The interaction between two living organisms of different species which is beneficial to both but is not obligatory because they can live without each other is known as

Study the four statements $(i-iv)$ given below and select the two correct ones out of them.
$(i)$ $A$ lion eating a deer and a sparrow feeding on grains are ecologically similar in being consumers.
$(ii)$ Predator star fish $Pisaster$ helps in maintaining species diversity of some invertebrates.
$(iii)$ Predators ultimately lead to the extinction of prey species.
$(iv)$ Production of chemicals such as nicotine,strychnine by the plants are metabolic disorders.
The two correct statements are

In commensalism,

Which one of the following is $NOT$ an example of commensalism?

$Cuscuta$ is an example of

Given below are two statements:
Statement $I$: Gause's competitive exclusion principle states that two closely related species competing for different resources cannot exist indefinitely.
Statement $II$: According to Gause's principle,during competition,the inferior will be eliminated. This may be true if resources are limiting.
In the light of the above statements,choose the correct answer from the options given below :