Here's an organized outline for AP Environmental Science Unit 2 reviews. This outline has been adapted from the 2019 Course Description published by College Board. You can use this to build an AP Enviro Unit 2 study guide.
The diversity of species and their habitats are vital to the survival of complex ecosystems.
The survival of organisms depends on their ability to adapt to disruptions to their environment.
Environmental changes place new pressures on organisms and they must be able to adapt by altering their behaviors or moving. These environmental changes can be sudden or gradual and threaten a species survival.
A keystone species is an organism that other species depend on and without it, the structure of the ecosystem would change.
An indicator species is a plant or animal, that can be used to infer conditions about the ecosystem by its presence or absence.