Explain: $(a)$ Homology $(b)$ Analogy.

(N/A) Comparative anatomy and morphology show similarities and differences between organisms of today and those that existed years ago. These similarities help determine whether current organisms descended from common ancestors.
$(a)$ Homology: Whales,bats,cheetahs,and humans (all mammals) share similarities in the pattern of bones of their forelimbs. Although these forelimbs perform different functions in these animals,they have similar anatomical structures. In all of them,the forelimbs consist of humerus,radius,ulna,carpals,metacarpals,and phalanges. This is an example of divergent evolution,and these structures are called homologous organs. Homology indicates common ancestry.
$(b)$ Analogy: This refers to structures that perform similar functions but have different anatomical origins. This is a result of convergent evolution,where different groups of organisms adapt to similar habitats by developing similar adaptations for similar functions. Examples include the eyes of an octopus and mammals,or the flippers of penguins and dolphins. Another example is the sweet potato (root modification) and potato (stem modification),which are analogous organs.