Pond silk' is the common name of

Options

A. Corallina
B. Spirogyra
C. Selaginella
D. Chlorella.

Answer

To determine the common name of 'Pond silk', we will analyze the options provided and identify the correct answer step by step.

### Step 1: Understand the term 'Pond silk'
- 'Pond silk' refers to a type of algae that is commonly found in freshwater environments. It is known for its filamentous structure and the way it appears on the surface of ponds.

### Step 2: Analyze the options
- A. Corallina: This is a type of red algae, typically found in marine environments, not freshwater.
- B. Spirogyra: This is a filamentous green algae that is commonly found in freshwater ponds and is known for its silky appearance.
- C. Silaginella: This refers to a genus of plants known as clubmosses, which are not algae and do not fit the description of 'Pond silk'.
- D. Cholera: This is not related to algae; it refers to a disease caused by bacteria.

### Step 3: Identify the characteristics of Spirogyra
- Spirogyra is known for its long, green filaments that float on the surface of water bodies. It secretes mucilage, which gives it a shiny, slimy texture, resembling silk.

### Step 4: Conclusion
- Based on the analysis, the common name 'Pond silk' corresponds to Spirogyra due to its filamentous structure and the mucilage it secretes.

### Final Answer
The common name of 'Pond silk' is **B. Spirogyra**.

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