What do we call the extensive growth of algae in a lake?

Options

A. Symbiosis
B. Competition
C. Algal bloom
D. Humus

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term that describes the extensive growth of algae in a lake.

2. **Identifying Key Terms**: The options provided are:
- Symbiosis
- Competition
- Algal Bloom
- Humus

3. **Analyzing Each Option**:
- **Symbiosis**: This refers to a relationship between two different organisms where they live together and benefit from each other. This does not relate to algae growth.
- **Competition**: This refers to the struggle between organisms for the same resources, such as food or space. This also does not describe algae growth.
- **Algal Bloom**: This term specifically refers to the rapid increase or accumulation of algae in water bodies, often due to high nutrient levels.
- **Humus**: This is a dark organic material in soil, formed by the decomposition of plant and animal matter. It is not related to algae growth.

4. **Selecting the Correct Answer**: Based on the analysis, the term that accurately describes the extensive growth of algae in a lake is **Algal Bloom**.

5. **Understanding the Consequences**: When algae bloom, they can deplete oxygen in the water as they die and are decomposed by microorganisms, leading to negative impacts on aquatic life, such as fish mortality.

**Final Answer**: The extensive growth of algae in a lake is called **Algal Bloom**.

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