Plants and animals live on all parts of the earth. Each organism lives where conditions are the most suitable for its own specific needs. Organisms within an area interact with one another and also with their environment.

Interactions among organisms strongly influence the behavior and ecology of organisms. The interactions are defined as whether they are beneficial, harmful or neutral.

Mutualistic relationships are interactions which invokes both plant and animal are benefiting. Mutualism is very common in pollination. Antagonistic interactions are usually harmful



Life on the earth is limited to a very narrow zone called the biosphere. Organisms live within the biosphere. The part of the biosphere that surrounds an organism is called its environment.Organisms interact and form complete relationships within an environment. The study of the interactions between organisms and their environments is called ecology. Living organisms interacting with each other and their nonliving environment make up an ecosystem. An ecosystem contains one or more communities of living organisms.

A community is all the organisms living together in a certain area. Each community has species of animals, plants and other organisms that live together.All the organisms of one species in a community are called a population. To describe a community you need to know the kinds of populations that are present. You need to know the size of the population. Any one community may contain hundreds of different populations.

Within a community , each species has a niche. A niche is the function or role of an organism's interactions with all other parts of its environment. What an organism eats and how it obtains food are part of its niche. How it interacts with other organisms is part of its niche One example of a niche is a forest floor community. When a termite eats the wood of a fallen tree, the tree is the termite's habitat. The termite's niche within the community of the tree its breaking down of one part of the dead tree. Other organisms within the community, such as lichens, mosses, fungi, beetles, and other insects, may also break down dead matter of the tree.

 Competition is the contest among organisms to obtain all the requirements for life, within a niche. Individuals within a species may compete with each other, especially for food, living space and mates. The individuals within species that survive are those best adapted to current conditions in the ecosystem. For example giraffes with longer necks might be better adapted to conditions during which all the lower branches of food trees have been stripped bare.

Animals of the same species or different species may form cooperate relationships. A close association of two or more species is called symbiosis. The three types of symbiotic relationship are mutualism,commensalism, and parasitism.

Mutualism - a relationship in which both species benefit. Pea crabs that live inside mussel shells is an example of mutualism. Pea crabs eat the young of organisms that would harm the mussels if they grew to adults to adults inside the shell. In return, the mussels provide protection for the crabs.Some fungi and plants have a mutualistic relationship. From 70-100 percent of all trees, grasses, shrubs, and flowers in any area grow well thanks to the fungi that grow on their roots.

Commensalism- is a relationship in which one organism benefits and the other neither benefits nor is harmed. Some plants such as Spanish moss, orchids, and staghorn ferns grow high up in trees. These plants also have a relationship with the trees on which they grow. The host provides a safe growing place for the plants. At the same time, the plants get nutrients from rain water and don't harm the host.

The remora fish, a weak swimmer, attaches itself to sharks and feeds on their left overs. In a similar way, vultures follow lions and other predators and feed after they leave.

Parasitism- relationship where one of the species harms or kills the other one.Many species of animals and plants, such as ticks, lice, tapeworms, and heart worms, feed on other animals and plants. Parasites feed on their hosts, slowly weakening them. Usually a parasite does not kill the organism it feeds on, but it does kill the organism it feeds on, but it does cause the host organism harm. In addition mosquitoes and other blood-sucking parasites can give their hosts serious diseases, such as malaria.