Question

Assertion : A cell membrane shows fluid-mosaic behaviour.
Reason : A membrane is composed of lipids and proteins.

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

Answer 1

The correct option is A

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

Option (a):

Assertion statement:

1. Cell membrane shows fluid mosaic behaviour.
2. It is a thin semi permeable membrane layer, which surrounds the cytoplasm and other constituents of the cell.

Reason statement:

1. Cell membrane is composed of two layers of phospholipids and embedded with proteins.

Final answer: (a) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.