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

Length of pollen tube depends on the distance between

$(a)$ 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?

$(a)$ Give the functions of $(i)$ Stigma $(ii)$ Ovary. $(b)$ State in brief the formation of seed in a flower.

Which part of the plant is the reproductive organ?

Differentiate between plumule and radicle.