AP BIOLOGY

Detailed explanation-1: -Amphibians. The amphibian kidney also functions chiefly as a device for excreting excess water. The permeable skin of the frog provides an easy route for the fresh water of its pond to enter by osmosis. But, as their name suggests, amphibians also spend time on land.

Detailed explanation-2: -All vertebrates have kidneys. The kidneys are the main organ that allows species to adapt to different environments, including fresh and salt water, terrestrial life and desert climate. Depending on the environment in which animals have evolved, the functions and structure of the kidneys may differ.

Detailed explanation-3: -Terrestrial animals are animals that live predominantly or entirely on land, as compared with aquatic animals, which live predominantly or entirely in the water, or amphibians, which rely on a combination of aquatic and terrestrial habitats.

Detailed explanation-4: -And some animals still only have one kidney. Around 500 million years ago, our long-lost relatives that were living in the ocean (some of whom probably only had one kidney) decided to leave the water to walk and live on land.