What is the recent definition of protozoa proposed by Cavalier Smith?
They are predominantly cellular eucaryotic microorganisms with often phagotrophic nutrition- without cell walls in their vegetative growth state. However, cell walls are found in spores. Some species have chloroplasts in the cytosol but have no starch. Nor do phycobilisomes, have stacked thylakoids but possess three envelope membranes instead of having two envelope membranes.