Question

The M phase of the cell cycle consist of
A. G1, S, and G2 phase
B. Prophase, metaphase, anaphase, telophase
C. Interphase, prophase, metaphase, anaphase, telophase
D. Only prophase

Answer 1

Hint: The cell division takes place in two stages – interphase and M phase or mitotic phase. Interphase is the preparation phase and the M phase of a cell cycle is the cell division phase.

Complete answer:The interphase of the cell cycle is divided into three stages – G1, S, and G2 phase.
1. In the G1 phase of the cell cycle cell growth occurs.
2. In the S phase of the synthetic phase DNA replication takes place.
3. In the G2 phase final cell growth takes place.
4. The interphase takes almost 20-22 hours for the preparation of cell division.
5. In the G1 phase, there is a G0 phase – where the cell takes rest.
It is an inactive phase.
Neurons of the human body are in the G0 phase.
So, it cannot divide.
The mitotic phase consists of four phases – prophase, metaphase, anaphase, and telophase.

In prophase the nuclear membrane and nucleolus disappear, the condensation of chromatin takes place. Centriole comes near to the nucleus for the onset of cell division.
In metaphase, the centrioles form astral rays and spindle fibres.
The chromosomes form chromatids and are attached to the spindle and placed equatorially in the center of the cell.
In the anaphase, the anaphasic movement takes place where the chromatids separate from each other and move to the opposite poles.
In the final stage of cell division that is in telophase, the cleavage from the equatorial position starts as well as cytokinesis starts and the cell divides into two halves. In the case of plant cells, a cell plate forms in the telophase at the equatorial region by deposition of cellulose.

So, the correct answer is option B. Prophase, metaphase, anaphase, telophase.

Note: Cell division has three functions –
1. Reproduction of unicellular organisms
2. The production of gametes and
3. Growth in eukaryotes.
Cell division is of two types – mitosis and meiosis.
Mitosis takes place in somatic cells whereas meiosis takes place in gametic cells.