(N/A) Mitosis is a process of cell division where a single cell divides into two identical daughter cells. It consists of two main events: Karyokinesis (nuclear division) and Cytokinesis (cytoplasmic division).
$1$. Karyokinesis:
It is divided into four main stages:
$(a)$ Prophase: This is the first stage. Chromatin material condenses into compact mitotic chromosomes. Centrioles move to opposite poles. The nucleolus,Golgi bodies,$ER$,and nuclear envelope disappear.
$(b)$ Metaphase: The nuclear envelope completely disintegrates. Chromosomes align at the equator,forming the metaphase plate. Spindle fibers attach to the kinetochores of chromosomes.
$(c)$ Anaphase: Centromeres split,and sister chromatids separate. These daughter chromatids move towards opposite poles,with the centromere leading and arms trailing.
$(d)$ Telophase: Chromosomes reach the poles and decondense. The nuclear envelope,nucleolus,Golgi complex,and $ER$ reform around the chromosome clusters.
$2$. Cytokinesis:
This is the division of the cytoplasm.
- In animal cells: $A$ cleavage furrow forms in the plasma membrane,which deepens to divide the cell into two.
- In plant cells: $A$ cell plate forms in the center and grows outward to meet the existing cell walls,as the cell wall is inextensible.