Answer:
Option). mitochondria.
Explanation:
Cellular respiration can be defined a set of biochemical reactions occur in a cell to provide energy in the form of ATP molecules from complex nutrients. Cellular respiration mainly takes place in the mitochondria.
It is divide into three steps, glycolysis, Krebs cycle, and ETC (electron transport chain). Glycolysis occurs in cytoplasm, but the cellular respiration completes in mitochondria as Krebs cycle and ETC take place in mitochondria.
Thus, the correct option to be filled in the blank is 'mitochondria.'
