What is an example of mutualism?

Lichens consisting of fungi and algae.

The correct answer is Option (1) -Lichens consisting of fungi and algae.

Lichens represent an example of mutualism, which is an intimate and beneficial association between a fungus and photosynthetic organisms like algae or cyanobacteria. In lichens, the fungus provides a protective environment and absorbs water and nutrients from the surroundings. Meanwhile, the photosynthetic partner (algae or cyanobacteria) conducts photosynthesis and produces organic compounds, which are utilized by both organisms.

The fungi in lichens provide a suitable habitat for the algae or cyanobacteria to grow and thrive. In return, the photosynthetic partners supply the fungi with energy-yielding carbohydrates through photosynthesis. This mutualistic relationship allows lichens to colonize various habitats, including rocks, trees, and soil, where they play important ecological roles, such as soil stabilization and nutrient cycling.

The other options, such as cattle egret foraging near grazing cattle, barnacles growing on the back of a whale, and orchid growing as an epiphyte on a mango branch, do not represent mutualism. These interactions may fall under different categories, such as commensalism (cattle egret and grazing cattle),(barnacles and whale), (orchids growing as an epiphyte on a mango branch) where one species benefits without harming or benefiting the other species.