Which organisms lack mitochondria yet can perform cellular respiration under specific conditions?

Prokaryotic organisms, such as certain bacteria, lack mitochondria but are capable of performing cellular respiration, albeit in different ways compared to eukaryotic cells. In prokaryotes, respiration occurs in the cell membrane where the electron transport chain is located, allowing these organisms to generate ATP through processes like anaerobic respiration or fermentation when conditions do not favor aerobic respiration.

This ability to perform cellular respiration under anaerobic conditions is particularly evident in organisms such as obligate anaerobes, which thrive in environments devoid of oxygen and utilize different electron acceptors. Additionally, some facultative anaerobes can switch between aerobic and anaerobic respiration depending on the availability of oxygen, demonstrating their metabolic flexibility in energy production.

Eukaryotic organisms, such as plants, animals, and fungi, typically possess mitochondria and carry out aerobic respiration primarily within these organelles. While fungal and plant organisms also fall under the eukaryotic category, they are not characterized as lacking mitochondria. The distinction of prokaryotes is essential as it reflects their unique cellular architecture and metabolic pathways.