Which of the following organism pairs is/are an example of secondary endosymbiosis?
I.red algae-heterotrophic eukaryote
II.green algae-heterotrophic eukaryote
III.E.coli bacteria-photosynthetic cyanobacterium
IV.Chlamydomonas and Gonium
A)I only
B)III and IV
C)I and II
D)II and III

Question

Quizplus · Accepted Answer

Secondary endosymbiosis occurs when a eukaryotic host cell engulfs another eukaryotic cell that has already undergone primary endosymbiosis. This is seen in cases where a heterotrophic eukaryote engulfs a photosynthetic eukaryote, such as red or green algae, leading to a complex relationship where the engulfed cell functions within the host. Options I and II (red algae-heterotrophic eukaryote and green algae-heterotrophic eukaryote) are examples of this process. E.coli and cyanobacteria, as well as Chlamydomonas and Gonium, do not fit the criteria for secondary endosymbiosis.

Which of the Following Organism Pairs Is/are an Example of Secondary