Question

Refer to the given table that summarises the interactions between two organisms (organism 1 and organism 2 ). Identify the types of interaction $\left(\right.A,B\text{ and }C\left.\right)$ and select the correct answer.

(i) $A$ can be either predation or parasitism.
(ii) $B$ can be either commensalism or amensalism.
(iii) $Cc$ an be amensalism.
(iv) $A$ can be amensalism.

• A. (i) and (ii)
• B. (ii) and (iii)
• C. (iii) and (iv)
• D. (i) and (iii)

Answer 1

Answer: (D)

Amensalism: It is an interaction between two organisms of different species in which one species inhibits the growth of other species by secreting certain chemicals. The organism which inhibits the growth of another organism is called amensal. E.g. Penicillium secretes penicillin that inhibits the growth of a large number of bacteria. Such a population interaction is represented by (0,-).
In predation, only one species (predator) benefits and the interaction is detrimental to the other species (prey). It is a (+,-) type of population interaction.
Parasitism is a population interaction where one organism is benefited (parasite) while another organism (host) is harmed. It is (+,-) type of population interaction.
Commensalism is the interaction in which one species benefits and other is neither harmed nor benefited. The species which is benefited is termed commensal and the other species is called the host. Such a population interaction is represented by (+,0).