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

3. Abnormalities of mitosis
1- Non dis-junction of chromosomes.
2- Un usual mitotic figures by rapidly proliferation cells of malignant tumours.

4. Stages 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.

6. Factors 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