How are mitochondria and chloroplasts thought to have been incorporated into eukaryotic cells through the process of endosymbiosis?

Mitochondria and chloroplasts are thought to have been incorporated into eukaryotic cells through endosymbiOSis, a process where a larger cell engulfed smaller prokaryotic cells. Over time, these smaller cells evolved a mutually beneficial relationship with the larger cell, eventually becoming specialized organelles within the eukaryotic cell. This theory is supported by evidence such as the similarities between these organelles and modern-day bacteria, as well as their own DNA and ability to replicate independently within the cell.