ANATOMY

Detailed explanation-1: -Homologous structures show individual variations on a common anatomical theme. These are seen in organisms that are closely related. Analogous structures have very different anatomies but similar functions.

Detailed explanation-2: -Comparison to Human Arm in Function Whale Whale has a much shorter and thicker humerus, radius, and ulna. Much longer metacarpals. Thumb has been shortened to a stub. The whale fin needs to be longer to help in movement through water.

Detailed explanation-3: -Homologous structures share a similar embryonic origin; analogous organs have a similar function. For example, the bones in the front flipper of a whale are homologous to the bones in the human arm. These structures are not analogous. The wings of a butterfly and the wings of a bird are analogous but not homologous.

Detailed explanation-4: -Correct answer: Explanation: When parts of an animal serve different functions but have similar placement and bone structure (such as a wolf forearm and a whale flipper) and are derived from a common ancestor, these two structures are homologous.

Detailed explanation-5: -Explain the evolutionary relationship between the fin of a fish and the flipper of a whale. The fin of a fish and the filpper of a whale are analogous structures. They have the same job ( function) but different internal structures. This suggests that the DO NOT share a recent common ancestor.