![]() ![]() The spindle fibers attach to the chromosomes and begin to move them to the center of the cell as they do in mitosis. One kinetochore forms on each chromosome instead of on each chromatid as in mitosis. They hold the chromosomes together until they separate during anaphase.Ĭrossing over between homologous chromosomes is likely to occur at several different points, resulting in chromosomes that are mixtures of the original two chromosomes. When the chromosomes partially separate in late prophase, the areas where crossing over occurred remain attached and are referred to as Chiasmata (sing. The two chromosomes may exchange fragments by a process called crossing over. ![]() Synapsis (joining) of homologous chromosomes produces tetrads (also called bivalents). One kinetochore forms per chromosome rather than one per chromatid, and the chromosomes attached to spindle fibers begin to move. It is much longer in meiosis than in mitosis. Prophase I is by far the most complicated phase of meiosis. Each of these phases are similar but not identical to the corresponding mitosis phases. Meiosis II (Second division) includes Prophase II, Metaphase II, anaphase II and telophase II. Meiosis I includes Prophase I, Metaphase I, Anaphase I and Telophase I. It is divided into two steps: meiosis I and meiosis II. ![]() Meiosis involves a reduction in the amount of genetic material. MORE DETAIL 3.) Crossing Over During the middle of prophase I, homologous chromosome undergo synapsis, or pairing up. During the beginning of this stage, the chromosomes condense. The first stage of Meiosis I is prophase I. Meiosis is the type of cell division by which germ cells (eggs and sperm) are produced. Prophase I Meiosis is divided into two phases, beginning with Meiosis I. ![]()
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