Which cell structure is involved in energy production and is only found in eukaryotic cells?

Mitochondria are known as the powerhouse of the cell due to their critical role in energy production through the process of oxidative phosphorylation. Eukaryotic cells, which include animal, plant, fungi, and protist cells, possess mitochondria that generate ATP (adenosine triphosphate) by converting nutrients into energy.

The unique feature of mitochondria is their double-membrane structure and the presence of their own DNA, which is separate from the nuclear DNA. This indicates that they are semi-autonomous organelles that originated from an ancestral prokaryotic cell through endosymbiosis, a process that led to the evolution of eukaryotic cells. This feature is distinct to eukaryotes, as prokaryotic cells, such as bacteria and archaea, do not have mitochondria; instead, they perform energy production in their cell membrane.

Other options like ribosomes are found in both eukaryotic and prokaryotic cells, as they are essential for protein synthesis. The nucleoid is a region found in prokaryotic cells where genetic material is located; thus, it is not exclusive to eukaryotes. The cytoplasm is the cellular fluid present in all cell types