Question

Gram negative bacteria do not retain the stain when washed with alcohol. The outer membrane of Gram negative$(-ve)$ bacteria contain lipopolysaccharides, a part of which is integrated into membrane lipid.

• A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
• B. Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
• C. Assertion is true, but Reason is false.
• D. Both Assertion and Reason are false.

Answer 1

Answer: (A)

Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Answer 2

Gram staining bacteria technique was developed by Hans Christian Gram (a Danish Bacteriologist) in $1884.$ On the basis of technique, bacteria can be classified into (a) Gram positive; show positive test with Gram stain. (b) Gram negative; show negative test with Gram stain. The step involve in gram staining are summarised as The composition of bacterial cell wall is basis for Gram staining technique. The cell wall of Gram $( - ve)$ bacteria contain alcohol soluble lipid (lipopolysaccharides) while the cell wall of $(+ ve)$ Gram positive bacteria lack these lipid there retain crystal violet iodine complex used.