In which plant was the pollen tube discovered by $G.B.M.C.$?

In the figure given below,label the following parts: male gametes,egg cell,polar nuclei,synergid,and pollen tube.

Which one of the following statements is not true?

Study the following statements and choose the correct option.
$I-$ Tapetum nourishes the developing pollen grains.
$II-$ Hilum represents the junction between ovule and funicle.
$III-$ In aquatic plants such as water hyacinth and water lily,pollination is by water.
$IV-$ The primary endosperm nucleus is triploid.

How does vegetative propagation occur in Agave?

$A$ : Continued self-pollination checks inbreeding depression.
$R$ : Pollen release and stigma receptivity are synchronised.