The chloroplasts of red algae retain certain pigments of the original cyanobacterial endosymbiont that are absent in green algal chloroplasts.The evolutionary significance of this is that
A) red algae cannot photosynthesize,leading to heterotrophy.
B) neither green algae nor red algae can be classified as protists.
C) chloroplasts likely originated as free-living cyanobacteria.
D) red algae are classified as cyanobacteria.
E) red algae are classified as prokaryotes.

Question

Quizplus · Accepted Answer

The retention of certain pigments by the chloroplasts of red algae suggests that these chloroplasts originated from a cyanobacterial endosymbiont that was incorporated into an ancestral red algal cell. This supports the endosymbiotic theory of chloroplast evolution, which suggests that chloroplasts originated from free-living cyanobacteria that were engulfed by a eukaryotic host cell. The fact that red algae retain specific pigments that are absent in green algal chloroplasts further supports this theory, as it suggests that the original cyanobacterial endosymbiont of red algae had a different pigmentation than the original endosymbiont of green algae.

The Chloroplasts of Red Algae Retain Certain Pigments of the Original