Question

The correct sequence in cell cycle is

(a) S - M - G₁ - G₂ 

(b) S - G₁ - G₂ - M

(c) G₁ - S - G₂ - M 

(d) M - G₁ - G₂ - S

Answer 1

The correct option is: (c) G₁ - S - G₂ - M 

Explanation:

The orderly sequence of events by which the cell duplicates its contents and then divides into two is termed as cell cycle. The cell cycle comprises of two periods: interphase (I phase) and mitotic phase (M-phase). 

Cell however, spends most of its life span in interphase. Interphase is a period of intense biosynthetic activity. It can be divided into three periods. 

(i) Post-mitotic gap phase (G₁) 

(ii) Synthetic phase (S) 

(iii) Pre mitotic gap phase (G₂) 

The sequence of cell cycle is G₁ → S → G₂ → M. 

RNA and protein synthesis take place during G₁and G₂ phase. DNA synthesis takes place during S phase.