The photosynthetic stramenopiles obtained their chloroplasts, which are surrounded by three membranes, through
A) primary endosymbiosis.
B) secondary endosymbiosis, retaining the chloroplast from a red alga.
C) secondary endosymbiosis, retaining the chloroplast from a chlorophyte.
D) tertiary endosymbiosis.
E) None of the above

Question

Quizplus · Accepted Answer

The description of chloroplasts surrounded by three membranes is characteristic of chloroplasts obtained through secondary endosymbiosis. In this process, a eukaryotic cell engulfs and retains another eukaryotic cell that has already undergone primary endosymbiosis and possesses a chloroplast. The photosynthetic stramenopiles, also known as diatoms, have undergone secondary endosymbiosis and acquired their chloroplasts from a red alga.

The Photosynthetic Stramenopiles Obtained Their Chloroplasts, Which Are Surrounded by Three