Long Answer
Medium difficulty • Structured explanation
Question 1
Long FormCompare the structure and functions of the three types of root systems found in flowering plants, highlighting their adaptive significance.
- Tap root system (dicots, e.g., mustard): primary root develops from radicle and bears secondary and tertiary laterals; penetrates deep into soil enabling absorption of water and minerals from lower layers and firm anchorage.
- Fibrous root system (monocots, e.g., wheat): primary root short-lived and replaced by numerous roots from stem base; spread widely in upper soil layers for efficient surface absorption and binding of topsoil, preventing erosion.
- Adventitious roots arise from non-radicle parts (stem, leaves) in plants like grass, Monstera, and banyan; serve specialised functions such as clinging support, prop roots for mechanical support, and aerial roots for gas exchange.
- Functions common to all root systems: absorption of water and dissolved minerals via root hairs; anchorage of plant against physical forces; storage of food reserves in swollen roots (e.g., carrot, sweet potato).
- Synthesis of plant growth regulators (cytokinins) is another important function of roots, influencing cell division and shoot development.
- The type of root system is thus a fundamental adaptation to habitat and lifestyle, with each type offering specific mechanical and physiological advantages to the plant.
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