Differentiation of zoospore takes place in the vesicle, is the main characteristic of –

Correct option is B

Correct option: (b) Pythium spp.
· Pythium produces zoospores inside a vesicle, where differentiation occurs before release.
· This is a typical feature of many species of Pythium (Oomycetes).
Other options:
· (a) Aspergillus – A fungus producing conidia, no zoospore stage.
· (c) Phytophthora – Zoospores form inside sporangia but not differentiated in a vesicle.
· (d) Uncinula – A powdery mildew fungus; no zoospore formation.