Nuclear Division Lab Report

Discussion
The various stages of nuclear division were observed in this experiment. These stages are prophase, metaphase, anaphase and telophase. There are two types of nuclear division include mitosis and meiosis. Mitotic cell division is involved in the formation of an adult organism from a fertilized egg, asexual reproduction, regeneration, and maintenance or repair of body parts. Mitosis typically results in new somatic, or body cells. Meiosis results in the formation of either gametes in animals or spores in plants. The cells formed have half the chromosome number of the parent cell. Mitosis is best observed in cells that are growing at a rapid pace, such as in the onion root cell tips or at Drosophila giant chromosome. The root tips contain a special growth region called the apical meristem where the
Meiosis consists of two-part nuclear division in which the number of chromosome is halved (haploid) during gamete formation. Meiosis I reduces the number of chromosomes and Meiosis II divides double-stranded chromosome to single strands. Meiosis involves the same four phases seen in mitosis. In prophase I, homologous chromosomes undergo synapsis forming bivalents, crossing over may occur at this time in which case sister chromatids are no longer identical. Crossing over process cannot be observed clearly using this microscope. In metaphase I, homologous chromosome was arranged across the equatorial plane of the spindle. Maternal and paternal homologous chromosomes of each bivalent may be oriented toward either pole. During Anaphase I, the spindle fibers pull whole centromeres, each attached to two chromatids, towards opposite poles of the spindle. This separates the chromosomes into two haploid sets of chromosome in the daughter cells. Telophase I start when the homologous centromeres and their pairs of chromatids arrive at the opposite poles and mark the end of the first meiotic division. (A.Campbell,