$A$ scorpion stalks,kills,and then eats a spider. Based on its behavior,which ecological terms describe the scorpion?

You never see any cattle or goat browsing on $Calotropis$ due to

Choose the correct group for commensalism from the following:
$(a)$ The cattle egret and grazing cattle
$(b)$ Barnacle balanus and Barnacle chathamalus
$(c)$ Goat and Abingdon turtle from Galapagos island
$(d)$ Barnacles growing on the back of whale

Why can the moth and the $Yucca$ plant not complete their life cycles without each other?

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

Whose field experiment showed that on the rocky sea coast,the larger and competitively superior barnacle excludes the smaller barnacle?