primary endosymbiosis

Primary endosymbiosis is a process where a larger cell engulfs a smaller, photosynthetic bacteria, which then becomes a permanent part of the host. Over time, this bacteria evolves into a specialized organelle called a chloroplast, enabling the host cell to perform photosynthesis—converting sunlight into energy. This event was crucial in the evolution of plants and algae, as it introduced the ability to produce own food using sunlight, shaping much of life’s diversity. Essentially, primary endosymbiosis is the foundational event where photosynthetic eukaryotic cells first originated.