Match List-I with List-II

'-' sign for detrimental interaction, '0' sign for neutral interaction, '+' sign for beneficial interaction

Choose the correct answer from the options given below:

(A)-(II), (B)-(IV), (C)-(I), (D)-(III)

The correct answer is Option (4) → (A)-(II), (B)-(IV), (C)-(I), (D)-(III)

A. Mutualism: This interaction confers benefits on both the interacting species. Lichens represent an intimate mutualistic relationship between a fungus and photosynthesising algae or cyanobacteria. Similarly, the mycorrhizae are associations between fungi and the roots of higher plants. The fungi help the plant in the absorption of essential nutrients from the soil while the plant in turn provides the fungi with energy-yielding carbohydrates.

B. Competition is best defined as a process in which the fitness of one species (measured in terms of its ‘r’ the intrinsic rate of increase) is significantly lower in the presence of another species. It is relatively easy to demonstrate in laboratory experiments, as Gause and other experimental ecologists did, when resources are limited the competitively superior species will eventually eliminate the other species, but evidence for such competitive exclusion occurring in nature is not always conclusive.  Connell’s elegant field experiments showed that on the rocky sea coasts of Scotland, the larger and competitively superior barnacle Balanus dominates the intertidal area, and excludes the smaller barnacle Chathamalus from that zone.

C. Commensalism refers to an interaction between species where one species benefits while the other is neither harmed nor benefited.
For  example an orchid growing as an epiphyte on a mango branch and barnacles growing on the back of a whale both derive benefits, while the mango tree and the whale do not appear to be affected positively or negatively.

D. In amensalism, one species is harmed whereas the other is unaffected.