As animals moved on land, they developed four limbs. In animals that moved away from water, such as reptiles . birds, and mammals, a membrane called the amnion protects the embryo in the egg from drying out. The development of four limbs is an example of a(n) square homology., whereas the presence of the amnion is an example of a(n) square v homology.

The development of four limbs is an example of a(n) **analogous** homology, whereas the presence of the amnion is an example of a(n) **homologous** homology.<br /><br />**Explanation:**<br /><br />1. **Analogous Homology:**<br /> - Analogous homology refers to structures that perform a similar function but do not share a common ancestral origin. The development of four limbs in different groups of animals (e.g., tetrapods) is an example of analogous homology because these limbs serve a similar function (locomotion) but evolved independently in different lineages.<br /><br />2. **Homologous Homology:**<br /> - Homologous homology refers to structures that share a common ancestral origin and may or may not perform the same function. The presence of the amnion in reptiles, birds, and mammals is an example of homologous homology because the amnion is a feature that evolved once in a common ancestor and was inherited by these different groups, even though it may serve slightly different functions in each group (e.g., protecting the embryo in the egg in reptiles and birds, and providing a fluid-filled environment in mammals).