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

Which of the following is the correct reason for the extinction of Abingdon tortoises in the Galapagos Islands?

Which of the following plants produces a poisonous cardiac glycoside chemical?

Given below are two statements.
Statement $I$: $Calotropis$ growing in abandoned fields is never consumed by cattle and goats.
Statement $II$: $Calotropis$ produces highly poisonous cardiac glycosides.
In light of above statements,select the most appropriate answer from the option given below.

Commensalism can be represented 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