Question

drag each label to the correct location. categorize the structures as homologous or analogous. homologous analogous the mammalian tail and the human coccyx (tail bone) differ in their functions, but the close resemblance of these structures indicates a common evolutionary origin. the function of shells in both turtles and crabs is protection, but the anatomy of their shells is different. the bills of ducks and platypuses have similar functions but differing structures. the flippers of both penguins and dolphins help them swim, but the internal structures of the flippers vary. the leaves of pitcher plants and the spines of cacti are derived from a common ancestral form, but these structures differ in their functions.

Explanation:

To solve this, we first recall the definitions:

• Homologous structures: Share a common evolutionary origin (but may have different functions).
• Analogous structures: Have similar functions (but different evolutionary origins).

Homologous (Common Ancestry, Different Functions)

1. The mammalian tail and the human coccyx...: Both have a common evolutionary origin (mammalian lineage) but different functions.
2. The leaves of pitcher plants and the spines of cacti...: Derived from a common ancestral form but differ in function (pitcher leaves for trapping, cactus spines for protection).

Analogous (Similar Function, Different Origins)

1. The bills of ducks and platypuses...: Similar function (feeding) but different evolutionary origins (ducks are birds, platypuses are mammals).
2. The function of shells in turtles and crabs...: Similar function (protection) but different shell anatomy (different evolutionary origins).
3. The flippers of penguins and dolphins...: Similar function (swimming) but different internal structures (penguins are birds, dolphins are mammals—different lineages).

Answer:

• Homologous:
• The mammalian tail and the human coccyx (tail bone) differ in their functions, but the close resemblance of these structures indicates a common evolutionary origin.
• The leaves of pitcher plants and the spines of cacti are derived from a common ancestral form, but these structures differ in their functions.

• Analogous:
• The bills of ducks and platypuses have similar functions but differing structures.
• The function of shells in both turtles and crabs is protection, but the anatomy of their shells is different.
• The flippers of both penguins and dolphins help them swim, but the internal structures of the flippers vary.