Wings of birds and bats are considered analogous structures because they have

The correct answer is B, different origin and common function. Analogous structures do the same job but evolved separately, and the wings of birds and bats are a standard example. Both wings are used for flight, but the wing of a bird is made of feathers carried on the arm, while the wing of a bat is a thin membrane of skin stretched over very long finger bones. Birds and bats did not inherit their wings from a common winged ancestor; flight evolved in each group on its own. This process, in which unrelated groups develop similar features for a similar way of life, is called convergent evolution. The wings of insects and birds are another example. Option A is wrong because structures with a common origin and a common function are simply related organs, and this is not what analogy means. Option C is wrong because common origin with a different function defines homologous organs, such as a human arm, a whale's flipper and a cat's leg. Option D is wrong because structures with different origins and different functions are not compared at all. Exam tip: analogous, same function, different origin; homologous, same origin, different function.