Define the following terms and give two examples in each case.
(a) Symbiosis
Symbiosis is the interaction in which both the interacting species are benefited.
Example:
Plants need the help of animals for pollinating their flowers and dispersing their seeds. Animals in return get fruits and nectar from plants.
Lichens provide an example of symbiosis in which a fungus and a photosynthetic alga live in a symbiotic relationship.