Question: 138: While explaining interspecific interaction of population, (+) sign is assigned for beneficial interaction, (-) sign is assigned for detrimental interaction and ( 0 ) for neutral interaction. Which of the following interactions can be assigned ( + ) for one specifies and ( – ) for another specifies involved in the interaction ?
(1) Commensalism
(2) Competition
(3) Predation
(4) Amensalim
Answer: Option (3)
Explanation:
In predation, one species called the predator benefits by obtaining food,
so it is assigned a positive sign +.
The other species, called the prey, is harmed or killed during this interaction,
so it is assigned a negative sign -.
Thus, predation is an interaction of the type +/-.
In commensalism, one species benefits while the other is neither harmed nor benefited,
so it is +/0.
In competition, both species are negatively affected due to sharing of limited resources,
so it is -/-.
In amensalism, one species is harmed while the other is unaffected,
so it is -/0.
Therefore, the interaction that can be assigned + for one species
and - for the other is predation.