Q. Which of the statements regarding gram staining is wrong? Mycobacterium tuberculosis stains blue because of the thick lipid layerStreptococcus pyogenes stains blue because of a thick peptidoglycan layerEscherichia coli stains pink because of a thin peptidoglycan layerMycoplasma pneumoniae is ...

Q. Which of the following is not a recognised cause of diarrhoea? Vibrio choleraeEscherichia coliClostridium perfringensEnterococcus faecalis Answer: Enterococcus faecalis

Q. The prokaryotic cell membrane Contains metabolic enzymesIs selectively permeableRegulates the entry and exit of materialsContains proteins and phospholipids Answer: Contains proteins and phospholipids

Q. Which of these bacterial components is least likely to contain useful antigens? Cell wallFlagellaRibosomesCapsule Answer: Ribosomes

Q. Which of the following contains structures composed of N-acetylmuramic acid and N- acetylglucosamine? MycoplasmasAmoebaE.coliSpheroplast Answer: E.coli

Q. The association of endotoxin in gram-negative bacteria is due to the presence of SteroidsPeptidoglycanLipopolysaccharidesPolypeptide Answer: Lipopolysaccharides

Q. Selective media facilitate growth of only one kind of organism. Saboraud medium is used to selectively isolate coliform bacteriagram positive bacteriayeastsacid fast organisms Answer: yeasts

Q. The medium which allows the growth of more than one microorganisms of interest but with morphologically distinguishable colonies is known as selective mediumenrichment mediumdifferential mediumnone of these Answer: differential medium

Q. Plate counts are often reported as cfucfu/mlBoth (a) and (b)thousands/ml Answer: cfu/ml

Q. Stuart’s transport medium is used for transport of specimen containing Neisseria gonorrhoeaeSalmonellaVibrio choleraeShigella Answer: Neisseria gonorrhoeae