesis
  3. C.Genetic Exchange
  4. D.Cell division
2
Which of the following is a characteristic feature of plasmids ?
  1. A.Single-stranded DNA
  2. B.Circular DNA
  3. C.Linear DNA
  4. D.RNA genome
3
Bacteriophages primarily infect which type of microorganism ?
  1. A.Bacteria
  2. B.Fungi
  3. C.Protozoa
  4. D.Archaea
4
The protein coat of a bacteriophage is called ?
  1. A.Capsid
  2. B.Envelope
  3. C.Nucleocapsid
  4. D.Liposome
5
Which of the following is a lytic cycle in bacteriophage replication ?
  1. A.Lysogenic
  2. B.Integration
  3. C.Attachment
  4. D.Bursting
6
Which enzyme is responsible for cutting the host DNA during bacteriophage integration in the lysogenic cycle ?
  1. A.DNA ligase
  2. B.DNA polymerase
  3. C.Restriction endonuclease
  4. D.Integrase
7
What is the name of the bacteriophage that infects E. coli and is commonly used in molecular biology research ?
  1. A.T4 phage
  2. B.Lambda phage
  3. C.Adenovirus
  4. D.Herpesvirus
8
Which type of plasmid carries genes that can cause antibiotic resistance in bacteria ?
  1. A.Fertility plasmid
  2. B.Resistance plasmid
  3. C.Virulence plasmid
  4. D.Conjugative plasmid
9
What is the process by which plasmids are transferred from one bacterium to another through direct cell-to-cell contact ?
  1. A.Transduction
  2. B.Transformation
  3. C.Conjugation
  4. D.Transcription
10
Which of the following is NOT a mechanism by which bacteria can acquire plasmids ?
  1. A.Transformation
  2. B.Conjugation
  3. C.Transduction
  4. D.Mitosis
11
What is the main function of the origin of replication (ori) in a plasmid ?
  1. A.Attachment to host DNA
  2. B.Initiation of plasmid replication
  3. C.Transfer of plasmid to other cells
  4. D.Integration into the host genome
12
Which term refers to the transfer of genetic material from one bacterial cell to another through the uptake of naked DNA from the environment ?
  1. A.Conjugation
  2. B.Transduction
  3. C.Transformation
  4. D.Replication
13
In which phase of the cell cycle is a bacterial cell most susceptible to transformation ?
  1. A.G1 phase
  2. B.S phase
  3. C.G2 phase
  4. D.Log phase
14
What is the role of the repressor protein in a temperate bacteriophage during the lysogenic cycle ?
  1. A.Promotes gene transcription
  2. B.Prevents viral replication
  3. C.Activates the lytic cycle
  4. D.Encapsidates the viral DNA
15
Which type of plasmid contains genes that enhance the fitness of the host bacterium but do not directly confer antibiotic resistance ?
  1. A.Resistance plasmid
  2. B.Fertility plasmid
  3. C.R plasmid
  4. D.Fitness plasmid
16
What is the term for the transfer of genetic material from one bacterium to another via a viral vector ?
  1. A.Conjugation
  2. B.Transduction
  3. C.Transformation
  4. D.Replication
17
Which enzyme is responsible for replicating the DNA of a bacteriophage within the host cell during the lytic cycle ?
  1. A.DNA ligase
  2. B.DNA polymerase
  3. C.RNA polymerase
  4. D.Reverse transcriptase
18
Which of the following is NOT a function of plasmids in bacteria ?
  1. A.Antibiotic resistance
  2. B.Toxin production
  3. C.Regulation of cell division
  4. D.Photosynthesis
19
In the process of conjugation, which structure allows for the transfer of plasmids from one bacterial cell to another ?
  1. A.Pili
  2. B.Flagella
  3. C.Capsule
  4. D.Endospore
20
Which of the following is a common mechanism by which bacteria can acquire antibiotic resistance genes on plasmids ?
  1. A.Mutation
  2. B.Sporulation
  3. C.Horizontal gene transfer
  4. D.Binary fission
21
Which bacteriophage type integrates its genome into the host chromosome and can become a prophage ?
  1. A.Lytic bacteriophage
  2. B.Temperate bacteriophage
  3. C.Virulent bacteriophage
  4. D.Retrovirus
22
In the lytic cycle of bacteriophage replication, what is the final step ?
  1. A.Lysis of the host cell
  2. B.Attachment to the host cell
  3. C.Integration into the host genome
  4. D.Replication of viral DNA
23
What is the function of the transposons in the bacterial genome ?
  1. A.Facilitate transformation
  2. B.Promote conjugation
  3. C.Promote transduction
  4. D.Allow for the movement of genes within the genome
24
Which of the following is a method used by bacteria to resist bacteriophage infection ?
  1. A.Capsule formation
  2. B.DNA replication
  3. C.Restriction-modification system
  4. D.Conjugation
25
What is the primary difference between a plasmid and the bacterial chromosome ?
  1. A.Plasmids are single-stranded, and the chromosome is double-stranded.
  2. B.Plasmids are linear, and the chromosome is circular.
  3. C.Plasmids are smaller and exist independently of the chromosome.
  4. D.Plasmids are part of the host genome, while the chromosome is extrachromosomal.
26
Which type of plasmid is involved in the transfer of genetic material between bacteria during conjugation ?
  1. A.Fertility plasmid
  2. B.Resistance plasmid
  3. C.Virulence plasmid
  4. D.Degradative plasmid
27
What is the name given to plasmids that can integrate into the bacterial chromosome ?
  1. A.Transposons
  2. B.Episomes
  3. C.Conjugative plasmids
  4. D.Fitness plasmids
28
Which of the following is a characteristic of a prophage ?
  1. A.It kills the host cell immediately.
  2. B.It replicates independently of the host chromosome.
  3. C.It integrates into the host chromosome.
  4. D.It only infects archaea.
29
What is the role of the primer in DNA replication ?
  1. A.It adds nucleotides to the growing DNA strand.
  2. B.It stabilizes the DNA strand.
  3. C.It initiates the synthesis of the new DNA strand.
  4. D.It proofreads the DNA strand for errors.
30
Which enzyme is responsible for unwinding the DNA double helix during DNA replication ?
  1. A.DNA polymerase
  2. B.DNA ligase
  3. C.Helicase
  4. D.Topoisomerase
31
Which phase of the bacterial growth curve is characterized by rapid cell division and a constant rate of cell death ?
  1. A.Lag phase
  2. B.Log phase
  3. C.Stationary phase
  4. D.Death phase
32
What is the primary function of the sigma factor in bacterial transcription ?
  1. A.Initiating DNA replication
  2. B.Promoting translation
  3. C.Recognizing the promoter sequence
  4. D.Proofreading MRNA
33
In bacterial conjugation, what structure allows for the transfer of DNA from a donor cell to a recipient cell ?
  1. A.Plasmid
  2. B.Pili
  3. C.Capsule
  4. D.Ribosome
34
In the context of plasmids, what is meant by "high copy number" ?
  1. A.The plasmid can replicate in both the donor and recipient cells.
  2. B.The plasmid is present in a large quantity within the cell.
  3. C.The plasmid is resistant to degradation by restriction enzymes.
  4. D.The plasmid contains a large number of genes.
35
Which type of plasmid allows for the transfer of DNA between different bacterial species?
  1. A.Conjugative plasmid
  2. B.Fertility plasmid
  3. C.Resistance plasmid
  4. D.Degradative plasmid
36
What is the role of reverse transcriptase in retroviruses like HIV ?
  1. A.Initiating transcription of viral genes
  2. B.Synthesizing viral DNA from RNA
  3. C.Repairing damaged viral DNA
  4. D.Activating the host's immune response
37
Which process involves the incorporation of foreign DNA into the genome of an organism, resulting in hereditary changes ?
  1. A.Conjugation
  2. B.Transformation
  3. C.Transduction
  4. D.Recombination
38
Which of the following is NOT a step in the lytic cycle of a bacteriophage ?
  1. A.Attachment
  2. B.Replication
  3. C.Integration
  4. D.Assembly
39
What is the primary difference between lytic and lysogenic cycles in bacteriophages ?
  1. A.The lytic cycle results in cell lysis, while the lysogenic cycle integrates into the host genome.
  2. B.The lytic cycle integrates into the host genome, while the lysogenic cycle results in cell lysis.
  3. C.The lytic cycle only occurs in virulent phages, while the lysogenic cycle only occurs in temperate phages.
  4. D.The lytic cycle and lysogenic cycle are identical.
40
In bacterial conjugation, what is the purpose of the fertility (F) plasmid ?
  1. A.It carries antibiotic resistance genes.
  2. B.It promotes the formation of pili.
  3. C.It contains essential genes for bacterial survival.
  4. D.It facilitates the transfer of genetic material between cells.
41
Which type of plasmid is often associated with pathogenic bacteria and carries genes that promote infection and disease ?
  1. A.Resistance plasmid
  2. B.Virulence plasmid
  3. C.Fertility plasmid
  4. D.Fitness plasmid
42
Which of the following is a common method for detecting the presence of plasmids in bacterial cells ?
  1. A.Electron microscopy
  2. B.PCR (Polymerase Chain Reaction)
  3. C.NMR spectroscopy
  4. D.X-ray crystallography
43
Which enzyme is responsible for sealing the gaps in the newly synthesized DNA strand during DNA replication ?
  1. A.DNA polymerase
  2. B.DNA ligase
  3. C.Helicase
  4. D.Topoisomerase
44
In the context of plasmids, what does "low copy number" refer to ?
  1. A.The plasmid can replicate in both the donor and recipient cells.
  2. B.The plasmid is present in a large quantity within the cell.
  3. C.The plasmid is resistant to degradation by restriction enzymes.
  4. D.The plasmid exists in only a few copies per cell.
45
What is the function of reverse transcriptase in retroviruses ?
  1. A.It synthesizes RNA from DNA.
  2. B.It synthesizes DNA from RNA.
  3. C.It cleaves RNA molecules.
  4. D.It replicates the host cell's DNA.
46
In which phase of bacterial growth do cells adapt to the new environment but do not divide ?
  1. A.Lag phase
  2. B.Log phase
  3. C.Stationary phase
  4. D.Death phase
47
Which of the following bacterial structures is involved in the attachment of bacteriophages to the host cell ?
  1. A.Capsule
  2. B.Pili
  3. C.Flagella
  4. D.Ribosomes
48
Which of the following is true regarding the lysogenic cycle of a bacteriophage ?
  1. A.It always leads to the death of the host cell.
  2. B.It involves the integration of the phage DNA into the host chromosome.
  3. C.It results in the immediate lysis of the host cell.
  4. D.It only occurs in virulent phages.
49
What is the primary function of the operator region in bacterial gene regulation ?
  1. A.Initiating transcription
  2. B.Binding to RNA polymerase
  3. C.Regulating the binding of the repressor protein
  4. D.Translating mRNA
50
Which enzyme is responsible for copying DNA into RNA during transcription ?
  1. A.DNA ligase
  2. B.DNA polymerase
  3. C.RNA polymerase
  4. D.Reverse transcriptase