The amount of DNA is same in G1 or growth 1 phase and G0 stage or Quiescent phase. In G0 stage the cell is neither dividing nor preparing to divide. In the G1 stage, only growth takes place no replication of DNA takes place. So, the amount of DNA remains the same in G1 and G0 stage.

G 1 phase is also known as first growth phase or post mitotic gap phase. It is the phase between end of mitotic phase of previous cell and initiation of S-phase of next mitotic phase. During G 1 phase the cells is metabolically active and continuously grows. In this phase different type of RNA (mRNA,tRNA and rRNA) and proteins are synthesised.

Sol: The correct answer is option “B”. G1 phase is usually the longest phase of cell cycle. G1 phase is the first gap phase where the cell is preparing for the other stages of cell cycle. Moreover, G1 phase follows the mitosis cell division. It is the time for the newly formed cells to grow before the DNA replication. So, the G1 phase is ...

Interphase is the resting phase between two successive mitotic divisions of a cell, at G1 phase the chromosomes will remain 7, at S phase chromosomes become double i.e. 14 and at M phase it remains same.

The cell cycle is the series of events that lead to the doubling of DNA of a cell and the formation of two daughter cells. It is divided into four phases- G1, S, G2, and M phase. In the S phase DNA content is doubled.

During G1- phase, cells grow and synthesize the 20 amino acids needed to manufacture proteins later on. B. Cell cycle begins with the resting phase. During this phase, cells are at ''rest''.

The interphase of a typical cell cycle comprises of G1 phase, S phase and G2 phase. The S phase stands for synthesis phase in which DNA replication occurs followed by synthesis of histones. This is the phase occurring between G 1 and G 2 phase.

B. G1 phase is the interval between mitosis and initiation of DNA replication. In this, the cell does not synthesize or replicate DNA but remains metabolically active. C. G2 phase is the second gap phase present between S and M phase.

It is given that the number of chromosomes present in each onion root tip cell is 16. Hence, the number of chromosomes in the cell will be 16 at G 1 phase, after S phase and after M phase. Also, if the DNA content after M phase is 2C. Hence, the DNA content at G 1 phase will be 2C. It will be 4C after S and G 2 phase.

G1 phase together with the S phase and G 2 phase comprise the long growth period of the cell cycle cell division called interphase that takes place before cell division in mitosis (M phase). During G 1 phase, the cell grows in size and synthesizes mRNA and protein that are required for DNA synthesis. So, the correct option is D.