The key difference between metaphase 1 and 2 is that in metaphase 1, homologous chromosomes pair up at the metaphase plate while in metaphase 2, single chromosomes line up at the metaphase plate.
Meiosis is the process that converts a diploid cell into four haploid cells during the gamete formation. It is an important process since it increases the genetic diversity among the offspring. Meiosis is vital in sexual reproduction due to its importance in haploid cell formation. Meiosis occurs via two successive nuclear divisions called meiosis I and meiosis II. Each nuclear division can be subdivided again into Prophase, Metaphase, Anaphase and Telophase. Hence, metaphase is the stage of cell division in which the chromosomes arrange along the Metaphase plate. Metaphase 1 can be found in meiosis I while metaphase 2 can be found in meiosis II. Metaphase 1 and 2 are different from each other.
CONTENTS
1. Overview and Key Difference
2. What is Metaphase 1
3. What is Metaphase 2
4. Similarities Between Metaphase 1 and 2
5. Side by Side Comparison – Metaphase 1 vs 2 in Tabular Form
6. Summary
What is Metaphase 1?
Metaphase 1 is the metaphase of meiosis 1. During this phase, the pairs of homologous chromosomes arrange on the metaphase plate of the cell, and then they bind to the meiotic spindle through centromeres. At this moment, the centrioles can be seen at the opposite poles of the dividing cell.
Figure 01: Metaphase 1
The pairs of homologous chromosomes get attached to the spindle fibres from each pole, at the opposite sides. At this stage, the cell contains a full set of chromosomes. Metaphase 1 occurs after prophase 1. Anaphase 1 is the next phase after metaphase 1.
What is Metaphase 2?
The metaphase found in meiosis 2 is known as metaphase 2. The events happening in metaphase 2 are similar to the metaphase of the mitosis. During the metaphase 2, single chromosomes arrange in the metaphase plate.
Figure 02: Metaphase 2
Hence it is different from the metaphase 1 since pairs of homologous chromosomes arrange in the metaphase plate. Then to each centromere of the chromosome, spindle fibres from each pole attach. At this stage, the cell contains half of the chromosomes that of in the parent cell. Metaphase 2 occurs after prophase 2. Anaphase 2 is the next phase after metaphase 2.
What are the Similarities Between Metaphase 1 and 2?
- Metaphase 1 and 2 are phases of meiosis.
- They involve for the formation of gametes from diploid cells.
- In both phases, chromosomes come into the middle of the cell.
- Furthermore, spindle fibres attach with centromeres of the chromosomes in each phase.
What is the Difference Between Metaphase 1 and 2?
Meiosis occurs through two cycles, which are meiosis 1 and 2. Each meiotic cycle has four subphases. Metaphase of the meiosis 1 is known as metaphase 1 while metaphase of the meiosis 2 is known as meiosis 2. In metaphase 1, pairs of homologous chromosomes line up at the middle of the cell while single chromosomes line up at the middle in metaphase 2. This is the difference between metaphase 1 and 2.
Another major difference between metaphase 1 and 2 is that, in metaphase 1, the spindle fibres get attached to two centromeres of each homologous chromosome whereas, in metaphase 2, the spindle fibres get attached to one centromere from both sides.
The below infographic presents the difference between metaphase 1 and 2 in tabular form for quick reference.
Summary – Metaphase 1 vs 2
Meiosis is one of the two types of cell divisions. It requires the sexual reproduction for the formation of gametes. Meiosis has two major cycles namely first meiotic cycle and second meiotic cycle, and at the end, it results in four haploid daughter cells from a single diploid cell. In each meiotic cycle, there are four main phases. They are prophase, metaphase, anaphase and telophase. Metaphase 1 belongs to meiosis 1, and metaphase 2 belongs to meiosis 2. During the metaphase 1, pairs of homologous chromosomes arrange at the middle of the cell while in metaphase 2, single chromosomes arrange at the middle. This is the difference between metaphase 1 and 2.
Reference:
1.“Meiosis.” Khan Academy, Khan Academy. Available here
Image Courtesy:
1.”Meiosis Stages”By Ali Zifan – Own work (CC BY-SA 4.0) via Commons Wikimedia
2.”Figure 11 01 04″By CNX OpenStax , (CC BY 4.0) via Commons Wikimedia