The organ that destroys old red blood cells and stores white blood cells is the spleen.

Here's a breakdown of its functions:

* Destroying old red blood cells: The spleen contains specialized cells called macrophages that engulf and break down worn-out red blood cells. This process is called hemolysis.

* Storing white blood cells: The spleen acts as a reservoir for white blood cells, particularly lymphocytes and monocytes. These cells are released into the bloodstream when needed to fight infections.

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