in this case when a nucleated cell engulfed a photosynthetic prokaryote. Indeed, chloroplasts resemble modern cyanobacteria, which remain similar to the cyanobacteria of 3 million years ago.

More information: Denghui Zhu et al, Cyanobacteria-intelligent biohybrid system enables light-guided tumor-associated macrophage-specific siRNA delivery, Cell Reports Physical Science (2024).