Question

Which is the shortest phase in the cell cycle?
A) G-1
B) G-2
C) S
D) M

Answer 1

Hint: Generally, the life of a cell begins with its formation by cell division of a mother cell and the life ends of the cell with either the formation of daughter cells or with its death. The stages through which a cell passes from cell division to the formation of its daughter cells, constitutes the cell cycle.

Complete solution:
Let us evaluate the options given for the question.
1) First option is the G-1 phase.
 G-1 phase is also known as post mitotic gap phase. It is typically the longest phase of the interphase and interface is the longest phase of cell cycle so ultimately G-1 is the longest phase of cell cycle. The decision for the cell division occurs in this phase, the cell would normally proceed to mitosis without any interruption when it has entered the S phase. If the decision is not in the favor of division then the cell enters a quiescent stage.
2) The second option is the G-2 phase.
It is also known as pre mitotic gap phase. This phase is actually the period between the end of the S phase and the start of the mitosis. During this period the final preparation for the cell division occurs. The final preparations include the repair of damaged DNA, synthesis of tubulin for the spindle Apparatus and ATP accumulation for the energy expensive mitosis.
3) The next option is S phase.
This is the synthesis phase. It is that specific part of the interface during which the DNA synthesis and histone synthesis occurs. In this stage, the centrioles often self duplicate themselves.
G-1, G-2 and S phase are the parts of Interphase of the cell division.
4) The next option is M phase.
M phase is the typical phase of cell division where cell division occurs in various steps. This phase is also known as mitotic phase.
When we assume for rapidly dividing a human cell with the total cycle of 24 hours, G-1 phase might last for about 11 hours, S phase last for about 7 hours, G-2 for about four hours and the last M phase is of about 2 hours only.
From the above time division, it is very clear that the M phase is the shortest phase of cell division or cell cycle.

In concern to the above question, The correct answer is option D.

Note: The shortest phase of the cell cycle is the Mitotic phase (M phase) and the longest phase of the cell cycle is G-1 phase.