Chromosome number can be doubled by using which of the following?

Clinostat is the apparatus used to

$I.$ Kinetin is a degradative substance from $DNA$.
$II.$ $ABA$ is present in all plants including lower plants.
$III.$ Low ratio of cytokinin to auxin favours root formation only.
$IV.$ $ABA$ is synthesized catabolically through glycolysis pathway.
Choose the correct combination of options.

If the $Corpora \text{ } allata$ is removed from an insect nymph, what will happen?

Distinguish between:
$(1)$ Cell enlargement and Cell differentiation
$(2)$ Epigeal germination and Hypogeal germination

While eating watermelons, all of us wish it was seedless. As a plant physiologist, can you suggest any method by which this can be achieved?