Question
Name and explain the various stages of the cell cycle.
✓
Answer
Stages of the cell cycle :
In interphase, cells grow in size and volume and prepare for the next cell division.
It is divided into three phases :
Mitosis is the division of somatic cells in which two identical daughter cells are produced by the division of one parent cell.
It consists of the following phases :
It occurs in four phases :
- Non-dividing interphase
- Dividing mitotic phase or M phase
In interphase, cells grow in size and volume and prepare for the next cell division.
It is divided into three phases :
- First growth phase ($G_1$) : RNA and proteins are synthesised, and the volume of the cytoplasm increases.
- Synthesis phase (S) : DNA is synthesised and chromosomes are duplicated.
- Second growth phase ($G_2$) : RNA and proteins continue to be synthesised.
Mitosis is the division of somatic cells in which two identical daughter cells are produced by the division of one parent cell.
It consists of the following phases :
- Karyokinesis : It is the division of the nucleus during cell division.
- Cytokinesis : It is the division of the cytoplasm during cell division.
It occurs in four phases :
- Prophase : During prophase, chromatinfibres condense and thick chromosomes are visible. The nucleolus and nuclear membrane disappear. A pair of centrioles duplicates. The spindle apparatus starts forming.
- Metaphase : Chromosomes are arranged on the metaphase plate or equatorial plane.
- Anaphase : The centromere divides, and the sister chromatids separate from each other. Spindlefibres contract and pull chromatids towards opposite poles.
- Telophase : Spindle apparatus disappears. Chromosomes become thin and turn into chromatinfibres. Nuclear membranes and nucleoli reappear.
- The furrow continues to deepen in the cell, and it finally divides the cytoplasm forming two new daughter cells.
- In plant cells, a cell plate appears at the equatorial plane.
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