I believe that a pair of homologous structures in this case is; Maple leaf and oak leaf. Homologous structures that have similar ancestries and common traits, however they may not have the same function in an organism. They appear in different animals or organisms, underlining anatomical commonalities demonstrating a descent from a common ancestor. Examples include the arm of a human, the wing of a bird or a bat, the leg of a dog and the flipper of a dolphin or whale.
