What is the function of the bones in bats that are homologous to finger bones in humans?

Explanation:

The flipper of a whale, the wing of a bat, and the leg of a cat are all very similar to the human arm, with a large upper "arm" bone (the humerus in humans) and a lower part made of two bones, a larger bone on one side (the radius in humans) and a smaller bone on the other side (the ulna).

answer; (phospholipid);