Question

Assertion: Multicellular organisms are made up of multiple cells instead of one.

Reason: Plasma membrane of a single large cell of the organism would not be able to serve the cytoplasm inside it efficiently.

• A. Both assertion and reason are true and the reason is the correct explanation of the assertion
• B. The assertion is true but reason is false
• C. Both the assertion and reason are false
• D. The assertion is false but the reason is true

Answer 1

The correct option is A Both assertion and reason are true and the reason is the correct explanation of the assertion

Multicellular organisms are made up of multiple cells instead of one large cell. This is so because, as the cell size increases the surface area and the volume increases. But the rate of increase of cytoplasm or volume is much more than the rate of increase of surface area. The size of the cell membrane available to service cytoplasm becomes lesser and lesser. This can result in starving of some inner parts of the cell for the nutrients. Hence, cells divide so that the cell membrane can comfortably service all of the cytoplasm by bringing in nutrients and getting rid of wastes. The cells also divide so that the DNA inside it can efficiently handle the demands placed on it by the cell. Hence, both assertion and reason are true and reason is the correct explanation of the assertion.