My Mitosis

Oh great. Kira just fell down the steps again and got a cut on her arm. This is my time to shine!

Hi, I am a human skin cell who lives on Kira's arm. I have been around here for quite a while, just waiting for the time to split apart to help repair one of Kira's injuries. Right now I am in Interphase, just carrying out my everyday normal functions in being a human cell. Durning this phase, the DNA inside of me has replicated, but has not formed the condense structure of the chromosome. Right now they remain as loosly coiled chromatin. I spend most of my life in this phase, but it's finally time to do something! To repair this cut, I am going to have to divide myself completely in half in order to help stop blood from running out of the cut. The next phase I will be entering is Prophase. Right now my DNA molecules are shortening and condensing by coiling together to form chromosomes. The nuclear membrane surrounding the DNA has now vanished, and the my centrioles have stread to opposite ends of me. Now this stage is complete, I am moving into Metaphase. In this phase, my chromosomes line up in the middle of me, and the spindle fibers from my centrioles attach to the chromosomes.

This next stage I am entering is pretty intense. Now it is time for my sister Chromosomes to seperate; the stage of Anaphase. Now that the spindle fibers are attached to the center of each chromosome, they begin to shorten, pulling the chromosome appart. Ouch! This actually hurts a bit! Luckily everything is going smoothly. There are some pretty serious potential problems that could happen in an error occures. In anaphase, a chromosome could fail to seperate. One daughter cell would recieve both sister chromosomes and the other would recieve none. This results in the former cell having three chromosomes coding for the same thing (two sister and a homologous), a condition known as trisomy, and the latter cell having only one chromosome (the homologous chromosome), a condition known as monosomy. This can eventually lead to cancer. I definatly do not want this to happen for Kira. Now I am at one of the final stages of my cell dividing. During telephase, the chromosomes have reached the poles of their spindlers, and all gather together on their opposite ends of the cell. The spindle fibers disintegrate, and the nuclear membrane reforms around DNA. Now it is time for the final stage of my mitosis; Cytokinesis. With two complete copies of the DNA now in two different regions of me, the cell membrane pinches and divides the cytoplasm in half. I now have a twin! Now i have helped clot Kira's cut so it stops bleeding. Wow that sure was an adventure! I'm now back just preforming my everyday functions as a skin cell, awaiting my next division.