Which of the following classifications includes both terrestrial and aquatic species?

The classification that includes both terrestrial and aquatic species is the Kingdom Chordata. This kingdom encompasses a diverse range of organisms known as chordates, which are characterized by the presence of a notochord, a dorsal nerve cord, and pharyngeal slits at some stage in their development.

Chordates include vertebrates like mammals, birds, reptiles, amphibians, and fish. Mammals and birds are primarily terrestrial, whereas many species of fish and amphibians are aquatic, demonstrating the kingdom's diversity in habitat. For instance, vertebrates such as frogs and certain reptiles (like turtles) can be found both on land and in water, thus showcasing the ability to thrive in both environments.

In contrast, the other kingdoms mentioned are primarily limited to either terrestrial or aquatic environments, or are not as broadly inclusive of both categories. For example, Plantae includes terrestrial plants and some water plants, but many higher plants are specifically adapted to land environments. Similarly, Kingdom Fungi predominantly consists of terrestrial organisms, while Monera includes single-celled organisms, which are often aquatic but lack the complexity and diversity found in Chordata. Therefore, Kingdom Chordata is the correct choice as it includes species that are adapted to both terrestrial and