Protozoa — select the statement that is NOT true (focus on walls, spores, trophozoites, and planktonic group membership).
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AProtozoa generally lack a rigid cell wall
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BProtozoa do not produce true spore-bearing structures like fungi
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CProtozoa comprise the photosynthetic community known as phytoplankton
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DProtozoa form active feeding stages called trophozoites
Answer
Correct Answer: Protozoa comprise the photosynthetic community known as phytoplankton
Explanation
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:
Assess cell wall claim: protozoa lack rigid walls ✔Assess spore claim: they do not make fungal-type spore-bearing bodies; some have spore-like stages but not fungal sporangia ✔Assess trophozoite claim: trophozoites are well known ✔Assess phytoplankton claim: false; protozoa are zooplankton ✘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