Which method of asexual reproduction is observed in $Spirogyra$?

Which of the following two sex hormones are produced by the human female ovary?

Which method of propagation allows for the combination of desirable traits in plants?

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

$(a)$ List two reasons for the appearance of variations among the progeny formed by sexual reproduction.
$(b)$ $(i)$ Name the part marked '$A$' in the diagram.
$(ii)$ How does '$A$' reach part '$B$'?
$(iii)$ State the importance of the part '$C$'.
$(iv)$ What happens to the part marked '$D$' after fertilisation is over?

Why do we need to adopt contraceptive measures?