Saturday, April 11, 2015

Mitosis Limericks: Prophase

Download the images for this post.

I was on a limerick kick a few years ago and I did my best to come up with a poem for each phase of mitosis.  Surprisingly these manage to capture most of the main events that students learn from each phase.  Since every textbook has great pictures and descriptions of the phases of mitosis I like to take an alternative approach and use the limericks in class.

(This is the first in a series...four in all.  Stay tuned!)

After showing this limerick I point out that the main events of prophase (and prometaphase):
  1. Condensation of the chromosomes:  Chromosomes condense from loosely-coiled chromatin to more tightly-coiled chromatids (Background information in SciTable.) Since the chromosomes have been replicated condensation produces sister chromatids.
  2. Nuclear Envelope: Dissolution of the nuclear envelope occurs in most cells during mitosis (Background information on NCBI bookshelf).  Dissolution of the envelope is not fully understood but most of the envelope is fragmented into vesicles.  Some yeast cells keep the nucleus in tact throughout mitosis.
  3. Centrioles: Each centriole is two cylinders of mircotubules (Background information).  The microtubules that eventually connect to the chromosomes are assembled near the centrioles.  Not all cells have centrioles...they are common in animal cells and rare in plant cells.
Thanks!

1 comment: