In 1831, Charles Darwin visited the Galapagos Islands While observing the giant land tortoises that lived on these islands, Darw
in noted that the shape of the tortoise shell varied depending on which island the tortoise lived. Tortoises on one island had round shells, for example, whereas tortoises on aneighboring island had more flattened, saddle-shaped shells. Which statement BEST summarizes Darwin's explanation for these differences? A) Random mutations caused the shape of the shells to fluctuate periodically. B) The shape of the tortoise shell varied because the predators on the islands were all similar. C) The particular shape of the shellwas best suited for the island on which the tortoise was living. D) Tortoises who used their shells in special ways caused the shells to become larger, rounder, or flatter.
Answer: The digestive system rids the body of the cells' waste and the excretory system fuels the cells. The digestive system does physical digestion while the excretory system carries out chemical digestion.
building proteins storing energy providing structure to cell walls carrying genetic information building proteins. storing energy. providing structure to cell walls.
