Papaya and date palm are examples of .......... plants.

What is correct for water hyacinth $(Eichhornia \text{ } crassipes)$?
$1.$ Aquatic weed
$2.$ Terrestrial weed
$3.$ Threat to native species
$4.$ Useful to native species
$5.$ Asexual reproduction

What does the product of sexual reproduction generally generate?

Which of the following cells of the embryo sac degenerate after fertilisation in angiosperms?

Pollen grains can be stored for a long period in $......$ at $......$ $^oC$.

Select the correct option for $Strobilanthus$ $kunthiana$ (Neelakurinji).