Identify the incorrect statements from the following:
A. In commensalism, one species benefits while the other species is neither harmed nor benefited.
B. The interaction between a fungus and photosynthesising algae in lichens is an example of amensalism.
C. In parasitism, the host organism benefits from the relationship.
D. Barnacles growing on the back of a whale is an example of mutualism.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → B, C and D are incorrect.
A correct statement. A. In commensalism, one species benefits while the other species is neither harmed nor benefited. This is the definition of commensalism (+, 0), as with barnacles on a whale.
An incorrect statement. B. The interaction between a fungus and photosynthesising algae in lichens is an example of amensalism. In a lichen both partners gain, so it is mutualism (+, +). In amensalism one species is harmed and the other is unaffected.
An incorrect statement. C. In parasitism, the host organism benefits from the relationship. In parasitism only the parasite benefits. Most parasites harm the host, lowering its survival, growth and reproduction.
An incorrect statement. D. Barnacles growing on the back of a whale is an example of mutualism. The barnacles benefit, but the whale gets no apparent benefit. This is commensalism, not mutualism.
Statements B, C and D are incorrect.
NCERT Extract:
Population Interactions – “… Majority of the parasites harm the host; they may reduce the survival, growth and reproduction of the host and reduce its population density.”
Population Interactions – “… (iv) Commensalism: This is the interaction in which one species benefits and the other is neither harmed nor benefited. An orchid growing as an epiphyte on a mango branch, and barnacles growing on the back of a whale benefit while neither the mango tree nor the whale derives any apparent benefit.”
Population Interactions – “… (v) Mutualism: This interaction confers benefits on both the interacting species. Lichens represent an intimate mutualistic relationship between a fungus and photosynthesising algae or cyanobacteria.”