Why does menstruation occur?

What is menstruation?

When does condensation occur in atmosphere ?

On which day after fertilization, does implantation occur?

Where and when does replication occur?

On which day does the ovulation occur in human female ?

The events of the menstrual cycle in Homo sapiens are represented beloW.Answer the following questions.Why is there no menstruation eycle upon fertilization ?

What is menstruation ?Explain.

How does urine formation occur in human?