How many meiotic divisions are required to produce $100$ functional megaspores in angiosperms?

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.

In which of the following plants is 'dioecy' observed?

Select the correct option from the following statements regarding pollen grains:
$I -$ Pollen grains are rich in nutrients.
$II -$ In recent years,pollen tablets have been used as food supplements.
$III -$ In western countries,a large number of pollen products are available in the market in the form of tablets and syrups.
$IV -$ Pollen consumption has been claimed to increase the performance of athletes and racehorses.
$V -$ Pollen grains can germinate on the stigma after losing their viability.

Which of the following plant parts consist of two generations - one within the other?

The condition in which both male and female reproductive organs are found on the same plant is called: