Some interesting science facts...
The hereditary material of the nondividing or interphase cell is contained in a compact body, the nucleus. Most nuclei divide (reproduce) by a process called mitosis. Near the nucleus in animal cells are two small bundles of rods, the centrioles, which lie at right angles to each other.
As division begins, the centrioles seperate and move to opposite poles of the cell. As the centrioles move, they are surrounded by a system of micro tubes, the asters. At the same time the nuclear membrane disintegrates and the nuclear material condenses and coils to form visible chromosomes. Each chromosome is divided lengthwise into two sister chromatids which are joined at a constriction called the centromere. Microtubules connect the centromeres of each chromosome to the centrioles, and the chromosomes then move to the equatorial plane of the cell (equidistant from the centrioles). The sister chromatids seperate and are then called daughter chromosomes.
The daughter chromosomes begin moving toward opposite centrioles. When the chromosomes stop moving, a re-organization takes place which usually involves cytoplasmic division and nuclear reformation. This produces two interphase (daughter) cells. During the interphase, each chromosome reproduces itself; thus, new sister chromatids are present for the next division.
As division begins, the centrioles seperate and move to opposite poles of the cell. As the centrioles move, they are surrounded by a system of micro tubes, the asters. At the same time the nuclear membrane disintegrates and the nuclear material condenses and coils to form visible chromosomes. Each chromosome is divided lengthwise into two sister chromatids which are joined at a constriction called the centromere. Microtubules connect the centromeres of each chromosome to the centrioles, and the chromosomes then move to the equatorial plane of the cell (equidistant from the centrioles). The sister chromatids seperate and are then called daughter chromosomes.
The daughter chromosomes begin moving toward opposite centrioles. When the chromosomes stop moving, a re-organization takes place which usually involves cytoplasmic division and nuclear reformation. This produces two interphase (daughter) cells. During the interphase, each chromosome reproduces itself; thus, new sister chromatids are present for the next division.