Bats and humans are both mammals and share a common ancestor. Because of this, a human arm and a bat wing have similar bone structure. In contrast, bird wings and bat wings have different structures. Explain these relationships in terms of homologous and analogous structures.

A great example of homologous structures are the wings of a bat and the arms of a human. Bats and humans are both mammals, so they share a common ancestry. Both a bat's wing and a human's arm share a similar internal bone structure, even though they look very different externally.

because of

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.