An association between rots of higher plants and fungi is called, 1. lichen, 2. fern. 3. mycorrhiza. 4.BGA

Options

A. lichen
B. fern
C. mycorrhiza
D. BGA.

Explanation

To solve the question, we need to identify the correct term that describes the association between the roots of higher plants and fungi. Let's break down the options provided:

1. **Lichen**: This is a symbiotic relationship between fungi and algae (or cyanobacteria), not specifically between fungi and the roots of higher plants.

2. **Fern**: Ferns are a type of vascular plant that belong to the kingdom Pteridophyta. They do not describe a relationship between roots and fungi.

3. **Mycorrhiza**: This is a specific association between the roots of higher plants and fungi. In this relationship, the plant benefits from enhanced nutrient and water absorption, while the fungus receives carbohydrates and other organic substances from the plant.

4. **BGA (Blue Green Algae)**: This refers to cyanobacteria, which are photosynthetic organisms. They do not form a direct association with the roots of higher plants in the same way that mycorrhiza does.

Based on this analysis, the correct answer to the question is **3. mycorrhiza**.

### Step-by-Step Solution:
1. **Understand the question**: Identify the type of association being asked about.
2. **Analyze each option**:
- Lichen: Association between fungi and algae, not roots of higher plants.
- Fern: A type of plant, not an association.
- Mycorrhiza: A symbiotic relationship between roots of higher plants and fungi.
- BGA: Refers to cyanobacteria, not a direct association with plant roots.
3. **Select the correct answer**: Based on the analysis, the correct answer is mycorrhiza.