For approximately how many days does menstruation last in human females?

Which of the following is an artificial method of vegetative propagation?

What should the temperature of the testes be relative to the body temperature for the production of sperm?

'Regeneration is not reproduction'. Justify this statement with reason.

What is placenta? Describe its structure. State its functions in case of a pregnant human female.

In the given figure,label the parts and mention their functions:
$(a)$ Production of egg
$(b)$ Site of fertilisation
$(c)$ Site of implantation
$(d)$ Entry of the sperms