Which series of diagrams correctly represents the order of mitosis?
The Correct Answer and Explanation is :
The series of diagrams in mitosis should follow the order of these stages: prophase, metaphase, anaphase, and telophase. Here’s the step-by-step explanation:
1. Prophase:
During prophase, the chromatin condenses into visible chromosomes, each consisting of two sister chromatids held together by a centromere. The nuclear envelope begins to disintegrate, and the spindle apparatus, composed of microtubules, starts to form from the centrosomes, which move to opposite poles of the cell.
2. Metaphase:
In metaphase, the chromosomes align at the metaphase plate (the cell’s equatorial plane). The spindle fibers attach to the centromeres of the chromosomes. This alignment ensures that each daughter cell will receive one copy of each chromosome during the subsequent division.
3. Anaphase:
Anaphase is characterized by the separation of sister chromatids. The spindle fibers shorten, pulling the chromatids apart toward opposite poles of the cell. This ensures that each daughter cell will have an identical set of chromosomes.
4. Telophase:
Telophase is the final stage of mitosis. The separated chromatids, now individual chromosomes, reach the poles of the cell. The nuclear envelope reforms around each set of chromosomes, and the chromosomes begin to decondense back into chromatin. This marks the end of nuclear division.
Cytokinesis:
While technically not part of mitosis, cytokinesis occurs shortly after telophase. This process divides the cytoplasm into two daughter cells, each with a full set of chromosomes and its own nucleus.
In summary, the correct order is:
- Prophase – Chromosomes condense and spindle fibers form.
- Metaphase – Chromosomes align at the cell’s center.
- Anaphase – Sister chromatids are pulled apart.
- Telophase – Chromosomes decondense, and the nuclear envelope reforms.
This sequence ensures accurate genetic material distribution during cell division.