Where are the female germ cells located in a flower?

Length of pollen tube depends on the distance between

Which among the following statements are true for unisexual flowers?
$(i)$ They possess both stamen and pistil.
$(ii)$ They possess either stamen or pistil.
$(iii)$ They exhibit cross-pollination.
$(iv)$ Unisexual flowers possessing only stamens cannot produce fruits.

$(a)$ 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?

List any two differences between pollination and fertilization.

What are those organisms called which bear both the sex organs in the same individual? Give one example of such an organism.