In this stage, rapid bio-synthesis occurs, due to which the size of the cell doubles. This stage is called. resting stage but it is the most active stage of the cell cycle. Interphase is also called preparatory phase. In this stage the following events occur :
(i) Due to synthesis of various substances, the size of nucleus and cytoplasm increases.
(ii) Two daughter centrosomes are formed by division of the centrosome.
(iii) Due to replication in DNA, the quantity doubles.
(iv) Energy containing compounds (ATP) are synthesised.
This stage has been divided into the following three periods:
1. G
1 state, 2. S state, 3. G
2 state.