A monocot root IS different from a dicot root by having

Analyze the question: It asks for a feature that separates a monocot root from a dicot root. Features found in both types of root cannot be the answer.

Concept:

| Feature | Monocot root | Dicot root | |---|---|---| | Endodermis | Present | Present | | Cambium | Absent (no secondary growth) | Present (formed between xylem and phloem) | | Pith | Large, well developed | Small or absent | | Xylem bundles | Many (polyarch) | Few (2 to 4 in number) | | Root hairs | Present in the piliferous layer | Present in the piliferous layer |

Step-by-step solution:

• A. Endodermis: Both root types have it, so it is not a difference.
• B. Cambium: A dicot root has cambium. A monocot root does not. The question asks what a monocot root has, so this option describes the dicot and is wrong.
• C. Wide pith: A monocot root has a large central pith. A dicot root has a very small pith or none, because the xylem usually fills the centre. This is a feature of the monocot root.
• D. Root hair: Both root types have them, so it is not a difference.

Answer: The monocot root differs from the dicot root by having a wide pith.

Exam tip: Remember "Monocot = Many bundles, Medullated (wide pith), no cambium." For "by having" questions, pick the feature the monocot has and the dicot lacks. Do not pick a feature that only the dicot has, such as cambium.