Stages of Mitosis: Prophase, Metaphase, Anaphase, Telophase

Mitosis is the division of the nucleus that produces two identical nuclei. Its four stages — prophase, metaphase, anaphase and telophase — move duplicated chromosomes apart in an orderly way. Every stage has clear events that can be seen under a microscope.

Learning these stages matters because mitosis explains growth, wound healing and asexual reproduction. It also helps students read microscope slides and understand how chromosome errors can occur during division.

Key Concepts

In prophase, chromatin condenses into visible chromosomes, each with two sister chromatids; the nuclear envelope begins to break down and spindle fibres form. In metaphase, chromosomes align along the equator, called the metaphase plate. In anaphase, sister chromatids separate at the centromere and move to opposite poles. In telophase, chromosomes decondense, nuclear envelopes reform and two nuclei appear. Spindle fibres attach to the kinetochore, a protein structure at the centromere.

How It Works

1. Prophase prepares chromosomes and builds the spindle.
2. Metaphase arranges all chromosomes in one central line for checking.
3. Anaphase separates sister chromatids so each pole gets one complete set.
4. Telophase rebuilds nuclei around each set.
5. Cytokinesis usually follows, splitting the cell into two.

Worked Example

A cell entering mitosis has 16 chromosomes, each already duplicated. Chromatids present = 16 × 2 = 32. At metaphase, 32 chromatids are arranged as 16 chromosomes on the plate. At anaphase, the 32 chromatids separate: 16 move to one pole and 16 to the other (16 + 16 = 32). After telophase and cytokinesis, each daughter cell has 16 chromosomes, matching the parent cell.

Common Misconceptions

• Students think chromosomes are created in prophase. They exist as chromatin earlier; prophase only condenses them into visible form.
• Many confuse metaphase alignment with separation. Alignment happens in metaphase; separation happens in anaphase.
• Some believe telophase completes cell division. Telophase completes nuclear division; cytokinesis divides the cytoplasm.

Real-World Applications

Pathologists count abnormal mitotic figures to help grade tumours. Root-tip slides in school laboratories show these stages in onion cells. Horticulturists rely on mitotic growth when producing new plants from stem cuttings. Students often identify stages by chromosome position: scattered condensed chromosomes suggest prophase, a neat central line shows metaphase, V-shaped chromatids moving apart indicate anaphase, and two pale groups at the poles mark telophase. Counting these stages in a root-tip slide even lets classes estimate how long each stage lasts relative to the whole division process.

Prophase condenses, metaphase aligns, anaphase separates and telophase rebuilds. Together these four stages of mitosis deliver identical chromosome sets to two new nuclei with remarkable precision.