The statements the describe the ecosystems are the following:
1. Balance is required for the survival of an ecosystem.
2. One way to determine an ecosystem's health is by its biodiversity. Biodiversity means having different kinds of plants and animals in an ecosystem.
3. Predators play a role in balancing the earth's ecosystems. These animals are essential in maintaining the food pyramid or the food chain.
Well maybe if this was a question i could answer it.
Answer: It is the principle of Geology that states the geologic feature which cuts another is younger of the two features.
Explanation: It is used to determine the relative ages of rock strata and other geological structures.