Why are potato and sweet potato called tubers ?

Explanation

**Step-by-Step Solution:**

1. **Definition of Tubers**: Tubers are specialized structures in plants that serve as storage organs. They are typically swollen and have a tube-like appearance.

2. **Types of Tubers**: There are two main types of tubers: modified stems and modified roots. In the case of potatoes, they are modified stems, while sweet potatoes are modified roots.

3. **Shape and Structure**: Both potato and sweet potato have irregular shapes, which is a characteristic feature of tubers. They do not conform to a specific geometric shape but are thick and swollen.

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