[Campbell Biology P.666] Which group is correctly paired with its description? | Practice Question

Which group is correctly paired with its description?

A: diatoms—important consumers in aquatic communities
B: diplomonads—protists with modified mitochondria
C: apicomplexans—producers with intricate life cycles
D: red algae—acquired plastids by secondary endosymbiosis

Explanation

Diplomonads, such as Giardia, are known for having highly reduced mitochondria called mitosomes, which is a characteristic modification. Diatoms are primary producers photosynthetic forming the base of many aquatic food webs. Apicomplexans are parasitic protists with complex life cycles, not producers. Red algae, along with green algae, are part of the Archaeplastida supergroup and acquired their plastids through primary endosymbiosis, not secondary. Secondary endosymbiosis refers to a eukaryotic cell engulfing another eukaryotic cell that already contains plastids.