Read the passage and answer the following questions:
Mutualism is an interaction that benefits both species involved. One example of mutualism is the lichen, an intimate association between a fungus and photosynthesising algae or cyanobacteria, which rely on each other for survival. The fungus provides a protected environment and absorbs water and nutrients, while the photosynthetic partner conducts photosynthesis and produces energy-rich carbohydrates that benefit both organisms. Another example is mycorrhizae, where fungi form associations with the roots of higher plants. The fungi assist the plants in absorbing essential nutrients from the soil, such as phosphorus, in exchange for receiving energy-yielding carbohydrates produced by the plants through photosynthesis. In plant-animal relationships, mutualism is evident in the process of pollination and seed dispersal. Plants rely on animals, such as bees, butterflies, and birds, to transfer pollen between flowers, facilitating reproduction. In return, plants offer rewards to the pollinators, such as pollen and nectar, which serve as a source of food for the animals. Similarly, when animals consume fruits and disperse seeds through their excretion or by carrying them to new locations, they benefit from the nutritional value of the fruits, while the plants benefit from the dispersal of their seeds. Not all mutualistic interactions involve direct rewards. Some orchids, like the Mediterranean orchid Ophrys, employ "sexual deceit" to achieve pollination. One petal of the flower resembles the female bee in size, colour and markings, attracting male bees that attempt to mate with the flower. During this process, the bee gets covered in pollen, and when it visits another flower, it transfers the pollen, facilitating pollination.
A mutually beneficial plant–animal system has to be safeguarded against ‘cheaters’. Which of the following is an example of a cheater?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → An animal that steals nectar without aiding in pollination
In plant–animal mutualism, plants pay animals ‘fees’ for their services: pollen and nectar for pollinators, and juicy, nutritious fruits for seed dispersers. A cheater is an animal that takes the fee but gives no service in return.
Option (1) A bee that collects pollen and carries it to another flower of the same species — Incorrect. A bee that takes pollen and carries it to another flower of the same species does pollinate. It takes the reward and gives the service, so it is a true mutualist.
Option (2) An animal that steals nectar without aiding in pollination — Correct. An animal that steals nectar without aiding in pollination takes the reward and gives nothing back. The book names such animals as the cheaters the system must be safeguarded against.
Option (3) A bird that eats juicy fruits and disperses their seeds — Incorrect. A fruit-eating bird disperses the seeds, which is the service the plant pays for with its fruit. It is a seed disperser, not a cheater.
Option (4) An insect that feeds on the leaves and sap of the plant — Incorrect. An insect feeding on leaves and sap is an herbivore; for the plant, it is a predator. It takes no part in pollination or seed dispersal, so it is not a cheater within the mutualism.
NCERT Extract:
Population Interactions – “… Animals obviously have to be paid ‘fees’ for the services that plants expect from them. Plants offer rewards or fees in the form of pollen and nectar for pollinators and juicy and nutritious fruits for seed dispersers. But the mutually beneficial system should also be safeguarded against ‘cheaters’, for example, animals that try to steal nectar without aiding in pollination.”