How do terrestrial animals prevent water loss while still exchanging gases and excreting wastes?

Terrestrial animals prevent water loss through adaptations such as waterproof skin and efficient kidneys.

Terrestrial animals face the challenge of conserving water while still exchanging gases and excreting wastes. One adaptation is waterproof skin, which reduces water loss through evaporation. For example, reptiles have scales that prevent water loss, while mammals have fur and sweat glands that help regulate body temperature and conserve water.

Another adaptation is efficient kidneys, which allow animals to excrete waste without losing too much water. Mammals have kidneys that filter blood and produce urine, while birds and reptiles have specialized structures called cloacas that allow them to excrete waste and reproduce without losing too much water. For more details on the structure of the kidney, refer to Structure of the Kidney.

In addition, some animals have evolved to extract water from their food. For example, desert animals such as camels and kangaroo rats can survive for long periods without drinking water by obtaining moisture from the food they eat. Understanding the active transport mechanism and its role can shed light on how these animals manage water balance efficiently.

Osmoregulation is another crucial aspect of water conservation. For more on this, see osmoregulators vs. osmoconformers.

A-Level Biology Tutor Summary: Terrestrial animals prevent water loss with waterproof skin, efficient kidneys, and extracting water from food. Reptiles have scales, and mammals have fur and sweat glands to reduce water loss. Efficient kidneys in mammals and cloacas in birds and reptiles help excrete waste without losing water. Desert animals like camels get moisture from their food.