Mitochondria and chloroplasts likely evolved from engulfed prokaryotes that once lived as independent organisms. At some point, a eukaryotic cell engulfed an aerobic prokaryote, which then formed ...

What Is the Origin of Chloroplasts? Like mitochondria, chloroplasts likely originated from an ancient symbiosis, in this case when a nucleated cell engulfed a photosynthetic prokaryote.

Photosynthesis occurs in chloroplasts ... as cellulose found in the cell walls and starch used as energy storage. The glucose can also be broken down in the plant by respiration.

Scientific consensus is that this happened twice over the course of evolution, resulting in the energy-generating organelles known as mitochondria ... to chloroplasts perform for the host cell?" ...

Photosynthesis occurs in chloroplasts ... as cellulose found in the cell walls and starch used as energy storage. The glucose can also be broken down in the plant by respiration.