Gram stain

Question 1

gram staining is an example of which type of staining?

Answer 1

differential stain

Question 2

what is the primary stain used in Gram staining?

Answer 2

crystal violet

Question 3

what is the function of iodine in Gram staining?

Answer 3

mordant

Question 4

which type of bacteria retains the crystal violet stain after alcohol treatment?

Answer 4

gram-positive

Question 5

gram-positive bacteria have a thick layer of which component in their cell wall?

Answer 5

peptidoglycan

Question 6

gram-negative bacteria have an outer membrane rich in which component?

Answer 6

Lipopolysaccharide

Question 7

what color do gram-negative bacteria appear after gram staining?

Answer 7

pink

Question 8

which of the following is a common gram-positive bacterium?
- E. coli
- Lactobacillus
- salmonella
- pseudomonas

Answer 8

Lactobacillus

Question 9

which of the following is a common Gram-negative bacterium?
- Staph. aureus
- Bacillus subtilis
- E. coli
- Clostridium

Answer 9

E. Coli

Question 10

why do gram-negative bacteria lose the crystal violet stain?
- thin peptidoglycan layer
- high lipid content in the outer membrane
- presence of teichoic acids
- both a and b

Answer 10

both a and b