Question

In the given figure, mitosis is represented by which number?

• A. I
• B. II
• C. III
• D. IV
• E. V

Answer 1

The correct option is D IV


The given figure is a representation of the amount DNA found in a eukaryotic cell over two complete cell cycle.
A eukaryotic cell cycle consists of four stages, namely, G1 phase, S phase, G2 phase and M phase.
- The G₁ phase or Gap 1 phase, is part of interphase, during which the cell synthesizes mRNA and proteins in preparation for subsequent steps leading to mitosis.
- The S phase or synthesis phase is the part of the cell cycle in which DNA is replicated and occurs between G₁ phase and G₂ phase.
- The G₂ phase or Gap 2 phase immediately follows the S phase, during which the cell checks the DNA for any damage that might have occurred during replication and ensures all the proteins necessary for cell division are present.
- The M phase or mitotic phase of a eukaryotic cell cycle is the phase in which the mother cell divides into two daughter cells that are genetically identical to each other.
Therefore, in the given figure,
- I is the G1 phase
- II is the S phase, as DNA gets replicated during this phase and the cell ends up with double the amount of DNA.
- III is the G2 phase
- IV is the M phase, as the cell divides and the DNA is shared equally among the daughter cells.
- V is the G1 phase of the following cell cycle.