Meiosis is long and boring—blah!

Let’s all learn something today! Watch it with some higher quality too.

Meiosis works in several stages, starting with Interphase.

Cell into anaphase

Image via Wikipedia

In interphase, a cell grows to its full size, and duplicates its chromosomes. You end up with multiple pairs of identical chromatids stuck together. You still can’t see them though, it’s just a bunch of goop. The centrioles also duplicate here.

You now get into Meiosis 1, which starts with prophase 1. This is the longest part of meiosis. Here, the chromatin condense into visible chromosomes. Now, through synapsis, homologous chromosomes, or chromosomes that control the same genetic characteristics, pair up. You now have a group of four chromatids that is called a tetrad. These pairs also swap similar segments while “crossing over”.

Now in Metaphase 1, the nuclear membrane is gone and the separated centromeres have spindles that form between them. The chromosomes move towards the metaphase plate as the microtubules attach to their centromeres.

Moving into Anaphase 1, the tetrads split up as the microtubules become shorter. The chromosomes are pulled apart from each other and therefore the homologous chromosomes are separated.

Now in Telophase 1, nuclear membranes form around the two sets of chromosomes. The sister chromatids in this are not the same due to them “crossing over”. The cell is split in two and two daughter cells are formed.

In prophase 2, the new nuclear membranes break down and spindles form again.

In metaphase 2, the spindle fibers attach to both sides of the chromosome centromeres.

Now in anaphase 2, the spindle fibers shorten and pull the chromatids apart.

Moving into telophase 2, new membranes form around the sets of chromosomes. The cells now split into four as well and there are now four haploid daughter cells.


Credits: Music is “Dane Street” by Goldmund. Text is a copy-paste from the video description.