Here's why:
* Mitochondria are the "powerhouses" of the cell: They are responsible for producing ATP (adenosine triphosphate), the primary energy currency of the cell.
* Metabolically active cells require more energy: Cells that engage in processes like muscle contraction, nerve impulse transmission, and protein synthesis need a constant supply of ATP.
* More mitochondria = more ATP production: Cells with high energy demands have more mitochondria to meet their energy needs.
Examples of cells with high numbers of mitochondria:
* Muscle cells: Muscle cells need lots of energy for contraction.
* Nerve cells: Nerve cells need energy for transmitting signals.
* Liver cells: Liver cells perform many metabolic processes.
* Sperm cells: Sperm cells require energy for their movement.
