Gram Staining

Q.

Is E. Coli a Gram-positive or Gram-negative bacteria?

Q.

What are gram variable bacteria?

Q. Arrange the following steps in correct order as per Gram’s staining technique
1) Treatment with 0.5% Iodine solution
2) Counter staining with safranin
3) Treatment with absolute ethanol
4) Staining heat fixed smear with crystal violet

1. 4, 1, 3, 2
2. 3, 2, 1, 4
3. 3, 1, 2, 4
4. 4, 2, 3, 1

Q. In Gram staining technique, Gram-positive bacteria

1. appear violet even after the addition of counterstain
2. do not get stained by crystal violet
3. take up the counterstain and appear orange-red
4. lose crystal violet stain on washing with alcohol.

Q.

Which Bacteria Cannot Be Gram Stained?

Q.

Name the bacterium responsible for large holes in swiss cheese.

Q. The dyes that are used in Gram's staining are

1. Crystal violet and methylene blue
2. Crystal violet and safranin
3. Safranin and methylene blue
4. Crystal violet and carbol fuchsin

Q.

Which of the following is a gram negative bacterium?

1. Escherichia coli

2. Streptomyces coelicolor

3. Bacillus subtilis

4. Ampycolatopsis orientalis

Q. Which statement is NOT true about bacteria?

1. Their cell wall is made of a slime layer that is the same as in plant cell walls.
2. Some are photosynthetic.
3. Some are motile due to flagella.
4. They are all prokaryotes.

Q.

How do I differentiate gram positive and gram negative Bacteria?

Q. Gram' staining is a common technique used to differentiate two large groups of bacteria based on their different

1. Cell membrane
2. Extracellular matrix
3. Cell wall
4. All of the above

Q. Give the difference between cell walls of Gram-positive and Gram-negative bacteria.

Q. Which of the following statements is/are correct about heat shock.

1. A step of the process that enables introduction of alien DNA into the host cells
2. Both A and C
3. A step of the process that enables linking of alien DNA to the plasmid
4. Given at 42°C

Q. Short / Long answer type questions.
Distinguish between: Gram negative bacteria and Gram positive bacteria.

Q.

How does peptidoglycan affect Gram staining?

Q. Short / Long answer type questions.
In terms of cell wall structure and composition, explain the difference between Gram -ve and Gram +ve bacteria.

Q. Explain Gram positive and Gram negative

Q. Identify the bacterium that appears violet during Gram staining.

1. Mycobacterium tuberculosis
2. Escherichia coli
3. Rhizobium meliloti
4. Salmonella enterica

Q.

What types of bacteria are gram-positive?

Q. Gram-positive bacteria differ from Gram-negative bacteria in the structure of their

1. Nucleoid / genophore
   
2. Cytoplasm
3. Cell wall
4. Ribosomes

Q. What are Gram-Positive bacteria?

Q. The main difference between Gram positive and Gram negative bacteria is

1. Cell membrane
2. Cell wall
3. Ribosome
4. Mitochondria

Q. Assertion :Gram-negative bacteria do not retain the stain, when washed with alcohol. Reason: The outer face of the outer membrane of Gram-negative bacteria contains lipopolysaccharides, a part of which is integrated into the membrane lipids.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
3. Assertion is correct but Reason is incorrect.
4. Both Assertion and Reason are incorrect.

Q.

What does gram negative bacteria mean?

Q. Find the correct match for the breaking of the cell wall during isolation of genetic material in rDNA procedure.

1. Chitinase - Bacteria
2. All of the above
3. Cellulase - Plant cell
4. Lysozyme - Fungus

Q. Gram-negative bacteria that cause infections, when stained, do not retain the crystal violet stain, which tells the researcher that

1. The peptidoglycan layer is very thin and the bacteria is susceptible to antibiotics.
2. The peptidoglycan layer is very thin and the bacteria are resistant to antibiotics.
3. The peptidoglycan layer contains an impermeable lipid layer.
4. The peptidoglycan layer is thick and the bacteria are resistant to antibiotics.

Q. Pick up incorrect statement about bacterial capsule.

1. Capsular material is antigenic in nature.
2. It protects bacteria by inhibiting phagocytosis.
3. It cannot be stained by Gram's stain.
4. It is acid fast in nature.

Q.

Which of the following bacterium is associated with the roots of legumes?

1. Rhizobium

2. Nostoc

3. Spirogyra

4. Clostridium

Q. Bacteria which retain purple colour after staining with gram stain is

1. Trichous
2. Gram -ve
3. Spirillum
4. Gram +ve

Q. Difference in Gram +ve and Gram -ve bacteria is due to

1. Cell wall
2. Cell membrane
3. Ribosome
4. Cytoplasm