AP BIOLOGY

Detailed explanation-1: -Homologous structures are similar physical features in organisms that share a common ancestor, but the features serve completely different functions. An example of homologous structures are the limbs of humans, cats, whales, and bats.

Detailed explanation-2: -These likenesses in structure, called homologies, are the result of descent from a common ancestor. In related species, the same anatomical features evolved into distinct forms as they were used in different environments or for different functions.

Detailed explanation-3: -Now let’s look at analogous structures. Analogous structures have different morphology, which means they are different in structure but have similar function. Let’s take our bat wing again, and this time compare it to a butterfly wing and a bird wing.

Detailed explanation-4: -When two or more organs or structures are basically similar to each other in construction but are modified to perform different functions, they are said to be serially homologous. An example of this is a bat’s wing and a whale’s flipper.

Detailed explanation-5: -We call anatomically similar body parts homologous structures. Note that homologous structures don’t have to have the same function. For example, a human arm and a whale flipper are used for completely different purposes but are made of very similar bones. They are homologous to each other.