Culture Media MCQs

Q. Which of the statements regarding gram staining is wrong? Mycobacterium tuberculosis stains blue because of the thick lipid layer Streptococcus pyogenes stains blue because of a thick peptidoglycan layer Escherichia coli stains pink because of a thin peptidoglycan layer Mycoplasma pneumoniae is not visible in the Gram’s stain because it has no cell wall […]

Q. Which of the following is not a recognised cause of diarrhoea? Vibrio cholerae Escherichia coli Clostridium perfringens Enterococcus faecalis Answer: Enterococcus faecalis

Q. The prokaryotic cell membrane Contains metabolic enzymes Is selectively permeable Regulates the entry and exit of materials Contains proteins and phospholipids Answer: Contains proteins and phospholipids

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

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

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

Q. Selective media facilitate growth of only one kind of organism. Saboraud medium is used to selectively isolate coliform bacteria gram positive bacteria yeasts acid 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 medium enrichment medium differential medium none of these Answer: differential medium

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

Q. Stuart’s transport medium is used for transport of specimen containing Neisseria gonorrhoeae Salmonella Vibrio cholerae Shigella Answer: Neisseria gonorrhoeae