L1 intro to Microbiology

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What happens when microorganisms are introduced directly into the bloodstream or internal organs?

The microorganisms multiply and cause the host to react, leading to infection. (correct)

The host's body functions are impaired, leading to infectious disease.

The host's immune system immediately eliminates the microorganisms.

The microorganisms enter a carrier state, but do not cause harm to the host.

What is the characteristic of the chromosome in prokaryotic cells?

Single, circular chromosome with nucleoli (correct)

Single, linear chromosome with no nucleoli

Multiple, linear chromosomes with nucleoli

Multiple, circular chromosomes with no nucleoli

What is a characteristic that distinguishes eukaryotic pathogens from others?

Ability to undergo photosynthesis

Ability to form endospores

Absence of a cell wall

Presence of a well-defined nucleus (correct)

What is the function of the cell wall in bacteria?

To maintain a fixed cell shape Signup and view all the answers

What is the main difference between prokaryotic and eukaryotic cells?

Presence or absence of a nucleus Signup and view all the answers

Which of the following is NOT a characteristic of bacteria?

Presence of a well-defined nucleus Signup and view all the answers

What is a characteristic of mycoplasma?

Lack of a cell wall Signup and view all the answers

What is the common characteristic of prokaryotic pathogens?

They are mainly divided into bacteria and archaea Signup and view all the answers

Which of the following is an example of an atypical bacterium?

Chlamydia Signup and view all the answers

What is the name of the basic shape that bacteria can assume?

Coccus, bacillus, or vibrio Signup and view all the answers

What is the characteristic of helminths?

Multicellular, eukaryotic, and parasitic Signup and view all the answers

What is the characteristic of the ribosome in prokaryotic cells?

70S Signup and view all the answers

What is the size range of prokaryotic cells?

0.2-2 mm in diameter Signup and view all the answers

What is the composition of viruses?

Genetic material surrounded by a protein coat Signup and view all the answers

What is the characteristic of prions?

Altered protein conformation and point mutations Signup and view all the answers

Which of the following is NOT a characteristic of protozoa?

Photosynthetic Signup and view all the answers

What is the primary mechanism by which normal flora prevent the colonization of the body by pathogens?

Production of antimicrobial substances Signup and view all the answers

What is the function of the capsule in bacterial cells?

To mediate adherence to surfaces Signup and view all the answers

What is the composition of the cell cytoplasmic membrane in bacteria?

Phospholipid bilayer Signup and view all the answers

What is the function of Vit.K and Vitamin B produced by normal flora?

To aid in digestion and nutrient absorption Signup and view all the answers

What is the effect of C.di on the gut?

Irritation Signup and view all the answers

What is the significance of bacterial colonization in new-born infants?

Stimulates immune response Signup and view all the answers

What is the characteristic feature of all bacteria?

Prokaryotic cell structure Signup and view all the answers

What is the difference between Gram-positive and Gram-negative bacteria?

Thickness of the peptidoglycan layer Signup and view all the answers

What is the primary function of the self-produced matrix of extracellular polymeric substances in biofilm formation?

To protect the bacteria from the host's immune response and antimicrobial drugs Signup and view all the answers

Which of the following is an example of host-mediated pathogenesis?

Inflammation caused by the host's immune response Signup and view all the answers

What is the primary purpose of antigenic variation in bacteria?

To evade the host's immune system Signup and view all the answers

Which structure is used by Escherichia coli to adhere to host cells?

Pili Signup and view all the answers

What is the primary function of bacterial enzymes such as collagenase and hyaluronidase?

To degrade the host's extracellular matrix Signup and view all the answers

What is the term for the ability of bacteria to enter or penetrate host cells or mucosa?

Invasiveness Signup and view all the answers

What is the name of the membrane protein that interacts with host cells to facilitate bacterial uptake?

Invasion Signup and view all the answers

Which of the following is NOT a mechanism used by bacteria to evade the host's immune system?

Production of toxins that harm the host Signup and view all the answers

What is the primary characteristic of exotoxins produced by bacteria?

They are secreted out of the pathogenic cell and are highly toxic Signup and view all the answers

Which type of toxin is a lipid portion of lipopolysaccharide (LPS) that is part of the outer membrane of Gram-negative bacteria?

Endotoxin Signup and view all the answers

What is the primary difference between aerobic and anaerobic respiration in bacteria?

The type of electron acceptor used Signup and view all the answers

What is the purpose of Gram staining in the identification of bacteria?

To distinguish between Gram-positive and Gram-negative bacteria Signup and view all the answers

Which of the following is a characteristic of Gram-positive bacteria?

A thick layer of peptidoglycan in the cell wall Signup and view all the answers

What is the primary advantage of aerobic respiration over fermentation in bacteria?

It produces more ATP Signup and view all the answers

Which of the following is a characteristic of endotoxins?

They are moderately toxic and heat stable Signup and view all the answers

What is the primary difference between obligate and facultative anaerobes?

Their ability to use oxygen as a terminal electron acceptor Signup and view all the answers

What is the primary function of the electron transport chain in bacterial energy production?

To produce ATP Signup and view all the answers