Meiosis

Hi, Joe Bob’s here. I’m pretty sure I last left you in the study of mitosis. Mitosis is very similar to our study today, Meiosis. Now, In Meiosis there is only one more phase for each stage of Meiosis, then Mitosis. Let’s see where I’m heading first in my Magical Meiosis journey. Let Maryann tell you about the back round of Meiosis. “Well, Joe Bob! As you and me both know, Meiosis is used for producing Gametes and sex cells. Gametes are basically sex cells; egg cells are gametes, and sperm cells as well, when they meet up, there is fertilization happening. In which the female gametes, and the male gametes come together and produce. Meiosis has two divisions, which is why; there is two of Prophase, two of Metaphase, and so…on. Also, in your journey you will come to find out that, the Meiosis process is a lot longer then Mitosis” “Now Joe Bob, off with your journey.” As I say goodbye to Maryann, whom was very helpful. I run in to Interphase, the first phase in Meiosis. “Hi Joe.” Says the phase. “Hello” I say. “What brings you to area?” he asked. “Well, I was just wondering if you could explain to me, what does do on in this phase?” I asked. “Well, that’s easy.” “First, the cell replicates it’s chromosomes, and is left with two sister chromotids which are held together by a Centromere.” Says Interphase. “But move on to Prophase 1 to find out much more.” He continues. As I follow the path down to Prophase 1. I saw the chromosomes double up and then combine again. I notice that this didn’t happen in Mitosis. I hurried along to Prophase 1 to ask what was with this abnormal behavior. “Why were all the chromosomes combining twice?” I asked. “Well, in this division, the chromosomes, pair up in 2 homologous chromosomes, each made up of two sister chromotids, and this is called a tetrad.” Prophase explains to me. “Okay, well then what is this process called?” I ask. “ This process is what we call synapsis.” Prophase 1 explains. “Alright…Wait, what are they doing now? ”I exclaim. “Ohh…that is crossing over.” He tells me. “Ohh…I see, the genetic material is being moved to different locations. But what does that do for the cell?” I ask. “It is simple, crossing over, as we call it, is just the exchanging of genetic material, it gives the cell genetic variation.