1. Feeding Relationships

2. Symbiosis
In an ecosystem, there are different relationships between organisms. Animals can work together in which they both benefit or one animal can steal the spoils of one animal’s hunt.
In an ecosystem / nature, there are three main symbiotic relationships.

3. There are Three Symbiotic Relationships
Mutualism- both organisms benefit from the relationship. Examples include
pollination of plants
bacteria and humans-  some bacteria lives in the intestines of humans. Humans cannot digest all of the food that we eat. The bacteria eats the food that the we cannot digest and partially digests it, allowing us to finish the job. The bacteria benefit by getting food, and we benefit by being able to digest the food we eat.
Oxpeckers and Zebras- An oxpecker is a type of bird that land on zebras and eat ticks. It also warns the zebras of danger. The bird gets food and the zebra gets pest control.

4. Commensalism
This is where only one organism benefits from the relationship but the other is unharmed. Examples include:
The remora fish and sharks. The fish sticks to the backs of sharks and get “free” transport around as well as it eats any left over food from the sharks.
Egrets and cattle- the cattle’s movements stur up a lot of bugs, insects and flies. These are prime food for the egret which lands on the backs of the cattle.

5. Parasitism
This is where one organism (parasite) benefits in the relationships while the other (the host) suffers.
As the name suggests, parasites are main culprits of this type of relationship.
Refer to this site for additional info.

6. Environment and Human Activities
Physical and biotic factors- Physical environment is also known as the Abiotic environment. It simply means all of the non-living chemical or physical properties in an eco-system. These would include air, water, the type of environment, soil type, etc.
Biotic factors- These include all of the living organisms in an ecosystem. Biotic factors are dependant on the Abiotic Factors.

7. Continuation
Environment and habitats- A habitat is a defined place or area of the environment.
The environment is everything around us.
Therefore a habitat is always an environment but an environment is not always a habitat.
A habitat always has life in it while the environment does not always have life.
A habitat is always a preference of one species, whereas an environment could be a preference of many species that could eventually become many habitats.
The environment affects the properties of a habitat but a habitat cannot affect the properties of the environment.

8. Continuation
Community and Population- A community is the total populations of different species.
Population is the total individuals of one specie that live in the same habitat.