Metaphase is the second step of mitosis division after prophase. Metaphase is characterised by the alignment of the duplicated chromosomes at the equatorial plate known as the metaphase plate. One of the sister chromatids is attached to the one pole of the cell by microtubules attached to its kinetochore and the other sister chromatid gets attached to the opposite pole.
Key features of Metaphase
- Chromosomes are completely condensed and can be seen under the microscope.
- The nuclear envelope disintegrates completely and chromosomes are present in the cytoplasm.
- Sister chromatids are attached to each other at centromere by a protein complex called cohesin.
- Microtubules bind to the kinetochore of sister chromatids. The kinetochore is a multiprotein complex attached to each centromere.
- Sister chromatids get attached to kinetochore microtubules coming from opposite poles.
- Microtubules attached to kinetochore pull sister chromatids back and forth until they get aligned at the equatorial plate or metaphase plate in the middle of the cell.
- Metaphase ensures an equal division of chromosomes in the daughter cells.
- Karyotyping is generally done at this stage for research and finding chromosomal abnormalities.
- Colchicine, an alkaloid derived from the corm of Colchicum autumnale, arrests cell division at metaphase. It interferes with the formation of spindle fibres.
Metaphase is followed by Anaphase, which is characterized by separation and movement of sister chromatids to the opposite poles.
This was a brief note on Metaphase. Explore notes on mitosis, meiosis and other important concepts related to NEET, only at BYJU’S.