What happens when
(i) Planaria gets cut into two pieces
(ii) A mature Spirogyra filament attains considerable length?
(iii) On maturation sporangia burst?

Explanation

(i) Each piece regenerates into a new planaria.
(ii) Its filaments breaks into smaller pieces/fragments and each fragment gives rise to a new filament.
(iii) It releases spores which germinate into new mycelium in moist conditions.