Joe Sawaya

Introduction:
Mitosis is a process when a cell divides into 2 daughter cells that genetically identical to each other and to the parent cell. All cells come from preexisting cells by mitosis. Cell division involves a karyokinesis (division of the nucleus) and a cytokinesis (division of the cytoplasm).
Mitosis produces the same number of chromosomes in each daughter cell as in the original nucleus which are inherited form a generation to another. It also causes a growth in the organism by increasing the number of cells.
Not all somatic cells divide; muscle cells, blood cells, cardiac cells, nerve cells don’t divide.
Every cell undergoes a series of steps through its life in a cycle called the cell cycle. It’s divided into 4 stages: the G1 (first gap) phase, the S (synthesis) phase, the G2 (second gap) phase and the M (mitosis) phase.
-In the G1 phase, the DNA begins to replicate, the cell is in a period of growth and cellular activity. Its duration is about 10 hours.
-In the S phase, the DNA is replicated and series of preparation for division occur.
-The G2 phase is a second period of growth and cell’s life. It ends when mitosis begins and its duration is about 4 hours.
These 3 stages are grouped into one phase which is interphase.
-Mitosis is the final stage in the cell cycle. It ends with cytokinesis and its duration is about 1 hour. At its turn, mitosis contains 4 phases: prophase, metaphase, anaphase and telophase which are discussed below.
The process of cytokinesis differs in animal and plant cells; in animal cells, a cleavage furrow occurs and provokes a cytoplasmic division. In plant cells, vesicles from the Golgi complex move to the cell equator and fuse to form a cell plate which divides the cell into 2 daughter cells.

Objectives: * Observe the different steps of mitosis in animal and plant cells * Describe the events