Which of the following pairs is correctly matched?

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

Identify Gause's Competitive Exclusion Principle from the following.

Which of the following represents the correct population interaction?

In which of the following interactions are both organisms negatively affected?

Study the following four statements $(1-4)$ and select the two which are correct:
$(1)$ Lion eating deer and sparrow feeding on grain are ecologically similar in being consumers.
$(2)$ The predator starfish $Pisaster$ helps in maintaining species diversity of some invertebrates.
$(3)$ Predators often lead to the extinction of prey species.
$(4)$ Production of chemicals such as nicotine and strychnine by plants is a metabolic disorder.
Which two statements are correct?