a. Commensalism: In ecology, commensalisms is a class of relationship between two organisms where one organism benefits but the other is unaffected.
b. Parasitism: It is a relationship between two organisms where the larger animal is at harm and the smaller animal is benefited.
c. Camouflage: Camouflage is a method of crypsis avoidance of observation - that allows an otherwise visible organism or object to remain indiscernible from the surrounding environment through deception. The best example of camouflage is shown by the garden lizard which changes its colour as per its surroundings.
d. Mutualism: It is relationship between two organisms where both organisms are benefited. For example, some birds pick worms and insects from big animals skin to get food. This helps the bigger animal to get rid of insects and worms.
e. Interspecific competition: Interspecific competion, in ecology, is a form of competition in which individuals of different species compete for the same resource in an ecosystem (e.g. food or living space).