Cattle or goats are never seen browsing on $Calotropis$ growing in abandoned fields because of the presence of:

If the strong partner is benefitted and the weak partner is damaged,it is known as

Discuss the various types of positive interactions between species.

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

Name the association in which one species produces a poisonous substance or a change in environmental conditions that is harmful to another species.

While living in and on the host species, the animal parasite has evolved certain adaptations. Describe these adaptations with examples.