Endosymbionts

Endosymbionts are microorganisms, such as bacteria, that live inside another organism—in many cases, within the cells of plants or animals. These symbiotic relationships are mutually beneficial; the host provides a protected environment and nutrients, while the endosymbionts often help with vital functions like digestion, nutrient synthesis, or immunity. A well-known example is mitochondria in human cells, which are believed to have originated from ancient bacteria that entered and became integrated into the cells, allowing for more efficient energy production. Endosymbiosis is a key process that has significantly influenced the evolution and functioning of many organisms.