February 2-6

On Monday we learned about how diploid cells are 100% the same as their parent cell. These cells are made with mitosis which splits into two cells from the original cell. First the nucleaic membrane disintigrates. Then the cell goes through DNA replication. Then the DNA unwinds to make chromatins. Then the chromatins combine to make chromotids. Then The chromatids are joined together by a centromere to make a chromosome. They form an X shape. Meanwhile the centrioles start to form spindle fibers. The chromosomes go across the mitosis plain and the spindle fibers attach to the centrioles and pulls the chromosome apart back into chromatids except they are not chromatids anymore they are still chromosomes. Then the cell is pulled in two along with the chromosomes and a new nucleas is formed in both of the new cells. All of this occurs through several stages starting with interphase, prophase, prometaphase, metaphase anaphase, telophase, and cytokinesis. You would think that because the cell is split in two that each cell would only have 50% of the original DNA. But if you look back to the begining of mitosis the cell went through DNA replication which made twice the amount of DNA. So there is enough DNA to go around. Now we also learned that a haploid is a cell with 50% of DNA from the original. Which is produced through sexual reproduction. One process of sexual reproduction is Meiosis which we learned on Tuesday.
On Tuesday we learned about meiosis which is to produce haploid cells like sperm and egg cells. First just like mitosis the nucleaic membrane disapears and DNA replication occurs. Unlike mitosis when the chromatids make the chromosomes the chromosomes pair up into homologus pairs and the pairs crossover and take a peace of eachother. Meanwhile spindle fibers are being formed by the centrioles. The pairs aline along the metaphase plane and the spindle fibers attach to the pairs and pull them apart. Then the two daughter cells form just like in mitosis, but it doesn't stop there. It goes through interphase except there is no DNA replication. Spindle fibers form again and the chromosomes align along the metaphase plate and the spindle fibers pull them apart to make a total of 4 daughter cells.
On Wednsday and Thursday we recapped on it and learned that all of this occurs in stages called interphase, prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis, interphase 2, prophase 2, prometaphase 2, metaphase 2, anaphase 2, telophase 2, and cytokinesis.
On Friday we watched a simulation regarding all of the details at http://cellsalive.com/mitosis.htm.