Since eukaryotic cells require aerobic respiration to produce ATP, a lack of a mitochondria would mean the cell wouldn’t have the necessary energy to live. Therefore, the cell would most likely die due to very low or no energy levels. The cell would have to rely on anaerobic respiration instead, which is much less efficient than aerobic respiration. Scientists have discovered so far that only in the microbe Giardia intestinalis, the cell has evolved to survive without a mitochondria.