What are primary, secondary and tertiary roots ?

Explanation

### Step-by-Step Solution:

1. **Definition of Primary Roots**:
- Primary roots are the first roots that develop from the seed during germination. They grow vertically downwards into the soil, anchoring the plant and absorbing water and nutrients.

2. **Formation of Secondary Roots**:
- From the primary roots, smaller lateral roots emerge. These smaller roots are referred to as secondary roots. They branch out from the primary root and help in further anchoring the plant and enhancing its ability to absorb nutrients.

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