Biology · Organisms and Populations · NEET
Predation is (+, −): the predator gains (+) and the prey is harmed (−). It is NOT (−, −). A (−, −) interaction where BOTH species lose is competition, not predation. In predation only one species is negatively impacted (the prey), so any statement saying 'both species are harmed' is describing competition, not predation. This exact confusion was tested in NEET 2022.
In the broad ecological sense, predation just means one organism eating another living organism to gain energy. NCERT says a sparrow eating a seed is 'no less a predator', and for plants, herbivores ARE the predators. So predation covers carnivores eating animals AND herbivores eating plants. Herbivores are categorised separately by name, but ecologically they act like predators, transferring plant energy to higher trophic levels.
Both share the (+, −) sign, so signs alone cannot separate them — that is the trap. The difference is how the prey/host is used: a predator usually kills and eats the prey quickly, while a parasite lives on or inside the host, feeds on it over time and usually does NOT kill it immediately. If a NEET option lists both Predation and Parasitism as (+,−), read the OTHER options to decide which one the examiner wants.
Four roles from NCERT: (1) They act as 'conduits' for energy transfer to higher trophic levels. (2) They keep prey populations under control, preventing overpopulation and ecosystem instability. (3) They maintain species diversity by reducing competition among prey — proven by the starfish Pisaster experiment on the American Pacific coast, where removing the starfish caused over 10 invertebrate species to go extinct. (4) They help control invasive species (e.g. a moth controlled the prickly pear cactus in Australia).
NCERT says predators are 'prudent' because if a predator is too efficient and overexploits its prey, the prey may become extinct — and then the predator also goes extinct due to lack of food. So natural predators do not wipe out their prey; they keep prey numbers in balance. 'Prudent' here means cautious/wise, not that predators consciously plan it.
Which one of the following statements cannot be connected to Predation?
Match List-I (A. Both species are harmed, B. One species is harmed and the other is benefited, C. Both species are benefited, D. One is benefited while the other has no effect) with List-II (I. Predation, II. Mutualism, III. Competition, IV. Commensalism).
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Predation is a (+, −) population interaction in which the predator benefits by eating the prey, which is harmed.
Yes, in the broad ecological sense. NCERT says herbivores are the 'predators' of plants, and even a sparrow eating a seed acts as a predator, because both transfer plant energy to higher trophic levels.
The starfish Pisaster experiment on the American Pacific coast: when all starfish (the predator) were removed from an intertidal area, more than 10 invertebrate species went extinct within a year due to competition.
A cactus-feeding moth introduced from the cactus's natural habitat. This is a classic NCERT example of biological control using a predator.
Yes, both are (+, −). Signs alone cannot separate them; the difference is that a predator kills and eats the prey, while a parasite lives on/in the host and usually does not kill it at once.
