Meiosis I

This process is visually represented in the meiosis diagram above. The meiosis is divided into two sub part Meiosis I and meiosis II.

Prophase I

Leptotene: Chromosomes uncoil, resembling thread-like shapes with bead-like structures called chromomeres. Chromosomes are directed toward centrioles, creating a bouquet appearance (Bouquet Stage).
Zygotene or Synaptotene: Synapsis i.e. pairing of homologous chromosomes begins. A synaptonemal complex stabilizes pairing and facilitates recombination or crossing over. Synapsis can start at various points along chromosomes (pro terminal synapsis), end at centromeres (pro-centric pairing), or at random points.
Pachytene: The chromosomes are twisted around each other, becoming indistinguishable. Each of the homologous chromosomes splits lengthwise and forms two chromatids connected by a common centromere. It forms bivalent or tetrad Chromosomes. The exchange of genetic material between homologous chromosomes is an important step in crossing over. An endonuclease enzyme breaks down non-sister chromatids at the crossing-over site. Interchange of chromatid segments occurs between non-sister chromatids, facilitated by ligase.
Diplotene: The synaptonemal complex has dissolved and the chromatids are physically joined to each other at its specific points, called chiasmata. Chiasmata are moving in a zipperlike way toward the chromosome’s end.
Diakinesis : Bivalent chromosomes become more compact and evenly distributed in the nucleus. The nuclear envelope’s going to break down, the nucleolus’s going to disappear. Chiasmata are reaching the ends of chromosomes, while chromatids continue to stay attached until metaphase.

Metaphase I

The spindle fibers are attached to the chromosomes.
Chromosomes are located at the equator.
Spindle fibers connect to centromeres of homologous chromosomes, directed toward opposite poles.

Anaphase I

Homologous chromosomes divide and move to the opposite poles.
Chromosomal fibers or microtubules shorten, pulling each chromosome with two chromatids and an undivided centromere.
The formation of chiasma results in nongenetically related chromatids on a chromosome.

Telophase I

Chromosomes move to opposite poles.
In the vicinity of the chromosomes, a new nuclear envelope forms.
Chromosomes relax, and nucleolus reappear.
Two daughter nuclei are created.

Cytokinesis I

Cell membrane constriction divides cells in animals, whereas in plants a cell plate forms to form two daughter cells.

Diagram of Meiosis

The diagram of meiosis helps us understand the process of cell division and the formation of gametes (sex cells) with half the number of chromosomes as the parent cell. The diagram of meiosis class 9 is an important question that is often asked in examinations. The meiosis diagram with explanation is given here.

The labelled simple diagram of meiosis is given below:

Table of Content

What is Meiosis?
Meiosis Stages
Interphase
Meiosis I
Meiosis II
Conclusion – Diagram of Meiosis
Related Diagram Article Links
FAQs on Meiosis Diagram