Answer:
This describes a species which makes up a large percentage of an ecosystem - Dominant species.
This is a species whose presence is critical to the integrity of the community. Without this species, the ecosystem may cease to exist - Keystone species.
This is a species that provides structure to a community by creating locally stable conditions for other species - Foundation species.
Any living organism which is "in danger of extinction throughout all or a significant portion of its range'' - endangered species.
Step-by-step explanation:
Foundation species have a strong role in shaping communities by creating and enhancing their habitats and provide locally stable conditions for other species. These species include primary producers, herbivores, predators, etc.
Keystone species are critical to the survival of the other species in the system and without them, the ecosystem may not survive. Examples include beavers, bees, mangrove trees, predators like wolves, sharks, etc.
Dominant species is the most abundant in the community (highest biomass) due to their compatibility and adaptability with the variables like climate and resources, and their proclivity toward procreation. The Kangaroo is a dominant species of the Australian savanna and the Huassai Palm is one of the dominant trees in the Amazon rainforest.
Endangered species consist of organisms that are very likely to become extinct in the near future. Examples include Asian elephant, Indus river dolphins, mountain gorilla, etc.