If $'+'$ sign is assigned to beneficial interaction,$'-'$ sign to detrimental and $'O'$ sign to neutral interaction,then the population interaction represented by $'+, -'$ refers to

Carnivorous animals, such as lions and leopards, occupy the same niche, but lions predate mostly on larger animals while leopards take smaller ones. This mechanism of competition is referred to as:

$A$ cuckoo laying eggs in the nest of other species of birds is an example of

Lianas are vascular plants rooted in the ground and maintain erectness of their stem by making use of other trees for support. They do not maintain direct physiological relation with those trees. Discuss the type of association the lianas have with the trees.

The association of a sea anemone living on the shell of a hermit crab is known as:

The principle of competitive exclusion was stated by