The organelle responsible for cellular respiration in animal cells (and most other eukaryotic cells) is the mitochondrion.

Here's why:

* Cellular Respiration: This process breaks down glucose (sugar) in the presence of oxygen to produce ATP, the cell's primary energy source.

* Mitochondria: These organelles are often referred to as the "powerhouses" of the cell because they are where the majority of ATP production takes place. They have their own DNA and ribosomes, suggesting an ancient symbiotic relationship with eukaryotic cells.

While other organelles play roles in cellular processes, the mitochondrion is uniquely equipped for the complex series of chemical reactions involved in cellular respiration.