What did engulfed aerobic prokaryotes become?

Engulfed aerobic prokaryotes evolved into mitochondria through a process known as endosymbiOSis. This symbiotic relationship allowed the host cell to utilize the prokaryotes' ability to perform aerobic respiration, leading to increased energy production. Over time, these engulfed prokaryotes lost their independence and became integral components of eukaryotic cells, contributing to the complexity of life forms.