Question

DNA and histone proteins are synthesized during which of the following phase of the cell cycle?

• A. S Phase
• B. G1 Phase
• C. G2 Phase
• D. None Of These

Answer 1

The correct option is A

S Phase

The correct option is A.

Explanation of the correct option:

1. An array of events, which occurs within a cell as it grows and differentiates is termed a cell cycle.
2. It comprises four phases, that is, the G1 phase, S phase, G2 phase, and M phase.
3. S phase is the synthesis segment of the cell cycle.
4. It is featured with the replication of DNA and synthesis of histone proteins.
5. These proteins further help in the generation of cellular systems like spindle fiber, which eventually assists in cell differentiation.

Explanation of incorrect options:

Option B:

1. In the G1 phase of the cell cycle, the cell increases the volume of both proteins and organelles and grows physically.
2. It is the period in the cell cycle, that is, from the termination of cell division to the initiation of DNA replication.

Option C:

1. The G2 phase of the cell cycle refers to a period of protein synthesis and cell growth that takes place briskly during which the cell prepares itself for mitosis.
2. Mitosis refers to the process by which chromosomes are replicated within a cell and then segregates, giving rise to two similar nuclei in preparation for the division of the cell.

Final answer: The synthesis of DNA and histone proteins takes place during the S phase of the cell cycle.