Stages of mitosisStages of mitosis•The stages are prophase, metaphase, anaphase and telophase.

Abnormalities of mitosisAbnormalities of mitosis

• 1- Non dis-junction of chromosomes.

• 2- Un usual mitotic figures by rapidly proliferation cells of malignant tumours.

Stages of meiosisStages of meiosis• 1- First meiotic division include

Prophase I ,Metaphase I, Anaphase I and Telophase I

• Prophase I include Leptotene, Zygotene, Pachytene, Diplotene and Diakinesis.

• 2- Second meiotic division include Prophase II, Metaphase II, Anaphase II and Telophase II.

Factors affecting in cell divisionFactors affecting in cell division•1 -Radiation ( X-ray).

•A) – Arrest of mitosis Lethal dose ( High dose).

•B) – Mutation ( mutagenic effect) not lethal dose ( Low dose).

•2 -Drugs include Colchicine , Vincristine, Vinblastine are anti-mitotic drugs which inhibit the formation of microtubules and arrest of mitosis in metaphase.

•Their effect is reversible