Roitt MCQs FINAL TEST 2023.
Which of the following does NOT protect body surfaces:
A Skin
B Mucus
C Gastric acid
D Salivary amylase
E Gut microflora - ANSWER D - Salivary amylase does not protect body surfaces, as enzymes assist in digestion only. All others influence environment.
Pattern recognition receptors (PRR) include:
A LPS.
B PAMPs.
C Lipoteichoic acid.
D Lectin-like molecules.
E Unmethylated CpG sequences. - ANSWER D - PAMP includes Lectin-like molecules. PCR recognises exposed microbial sugars.
The mononuclear phagocyte system does not include:
A Monocytes.
B Kupffer cells.
C Kidney mesangial cells.
D Lymph node medullary macrophages.
E Endothelial cells. - ANSWER E - Endothelial cells, which are not essentially phagocytic although they do contribute by the production of mediators of the inflammatory process, particularly acute inflammation
A polymorphonuclear neutrophil (PMN):
A Is a bone marrow stem cell.
B Is closely similar to a mast cell.
C Contains microbicidal cytoplasmic granules.
D Is not a professional phagocytic cell.
E Has granules which stain with eosin. - ANSWER C - The polymorphonuclear neutrophil (PMN) contains microbicidal cytoplasmic granules, where the granules contain a wide spectrum of microbicidal agents.
Which of the following is not produced following activation of the NADPH oxidase microbicidal pathway:
A O2 -
B O2
C H2O2 D NO
E OH - ANSWER D - Nitrous oxide is produced following the induction of nitric oxide synthase, whereas Oxygen, alcohols and hydrogen peroxide are produced following activation of the N A D P H oxidase microbicidal pathway.
Neutrophil defensins are:
A Anti-toxins.
B Oxygen-dependent.
C Enzymes.
D Glycolipids.
E Peptide antibiotics. - ANSWER E - Neutrophil defensins are peptide antibiotics which present in the granules in extremely high concentrations
The TLR9 pattern recognition receptor recognises:
A CpG motifs.
B Gram +ve peptidoglycan.
C Mycobacterial lipoarabinomannan.
D Gram -ve LPS.
E dsRNA - ANSWER A - Toll-like receptor 9 recognition of CPG motifs, microbial dinucleotide sequences, leads to activation of the NFkB transcription factor
Complement component C3 is cleaved by:
A C3b
B C3bBb
C Factor B
D Factor D
E Factor H - ANSWER B - C3bBb is the C3 convertase enzyme generated in the alternative complement pathway and is responsible for splitting off the small peptide C3a leaving C3b as a residue.
The membrane attack complex consists of:
A OH.
B Colicins
C C3b3b,Bb
D C5b,6,7,8,9
E Properdin - ANSWER D - The membrane attack complex consists of C5b, C6, C7, C8, and C9 - the Cterminal components form a complex which inserts into the membrane to form a transmembrane ion channel which leads to lysis of the cell.
C3b:
A Is chemotactic.
B Is an anaphylatoxin.
Which of the following does NOT protect body surfaces:
A Skin
B Mucus
C Gastric acid
D Salivary amylase
E Gut microflora - ANSWER D - Salivary amylase does not protect body surfaces, as enzymes assist in digestion only. All others influence environment.
Pattern recognition receptors (PRR) include:
A LPS.
B PAMPs.
C Lipoteichoic acid.
D Lectin-like molecules.
E Unmethylated CpG sequences. - ANSWER D - PAMP includes Lectin-like molecules. PCR recognises exposed microbial sugars.
The mononuclear phagocyte system does not include:
A Monocytes.
B Kupffer cells.
C Kidney mesangial cells.
D Lymph node medullary macrophages.
E Endothelial cells. - ANSWER E - Endothelial cells, which are not essentially phagocytic although they do contribute by the production of mediators of the inflammatory process, particularly acute inflammation
A polymorphonuclear neutrophil (PMN):
A Is a bone marrow stem cell.
B Is closely similar to a mast cell.
C Contains microbicidal cytoplasmic granules.
D Is not a professional phagocytic cell.
E Has granules which stain with eosin. - ANSWER C - The polymorphonuclear neutrophil (PMN) contains microbicidal cytoplasmic granules, where the granules contain a wide spectrum of microbicidal agents.
Which of the following is not produced following activation of the NADPH oxidase microbicidal pathway:
A O2 -
B O2
C H2O2 D NO
E OH - ANSWER D - Nitrous oxide is produced following the induction of nitric oxide synthase, whereas Oxygen, alcohols and hydrogen peroxide are produced following activation of the N A D P H oxidase microbicidal pathway.
Neutrophil defensins are:
A Anti-toxins.
B Oxygen-dependent.
C Enzymes.
D Glycolipids.
E Peptide antibiotics. - ANSWER E - Neutrophil defensins are peptide antibiotics which present in the granules in extremely high concentrations
The TLR9 pattern recognition receptor recognises:
A CpG motifs.
B Gram +ve peptidoglycan.
C Mycobacterial lipoarabinomannan.
D Gram -ve LPS.
E dsRNA - ANSWER A - Toll-like receptor 9 recognition of CPG motifs, microbial dinucleotide sequences, leads to activation of the NFkB transcription factor
Complement component C3 is cleaved by:
A C3b
B C3bBb
C Factor B
D Factor D
E Factor H - ANSWER B - C3bBb is the C3 convertase enzyme generated in the alternative complement pathway and is responsible for splitting off the small peptide C3a leaving C3b as a residue.
The membrane attack complex consists of:
A OH.
B Colicins
C C3b3b,Bb
D C5b,6,7,8,9
E Properdin - ANSWER D - The membrane attack complex consists of C5b, C6, C7, C8, and C9 - the Cterminal components form a complex which inserts into the membrane to form a transmembrane ion channel which leads to lysis of the cell.
C3b:
A Is chemotactic.
B Is an anaphylatoxin.
