At approximately what age does menstruation permanently cease in females?

$A$ part of the male reproductive system is shown below. Study the diagram and answer the questions that follow.
$(a)$ Two parts have been incorrectly labelled. Identify them.
$(b)$ Give the function of urethra.
$(c)$ Which hormone is released by testis?

What happens if the egg is not fertilized?

Why does the lining of the uterus become thick and spongy every month?

Write true or false for the following statement: Menstruation lasts for about ten to fifteen days.

What changes are observed in the uterus subsequent to implantation of the young embryo?