What organelle did the photosynthetic prokaryotes become?

Photosynthetic prokaryotes, such as cyanobacteria, are believed to have evolved into chloroplasts through a process called endosymbiOSis. This theory suggests that early eukaryotic cells engulfed these prokaryotic organisms, which then became integrated into the host cell as organelles. Over time, chloroplasts retained their own DNA and machinery for photosynthesis, enabling the eukaryotic cells to harness solar energy. This evolutionary event was crucial for the development of plants and algae, significantly impacting Earth's ecosystems.