Meiosis/Reproduction

This is a diagram of meiosis. 



The division of meiosis. 



























Meiosis is the type of cell division by which eggs and sperm are produced. In meiosis I, the chromosomes in a diploid cell resegregate, which produces four haploid daughter cells.  This step in meiosis generates genetic diversity. It occurs in humans, fungi, plants, and animals. Each human cell contains a full set of 46 chromosomes. When meiosis begins, each chromosome is attracted to its special homologous partner. The two number one chromosomes; one from the paternal set and one from the maternal set, wrap tightly with each other in a process called synapsis. Then, a tetrad of four chromosomes is created. Each homologous pair forms its own tetrad, which happens with the other chromosomes. All of the tetrads arrange themselves on the spindle. The chromosomes are pulled apart, and divisions happen. The four chromosomes are separated into two's and then into ones of each tetrad. 


Meiosis II is very similar to mitosis. However, there is no S phase. The chromatids of each chromosome are no longer identical because of recombination. Meiosis II separates the chromatids producing two daughter cells, each with 23 chromosomes and each chromosome has only one chromatid. Homologous chromosomes pair forming bivalents until anaphase I in chromosome behavior. In genetic identity of progeny during meiosis the chromatids are not identical. The daughter cells have a new assortment of parental chromosomes. Meiosis can only happen if the nucleus contains an even number of chromosomes. 


In class we watched the movie Life's Greatest Miracle in which it was about the long processes it takes to have a baby. It was interesting to learn about how a baby is formed by how the process has to be done  right on time. In which, there has to be enough sperm that is developed and the egg can't die. But, the process of having a baby is all about meiosis. This movie really taught me a lot of information about how meiosis is very important, it was gross though watching the live birth of a baby. Meiosis produces different sperm and egg.  In conclusion, I understand about the processes of meiosis and how it is different from mitosis.