Which activity takes place during post - mitotic gap phase (G1) ?
RNA and protein synthesis
Understanding the Post-Mitotic Gap Phase (G1)
The cell cycle is a series of events that takes place in a cell as it grows and divides. It consists of four main phases: G1 (Gap 1), S (Synthesis), G2 (Gap 2), and M (Mitotic phase).
Activities in the G1 Phase
The G1 phase, also known as the first gap phase or post-mitotic gap phase, is a period of cell growth and preparation for DNA synthesis. It is typically the longest phase of the cell cycle. During the G1 phase, the cell is metabolically active and carries out the following key activities:
- Intensive synthesis of RNA (ribonucleic acid).
- Synthesis of proteins and enzymes necessary for DNA replication and cell growth.
- Accumulation of energy reserves.
- Increase in cell size.
This phase is crucial because the cell grows and synthesizes the necessary components and machinery before it commits to replicating its DNA.
Analyzing the Options
Let's look at the given options in the context of the cell cycle phases:
- RNA and protein synthesis: As discussed, extensive RNA and protein synthesis is a primary activity during the G1 phase, preparing the cell for subsequent DNA replication and division.
- DNA synthesis: DNA synthesis, or replication, occurs specifically during the S phase of the cell cycle, not the G1 phase.
- Continuation of RNA and protein synthesis: While RNA and protein synthesis continue in the G2 phase as well, the G1 phase is characterized by significant synthesis aimed at growth and preparing for DNA replication. Option 1 is a more precise description of a major activity initiating in G1.
- More than one of the above: Based on the analysis, only the first option accurately describes a key activity predominantly occurring in the G1 phase.
- None of the above: The first option correctly describes a G1 activity.
Therefore, the activity that prominently takes place during the post-mitotic gap phase (G1) is RNA and protein synthesis.
Summary of Cell Cycle Phases and Activities
| Phase | Key Activities |
|---|---|
| G1 Phase (Post-mitotic gap) | Cell growth, synthesis of RNA, proteins, and enzymes; preparation for DNA synthesis. |
| S Phase (Synthesis) | DNA replication occurs; each chromosome becomes duplicated. |
| G2 Phase (Pre-mitotic gap) | Cell continues to grow; synthesis of proteins and RNA needed for mitosis; preparation for cell division. |
| M Phase (Mitosis) | Cell division occurs (nuclear division followed by cytoplasmic division). |
Based on the functions of the G1 phase, the synthesis of RNA and proteins is a defining activity during this stage.
Important Questions from Cell Cycle and Cell Division
Which scientist explained that cells divide and new cells are formed from pre-existing cells?
The primary function of which channel protein is to transport water across the cell membrane in response to the osmotic gradient created by active solute transport?
A protozoan reproduces by binary fission. What will be the number of protozoans in its population after eight generations ?
Which of the following statements is correct?
Crossing - over occurs between
