Evidence of endosymbiotic theory suggests that cells engulfed mitochondria for what purpose? randomly unintentionally by exocytosis for food

Endosymbiotic theory proposes that mitochondria, which are crucial for energy production in eukaryotic cells, were once free-living prokaryotes that were engulfed by ancestral eukaryotic cells. This engulfment wasn't random; instead, it provided a highly efficient way for these host cells to generate ATP, allowing them to thrive in increasingly oxygen-rich environments. Over time, a mutually beneficial relationship evolved, as the engulfed mitochondria supplied energy while enjoying a stable environment! Interestingly, this theory doesn't just explain the origin of mitochondria; it's also the reason why mitochondria have their own DNA, which is distinct from the nuclear DNA of the host cell. This piece of genetic evidence provides fascinating insights into evolutionary biology and how collaboration can lead to complex life forms. Just think of it as the ultimate partnership in the cellular world!