What shape is typically associated with kidneys?

The shape typically associated with kidneys is bean-shaped. This characteristic form is seen in both human and many animal kidneys. The bean shape is not only an anatomical observation but also plays a role in the organ's function, allowing it to fit snugly within the abdominal cavity, while maximizing surface area for filtration and reabsorption processes. This unique shape contrasts with the other options, such as round, cylindrical, and square, which do not accurately represent the kidney's anatomy or function in the body. Understanding the shape of the kidneys is important for recognizing their placement and interactions with other organs within the urinary system.