1. all living organisms in an ecosystem.
2. the number of species living within an ecosystem.
3. the study of a habitat's abiotic and biotic factors.
4. the portion of the planet that contains life.
5. alligators, turtles, and fish living together in a river
form this.
6. soil, water and weather.
7. an ecological system that scientist often study.
8. a place where a population lives.
9. all of the species of freshwater fish that live together
in a lake form this.
10. consists of a community and abiotic factors.

An ecosystem is commonly referred to as harmonious combinations of all living and non living things in a particular area or community.

Explanation:

All living organisms in an ecosystem forms the biotic component of the said ecosystem.Biodiversity is correct term to denote the number of species living in an ecosystem.The study of a habitat's abiotic and biotic factors is known as ecology.Biosphere comprises of the portion of the planet that contains life.Alligators, turtles, and fish living together in a river forms the river community.Soil, water and weather forms the abiotic components.The study of an ecological system by a scientist is known as ecosystem and the subject of study is often referred to as ecology.The place where a population thrive is commonly referred to as habitat.All of the species of freshwater fish that lives together in a lake forms the freshwater ecosystems.Ecosystems consists of a community and abiotic factors.

The right answer is c.sandstone.