Living organisms, with the exception of viruses, are built from cells, the basic building block, and their products. Growth, repair and reproduction involve the production of new cells from pre-existing ones. A key aspect to this process is the division of the cells genetic material. Since it is the genetic material, inside the nucleus, that determines the function of each cell correct replication of this material is vital.
View the video on the right. Answer the questions below
Before mitosis starts the genetic material is before it starts to coil forming
What grows from the migrating centrioles?
What is the difference between a centromere and a centriole?
What role do the protein fibers originating from the centrioles play?
Mitosis is the process by which the nucleus divides during cell division. This process is divided into several stages. Let's see what differentiates the different stages of mitosis.
A chromatid is one of the two identical copies of DNA making up a duplicated chromosome, which are joined at their centromeres, for the process of cell division. They are called chromatids so long as they are joined by the centromeres. When they separate the strands are called sister chromatids.
Early Prophase is characterised by the genetic material (DNA) condensing into structures called chromosomes, while the nuclear membrane starts to dissolve. Late Prophase is a period during which the chromosomes continue to condense and appear as double chromatids.
Metaphase is characterised by the formation of thread like structures
(the mitotic spindle) made from microtubules and protein. Chromatid pairs
attach to the spindle via the centromere, migrate to the centre of the cell and are ready for the next stage
of mitosis.
Anaphase is marked by the division of the centromeres and the pulling apart of
the chromatid pairs. Once separated from each other the chromatids become
chromosomes as they move to opposite ends of the cell.
Telophase concludes the process of mitosis and involves the formation of two new nuclei around the chromosomes at either end of the cell and the division of the cell through its mid point.
Cytokinesis is the final act of cell division and occurs after mitosis is complete.
Interphase is shown on the right. What process can be seen taking place?
What two processes take place during interphase
Which stage of mitosis is represented by the image that is shown when you Click?.
What stage of mitosis is this?
What is the next stage of mitosis after this one?
