ANATOMY

Detailed explanation-1: -Homologous structures provide evidence for common ancestry, while analogous structures show that similar selective pressures can produce similar adaptations (beneficial features). Similarities and differences among biological molecules (e.g., in the DNA sequence of genes) can be used to determine species’ relatedness.

Detailed explanation-2: -If two or more species share a unique physical feature, such as a complex bone structure or a body plan, they may all have inherited this feature from a common ancestor. Physical features shared due to evolutionary history (a common ancestor) are said to be homologous.

Detailed explanation-3: -The flippers in whales and the wings in the birds are referred to as homologous because these organs have arisen through divergent evolution. These organisms, therefore, have a common ancestor.

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.