Meiosis is the process in which a single diploid cell, which has two sets of chromosomes, divides into four haploid cells, which have single sets of chromosomes. Meiosis produces gametes, or sex cells, that are unique. Meiosis includes interphase, prophase I, metaphase I, anaphase I, telophase I, cytokinesis (I), prophase II, metaphase II, anaphase II, telophase II, and cytokinesis (II). In interphase, chromosomes, centrosomes, and, in animal cells, centrioles are duplicated. A centrosome is an area where the mitotic spindle meets and grows out from; the region acts as a mitotic spindle-organizing center. Chromosomes then begin to condense and form x-shaped structures. The nuclear membrane enclosing the chromosomes also breaks down. In prophase I, homologous chromosomes, or two chromosomes that carry the genes that control a specific inherited trait, cross over. In crossing over, the sister chromatids of homologous chromosomes wrap arrange each other and exchange genetic material. Also in this phase, the mitotic spindle begins to form. In metaphase I, the chromosomes line up in the center of the cell and the centrosomes move to opposite poles of the cell. In anaphase I, the mitotic spindle attaches to the kinetochores, which are protein structures, of the chromosomes that are located on the centromeres of the chromosomes. The centromeres is the region where sister chromatids are closest together. Then the spindle pulls the homologous chromosomes away from each other towards the centrosomes. In telophase I, the cell prepares to divide. The moment the cell divides is known as cytokinesis; this is the first time this occurs in meiosis. In prophase II, the mitotic spindle begins to form again. In metaphase II, the chromosomes move to the middle of the cells and the centrosomes move to opposite poles. In anaphase II, the chromosomes are pulled apart by the mitotic spindle towards the centrosomes. In telophase II, nuclei begin to form again and the cells begin to divide. The moment the cells divide is known as cytokinesis; this is the second time this occurs in this process.
I am very satisfied with the outcome of my project. Watching the process of meiosis in this form was helpful in understanding how the process works. However, creating the project was time consuming as pictures of each desired position needed to be taken. Also, the chromosomes were hard to keep track of, as the chromosomes needed to be the same for each phase and correctly divided when necessary. If I were to do this project over again, I would use objects instead of drawings to make the transitions easier.