Apex predator- in ecology, any flesh-eating animal that has no natural predators or enemies. Apex predators hold the top rank in a plant-herbivore-carnivore food chain and the uppermost position of an ecosystem’s trophic (or energy) pyramid, making them the final destination of energy flow in a given biological community.
Obligate mutualism- the species are entirely dependent on each other and in others
Facultative mutualism- they derive benefits from their relationship but could survive without each other
Mutualism:
Root nodules of a legume with N-fixing bacteria - facultative
Termites & gut flagellates - obligate
Lichens are close association between fungus and algae - obligate
A hummingbird looks for nectar and pollen from the flower - obligate
A green anole, native to southwestern US, and the brown anole, an introduced species from Cuba, vie for habitat and food sources. Brown anole has displaced green anole in areas like lower shrubbery and grass; while the green anole has lived up in trees and foliage. The result of competition is known as resource partitioning.
Herbivory: A special case of predation in which the prey species is a plant
Symbiosis: Interspecific interaction in which two species live together in a long-term, intimate association
Competition: A lion and a hyena fighting over a carcass; regardless of "winner," both expend energy and risk being injured.
Mutualism: A penstemon and the bee that pollinates it; the penstemon spreads its genes and the bee gets food.
Predation or Parasitism: A fungus growing on a wild rosebush; the fungus gains energy while the rose experiences it as a disease.
Commensalism: An orchid growing on a tree; the orchid has a support structure that protects it and makes it more accessible to pollinators, with no impact on the tree.
Amensalism: A sunflower struggles to grow in the shade of a walnut tree; the tree experiences no impact from the presence of the sunflower.
Neutralism: Two species of insects live on the same plant in close proximity but because they use different parts of the plant, they have no effect on each other.