Internal tubes through which air is taken for respiration. Vertebrates with lungs have a single trachea carrying air to the lungs, while insects and some other land-living arthropods have a complex ...
A group of cells with a specific function in the body of an organism. Lung tissue, vascular tissues, and muscle tissue are all kinds of tissues found in some animals. Tissues are usually composed of ...
An animal with four limbs that evolved from a common fish ancestor during the Devonian Period (~365 million years ago). Tetrapods include amphibians, reptiles, birds, and mammals. Though "tetrapod" ...