A seral community (or sere) is an intermediate stage found in ecological succession in an ecosystem advancing towards its climax community.

In this, both the partners get benefited. Lichen is a composite organism consisting of a fungus (the mycobiont) and a photosynthetic partner (phycobiont) growing together in a symbiotic relationship.

Mycoplasma refers to a genus of bacteria that lack a cell wall. An obligate parasite is a parasitic organism that cannot complete its life cycle without exploiting a suitable host.

It is an association between organisms in which one benefits at the expense of the other.

An organism in a symbiotic relationship is called a symbiont.

In negative interaction, both the partners are mutually inhibited.

It is a particular form of competition in which members of the same species vie for the same resource in an ecosystem.

Plants that grow in shade are called sciophytes.

An herbivore is an animal that gets its energy from eating plants, and only plants. Plant parasites are classified as herbivores because these feed on plants.

It is where two species interact with each other beneficially without establishing a physical contact with each other. The rhizosphere is the zone surrounding the roots of plants in which complex relations exist among the plant, the soil microorganisms and the soil itself.

Decomposers or saprotrophs are organisms that break down dead or decaying organisms, and in doing so carry out the natural process of decomposition.

Predators are also called as live feeders as they feed directly upon their prey.

Ecesis refers to proper establishment of migrants at the new site, which includes seed germination and their colonisation.

In competition, both the species are harmed due to the limited supply of resources. Hence, this interaction is completely negative for both the members.

It is a class of relationship between two organisms where one organism benefits without affecting the other.