Question 1

All of the following are true as regard endospore except:
A) Can be stained by gram stain
B) Highly resistant
C) Formed outside host
D) Formed in adverse conditions

Accepted Answer

Endospores are not stained by Gram stain.

Question 2

Which of the following statmenets about virus induced cytopathic changes is most accurate:
A) They are pathognomonic for an infecting virus
B) They are rarely associated with cell death
C) They may include giant cell formation
D) They can only be seen by an electron microscope

Accepted Answer

Cytopathic changes can include giant cell formation, which is a common effect of viral infections on cells.

Question 3

Which of the following can be used to quantitate the titer of infectious viruses:
A) Plaque assay
B) Electron microscopy
C) Hemagglutination
D) PCR
E) Enzyme immunoassay

Accepted Answer

A plaque assay is used to quantitate the titer of infectious viruses by measuring the number of plaques formed on a cell monolayer, each representing an infectious virus particle.

Question 4

Which of the following statements regarding virus morphology is true:
A) All RNA viruses are spherical in shape
B) Some viruses contain flagella
C) Some viruses with DNA genome contain nucleus
D) Viral surface proteins protect viral genome from nucleases
E) Helical nucleocapsid are found with single stranded DNA virus

Accepted Answer

Viral surface proteins can play a role in protecting the viral genome from nucleases by forming a protective capsid or envelope around the nucleic acid.

Question 5

Prion is an atypical virus that contain which of the following:
A) Circular RNA
B) Multiple copies of plasmid
C) No detectable nucleic acid
D) Double stranded RNA
E) Host cell DNA instead of viral DNA

Accepted Answer

Prions are infectious agents composed entirely of protein, with no detectable nucleic acid, distinguishing them from viruses which typically contain RNA or DNA.

Question 6

Which of the following statements best describe virus:
A) Obligatory extracellular parasites
B) Can be grown on blood agar
C) Contain both DNA and RNA
D) Can be treated by antibiotics
E) Very small in size $ 20.300 \mathrm{~nm} $

Accepted Answer

Viruses are very small, typically ranging from 20 to 300 nm in size. They are not obligatory extracellular parasites, cannot be grown on blood agar, do not contain both DNA and RNA (only one type), and cannot be treated with antibiotics.

Question 7

Viral replication:
A) Occurs by binary fission
B) Requires host cell macromolecules
C) Can be prevented by antibiotics
D) Can occur in synthetic media

Accepted Answer

Viral replication requires host cell macromolecules because viruses lack the necessary machinery for replication and must hijack the host cell's machinery to reproduce.

Question 8

Capsid symmetry found in smallpox VIRUS IS:
A) Helical
B) Complex
C) Icosahedral
D) Non Of These

Accepted Answer

The smallpox virus, which is a member of the Poxviridae family, has a complex capsid symmetry, unlike the more common helical or icosahedral symmetries found in many other viruses.

Question 9

One of the following statements is not true for viruses:
A) Contain either DNA of RNA
B) Lack mitochondria
C) Contain protein coat
D) Multiply by binary fission

Accepted Answer

Viruses do not multiply by binary fission; they replicate by hijacking the host cell's machinery to produce new virus particles.

Question 10

Which statement regarding fungi is correct :
A) All fungi are able to grow as yeast and mold
B) Although fungi are eukaryotes they lack mit. ' dria
C) Fungi are photosynthetic
D) Fungi have nucleus and chromosomes
E) Few ungi possess cell membranes

Accepted Answer

Fungi are eukaryotic organisms, meaning they have a defined nucleus and chromosomes within their cells.

Question 11

Toxoid is :
A) Toxin lost its antigenicity but not toxicity
B) Toxin lost its toxicity but still antigenic
C) Toxin lost toxicity and antigenicity
D) Non of the above

Accepted Answer

A toxoid is a toxin that has been inactivated so that it is no longer toxic but still retains its antigenic properties, allowing it to stimulate an immune response.

Question 12

Endotoxins:
A) Mucopolysaccharides
B) Lipopolysaccharides
C) Nucleic acid
D) Proteins
E) Peptidoglvcan

Accepted Answer

Endotoxins are lipopolysaccharides found in the outer membrane of Gram-negative bacteria.

Question 13

Carriers are dangerous source of infection more than cases because:
A) They have no clinical symptoms
B) Never shed the organism outside their bodies
C) The isolated organism is more virulent
D) All of the above

Accepted Answer

Carriers are dangerous because they can spread the infection without showing any symptoms, making it harder to identify and control the source of infection.

Question 14

Exotoxins:
A) Lipoproteins
B) LPS
C) Nucleic acid
D) Proteins
E) Peptidoglvcan

Accepted Answer

Exotoxins are toxic substances secreted by bacteria and are typically composed of proteins.

Question 15

Which one of the following best describes the mode of action of endotoxins:
A) Drgrades lecithin in cell membrane
B) Hypertension
C) Block release of acetyl choline
D) Causes the release of tumor necrosis factor

Accepted Answer

Endotoxins, particularly lipopolysaccharides from Gram-negative bacteria, stimulate immune cells to release cytokines like tumor necrosis factor (TNF), leading to inflammation and other systemic effects.

Question 16

Enzyme which can destroy neutrophils and macrophages:
A) Leukocidins
B) IgA protease
C) Coagulase
D) Collagenase

Accepted Answer

Leukocidins are enzymes produced by certain bacteria that can destroy white blood cells, including neutrophils and macrophages, by creating pores in their cell membranes.

Question 17

The organism continue to grow with or without producing symptoms
A) Acute infection
B) Latent infection
C) 2 ry infection
D) Chronic infection

Accepted Answer

Chronic infections are characterized by the continuous presence of the organism, which may or may not produce symptoms over time.

Question 18

The time from initial contacts with the infectious agents to the appearance of the $ 1^{14} $ symptoms:
A) Prodromal stage
B) Invasion stage
C) Incubation period
D) Convalescent period

Accepted Answer

The incubation period is the time between exposure to an infectious agent and the appearance of the first symptoms.

Question 19

The ability of the organism to cause disease:
A) Infectious dose
B) Pathogenicity
C) Virulence
D) Infection

Accepted Answer

Pathogenicity refers to the ability of an organism to cause disease.

Question 20

Infectious dose of shigella is:
A) 10
B) 100
C) 100000
D) 1000000

Accepted Answer

The answer of Infectious dose of shigella is:
A) 10
B) 100
C)...

Quiz 1: Pathogenesis-Antibiotic-Structure

All of the following are true as regard endospore except:

Which of the following statmenets about virus induced cytopathic changes is most accurate:

Which of the following can be used to quantitate the titer of infectious viruses:

Which of the following statements regarding virus morphology is true:

Prion is an atypical virus that contain which of the following:

Which of the following statements best describe virus:

Viral replication:

Capsid symmetry found in smallpox VIRUS IS:

One of the following statements is not true for viruses:

Which statement regarding fungi is correct :

Toxoid is :

Endotoxins:

Carriers are dangerous source of infection more than cases because:

Exotoxins:

Which one of the following best describes the mode of action of endotoxins:

Enzyme which can destroy neutrophils and macrophages:

The organism continue to grow with or without producing symptoms

The time from initial contacts with the infectious agents to the appearance of the $1^{14}$ symptoms:

The ability of the organism to cause disease:

Infectious dose of shigella is: