Final answer:
Yes, chloroplasts are descendants of cyanobacteria. The hypothesis of endosymbiosis explains this process, and multiple lines of evidence support it. The correct option is A) Yes
Step-by-step explanation:
Yes, chloroplasts are descendants of cyanobacteria.
In a process called endosymbiosis, an ancestral prokaryote engulfed a photosynthetic cyanobacterium that evolved into modern-day chloroplasts.
This hypothesis was proposed by Lynn Margulis and is supported by several lines of evidence, including similar DNA sequences between photosynthetic cyanobacteria and green algae, the presence of a vestigial nucleus in the green algal endosymbiont, and the identification of four membranes around the chloroplasts, which correspond to different structures involved in the endosymbiotic event.
The acquisition of cyanobacterial endosymbionts has happened twice in the history of eukaryotes, with most photosynthetic eukaryotes being descended from the first event. The correct option is A) Yes