1. Ecology
The study of the interrelationships between organisms and their natural environment, both living and non-living.

2. Ecosystem
A biological community and the physical environment associated with it.

3. The place in which an organism lives.
Habitat
The place in which an organism lives.

4. All of the living organisms living in a particular area or habitat.
Community
All of the living organisms living in a particular area or habitat.

5. Population
A group of individuals of the same species, living in a particular area at a particular time.

6. The source of energy for nearly all life on Earth is the Sun.
Energy in an
Ecosystem
The source of energy for nearly all life on Earth is the Sun.
Plants transfer light energy from sunlight into chemical energy in food. This process is called photosynthesis.

7. Trophic levels = feeding levels
Plants produce the food for the rest of the community, so they are called producers.

8. Animals eat or consume this food, so they are consumers.
An animal which eats a plant – a herbivore – is a primary consumer.
An animal which eats a primary consumer is a secondary consumer, and so on.
An animal which regularly eats both plants and animals is an omnivore.

9. Organisms which feed by breaking down dead bodies or waste material are called decomposers.