Assertion: Some cells enter `G_(0)` phase leading to inactivation of cell cycle.
Reason: `G_(0)` phase occurs due to non-availability of mitogen and energy rich compounds.

Options

A. If both assertion and reason are true and reason is the correct explantion of assertion
B. If both assertion and reason are true but reason is not the correct explnantion of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

A

Explanation

The phase in which cells fail to divide further (do not undergo S-phase after `G_(1)`-phase) is known as `G_(0)` phase or quiescent stage. It occurs due to non-availability of mitogen and energy rich compounds. The cells remain metabolically active, but no longer proliferate unless called on to do so depending on the requirement of the organisms.