Protozoa — select the statement that is NOT true (focus on walls, spores, trophozoites, and planktonic group membership).

Introduction:
This classification question checks whether you can separate protozoa from algae and fungi by key biological traits and ecological roles in aquatic systems.

Given Data / Assumptions:

• Traits assessed: cell wall presence, spore structures, trophozoite stage, and planktonic grouping.
• We must choose the statement that is not true.

Concept / Approach:
Protozoa are heterotrophic eukaryotes, typically lacking a rigid cell wall. Many alternate between trophozoites (active feeders) and cysts (dormant). They are part of zooplankton, not phytoplankton, because they are not primarily photosynthetic; phytoplankton consists mainly of algae and cyanobacteria.

Step-by-Step Solution:

Verification / Alternative check:
Introductory microbiology texts define phytoplankton as photosynthetic producers; protozoa are consumers/predators in aquatic food webs.

Why Other Options Are Wrong:

• Cell wall absence: correct portrayal.
• No spore-bearing structures like fungi: correct; cysts are different.
• Trophozoites: accurate life-stage term.

Common Pitfalls:
Confusing spore-like oocysts of some parasites with fungal sporangia; mixing up phyto- (producers) vs zoo- (consumers) plankton.

Final Answer:
Protozoa comprise the photosynthetic community known as phytoplankton