Aperson breaks a bone and has it set and put in a cast, but it does not heal. what would be the best thing for the doctor to investigate as a possible cause?

The doctor should investigate about the osteoblasts that should have been constructing the new bone.

Explanation:

The cells, which form bones by discharging the extracellular matrix for bone tissue are known as osteoblasts. These cells discharge the constituents like inorganic electrolytes and collagen fibers that together produce the matrix of the bone tissue. The inactivity or absence of these cells could inhibit the production of new bone post-fracture. Hence, doctors should investigate osteoblasts.

i would say the prokaryotic cells the prokaryotic cells are less complex, are usually found only in unicellular organisms and have more limited capabilities than eukaryotic cells.