Biology Project
Dania Abu Zahra, Hadeel Kashash, Nada Mubarak, Reem Al Ahbabi
What is Mitosis?
Mitosis is the process by which a cell, which has previously replicated each of its chromosomes, separates the chromosomes in its cell nucleus into two identical sets of chromosomes, each set in its own new nucleus. It is a form of nuclear division. It is generally followed immediately by cytokinesis. Mitosis and cytokinesis together define the mitotic (M) phase of the cell cycle—the division of the mother cell into two daughter cells, genetically identical to each other and to their parent cell. This accounts for approximately 10% of the cell cycle.
The process of mitosis is fast and highly complex. The sequence of events is divided into stages. These stages are:
1- Prophase
2- Metaphase
3- Anaphase
4- Telophase.
The primary result of mitosis is the transferring of the parent cell's genome into two daughter cells. These two cells are identical and do not differ in any way.
Genome is the entirety of an organism's hereditary information.
ii) Prophase
In prophase, the nuclear envelope breaks down and spindles form at opposite "poles" of the cell. Many consider prophase (versus interphase) to be the first true step of the mitotic process.
What are the changes that occur in a cell during prophase?
Chromatin fibers become coiled into chromosomes with each chromosome having two chromatids joined at a centromere.
In the cytoplasm, the mitotic spindle, consisting of microtubules and other proteins, forms between the two pairs of centrioles and centrosomes as they migrate to opposite poles of the cell.
The nuclear envelope disappears at the end of prophase.
ii) Metaphase
Is a stage of mitosis in which condensed and highly coiled chromosomes, carrying genetic information, align in the middle of the cell before being separated into each of the two daughter cells.