The bean-shaped organ that maintains homeostasis in the body is the kidney.

Here's why:

* Homeostasis: This refers to the body's ability to maintain a stable internal environment despite external changes.

* Kidney's Role: Kidneys play a crucial role in homeostasis by:

* Filtering blood: They remove waste products, excess water, and electrolytes from the blood.

* Regulating blood pressure: They control the volume of blood by adjusting water and salt balance.

* Maintaining electrolyte balance: They ensure the proper levels of minerals like sodium, potassium, and calcium in the blood.

* Producing hormones: They secrete hormones like erythropoietin (stimulating red blood cell production) and renin (regulating blood pressure).

Let me know if you have any other questions!