Microbiology FINAL Review (Jersey
College) Questions and Answers | Latest
Update | 2024/2025 | 100% Verified
What is the primary function of the bacterial cell wall?
✔✔The bacterial cell wall provides structural support and protection to the cell, maintaining its
shape and preventing osmotic lysis.
Describe the role of plasmids in bacterial cells.
✔✔Plasmids are small, circular DNA molecules that replicate independently of the chromosomal
DNA, often carrying genes that confer advantageous traits like antibiotic resistance.
What is the difference between Gram-positive and Gram-negative bacteria in terms of cell wall
structure?
✔✔Gram-positive bacteria have a thick peptidoglycan layer in their cell wall, while Gram-
negative bacteria have a thin peptidoglycan layer and an outer membrane containing
lipopolysaccharides.
1
,Explain the process of bacterial conjugation.
✔✔Bacterial conjugation is a horizontal gene transfer method where one bacterium transfers
genetic material to another through a direct connection known as a pilus.
What is the function of the ribosome in a bacterial cell?
✔✔Ribosomes in bacterial cells are responsible for protein synthesis by translating mRNA into
polypeptide chains.
Describe the role of the lysogenic cycle in bacteriophage infections.
✔✔In the lysogenic cycle, a bacteriophage integrates its DNA into the host bacterium’s genome,
replicating with it until environmental triggers induce the lytic cycle, leading to cell lysis.
What is an endospore and its function in bacterial survival?
2
,✔✔An endospore is a dormant, highly resistant structure formed by some bacteria to withstand
extreme environmental conditions, such as heat and dehydration, ensuring survival.
How do antibiotics like penicillin target bacterial cells?
✔✔Penicillin targets bacterial cells by inhibiting the synthesis of peptidoglycan, a critical
component of the bacterial cell wall, leading to cell lysis and death.
Explain the significance of the Koch's postulates in microbiology.
✔✔Koch's postulates are a set of criteria used to establish a causative relationship between a
microbe and a disease, involving isolating the pathogen, reproducing the disease, and re-isolating
the pathogen.
What is the role of the microbial flora in human health?
✔✔The microbial flora helps maintain a balanced ecosystem in the human body, aids in
digestion, competes with pathogenic microbes, and supports the immune system.
3
, What is the purpose of a bacterial capsule?
✔✔A bacterial capsule provides an additional layer of protection against phagocytosis by
immune cells and can enhance the bacterium's virulence.
Describe the function of the bacterial flagellum.
✔✔The bacterial flagellum is a whip-like structure that enables motility by rotating and
propelling the bacterium through its environment.
What is the role of the bacteriophage in horizontal gene transfer?
✔✔Bacteriophages can facilitate horizontal gene transfer by transferring genetic material
between bacteria during their replication cycles, a process known as transduction.
Explain the difference between exotoxins and endotoxins.
✔✔Exotoxins are toxic proteins secreted by bacteria that can cause damage to host cells, while
endotoxins are components of the Gram-negative bacterial cell wall released upon cell lysis.
4
College) Questions and Answers | Latest
Update | 2024/2025 | 100% Verified
What is the primary function of the bacterial cell wall?
✔✔The bacterial cell wall provides structural support and protection to the cell, maintaining its
shape and preventing osmotic lysis.
Describe the role of plasmids in bacterial cells.
✔✔Plasmids are small, circular DNA molecules that replicate independently of the chromosomal
DNA, often carrying genes that confer advantageous traits like antibiotic resistance.
What is the difference between Gram-positive and Gram-negative bacteria in terms of cell wall
structure?
✔✔Gram-positive bacteria have a thick peptidoglycan layer in their cell wall, while Gram-
negative bacteria have a thin peptidoglycan layer and an outer membrane containing
lipopolysaccharides.
1
,Explain the process of bacterial conjugation.
✔✔Bacterial conjugation is a horizontal gene transfer method where one bacterium transfers
genetic material to another through a direct connection known as a pilus.
What is the function of the ribosome in a bacterial cell?
✔✔Ribosomes in bacterial cells are responsible for protein synthesis by translating mRNA into
polypeptide chains.
Describe the role of the lysogenic cycle in bacteriophage infections.
✔✔In the lysogenic cycle, a bacteriophage integrates its DNA into the host bacterium’s genome,
replicating with it until environmental triggers induce the lytic cycle, leading to cell lysis.
What is an endospore and its function in bacterial survival?
2
,✔✔An endospore is a dormant, highly resistant structure formed by some bacteria to withstand
extreme environmental conditions, such as heat and dehydration, ensuring survival.
How do antibiotics like penicillin target bacterial cells?
✔✔Penicillin targets bacterial cells by inhibiting the synthesis of peptidoglycan, a critical
component of the bacterial cell wall, leading to cell lysis and death.
Explain the significance of the Koch's postulates in microbiology.
✔✔Koch's postulates are a set of criteria used to establish a causative relationship between a
microbe and a disease, involving isolating the pathogen, reproducing the disease, and re-isolating
the pathogen.
What is the role of the microbial flora in human health?
✔✔The microbial flora helps maintain a balanced ecosystem in the human body, aids in
digestion, competes with pathogenic microbes, and supports the immune system.
3
, What is the purpose of a bacterial capsule?
✔✔A bacterial capsule provides an additional layer of protection against phagocytosis by
immune cells and can enhance the bacterium's virulence.
Describe the function of the bacterial flagellum.
✔✔The bacterial flagellum is a whip-like structure that enables motility by rotating and
propelling the bacterium through its environment.
What is the role of the bacteriophage in horizontal gene transfer?
✔✔Bacteriophages can facilitate horizontal gene transfer by transferring genetic material
between bacteria during their replication cycles, a process known as transduction.
Explain the difference between exotoxins and endotoxins.
✔✔Exotoxins are toxic proteins secreted by bacteria that can cause damage to host cells, while
endotoxins are components of the Gram-negative bacterial cell wall released upon cell lysis.
4
