DISCUSSION RESPONSE – SUBJECT ANATOMY AND PHYSIOLOGY
Mitosis is the process that involves the formation of two new daughter cells that carry the same amount of chromosomes as the parent. There are different phases in mitosis: Interphase, Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis. Interphase is the first phase in mitosis where preparation of replication occurs. There are three other stages in this phase: G1, S, and G2. Duplication of organelles and other parts except chromosomes occurs in G1. In the S stage, this is where the chromosomes duplicate and G2 functions as the checkpoint. If a mistake was made during the process, it is in G2 where they find that mistake. During Prophase, chromosomes are formed while the nuclear membrane starts to breakdown. Centrioles begin to move away from each other to opposite sides at the same time allowing spindle fibers to form. Metaphase is where movement of the spindles to the center occurs and chromosome pairs come to alignment in the center. Separation of the sister chromosomes occur in Anaphase. This is where grooves are formed as well. In Telophase, chromatin are finally formed and the nuclear membranes are created while the spindle begins to dissolve. Finally, the formation of two daughter cells are formed during Cytokinesis.
Meiosis is the process of genetically making four different cells. It also has different phases: Interphase, Prophase I, Metaphase I, Anaphase I, Telophase I, Cytokinesis, Prophase II, Metaphase II, Anaphase II, Telophase and Cytokinesis. Interphase is the first phase where there are four chromosomes in the cell. It contains an S stage where DNA is copied. Prophase is where the chromosomes come together and share genetic materials. This process is called synapsis. During Metaphase, chromosomes line up in the middle on the metaphase plate. They are arranged in different ways on the plate. This is where spindles form and attach to the centrioles (opposite sides) that attach to chromosomes. In Anaphase I, chromosomes are separated and moved to opposite sides. Two chromosomes to one side and two chromosomes to the other. Formation of new nuclei on each side occurs in Telophase. The division of the cell into two parts takes place in the Cytokinesis phase. Prophase II is where no more sharing of genetic materials occur. Metaphase II is where the pair of chromosomes align in the middle of each cell. During this phase, spindles once more connect centrioles to chromosomes. Chromosomes move to opposites sides in Anaphase II. And finally, during Telophase and Cytokinesis, division occurs forming four different cells.