Which of the following associations is not an example of symbiosis?

Options

A. Lichen
B. Mycorhiza
C. Root nodules
D. Epiphytes

Answer

To determine which of the following associations is not an example of symbiosis, let's analyze each option:

1. **Lichen**: This is a symbiotic relationship between fungi and algae. The fungi provide structure and protection, while the algae perform photosynthesis to produce food. Thus, lichen is an example of symbiosis.

2. **Mycorrhizae**: This refers to the symbiotic association between the roots of higher plants and fungi. The fungi enhance water and nutrient absorption for the plant, while the plant provides carbohydrates to the fungi. Therefore, mycorrhizae is also an example of symbiosis.

3. **Root Nodules**: These are formed by the symbiotic relationship between leguminous plants and nitrogen-fixing bacteria. The bacteria convert atmospheric nitrogen into a form usable by plants, while the plants provide nutrients to the bacteria. Hence, root nodules represent another example of symbiosis.

4. **Epiphytes**: Epiphytes are plants that grow on the surface of other plants (like trees) but do not derive nutrients from them. Instead, they obtain moisture and nutrients from the air, rain, and debris. Since epiphytes do not have a mutualistic relationship with the host plant, they are not considered an example of symbiosis.

Based on this analysis, the correct answer is **option D: epiphytes**, as it is not an example of symbiosis.