CELL DIVISION: During the division of cell DNA replication and cell growth takes place.
CELL CYCLE: The sequence of events by which a cell duplicate its genome ,synthesises the other constituents of the cell and eventually divides into two daughter cells is termed as cell cycle.
GENERATION TIME: Period between two successive cell divisions is called generation time.
•Phases of cell cycle:
•1. Interphase
•2. M- phase
•Before entering the phase of division that is M- phase the cell prepare itself for division that phase is called interphase also called resting phase.
•Interphase —- The cell undergoing both cell growth and DNA replication in orderly manner.It constitute 95% of total cell cycle.It further divided into three phases : G₁ phase or first gap phase , S phase or synthesis phase , G₂ phase or second gap phase.
| INTERPHASE | ACTIVITIES HAPPENING | FORMATION OF | IMPORTANT POINT TO REMEMBER |
| G₁ PHASE | Metabolically active phase cell prepare itself for replication | Nucleotide ATP & amino acids are formed.Mitochondria & chloroplast multiply.ER, Golgi body other cell organelles, RNAs , ribosomes, carbohydrates ,proteins ,fats & non histone proteins are synthesised . | No change in DNA content |
| INTERPHASE | ACTIVITIES HAPPENING | FORMATION OF | IMPORTANT POINT TO REMEMBER |
| S PHASE | Synthesis of new DNA strand on existing one, these strands called sister chromatids, | Histone and non histone priteins are synthesized. | One cell enters into S phase it must undergo mitosis. Longest phase |
| G₂ PHASE | Synthesis of RNA & protein continue | Cytoplasmic organelles doubled protein for spindle and asters are synthesized. |
QUIESCENT STAGE :Some cell do not enter G₁ phase after mitosis and start differentiation into specific type of cells Such cells are said to be in Quiescent stage or G₀ PHASE .These cells start division only when required.