Describe various root modifications associated with food storage, mechanical support and respiration.

Solution:

1. Modification for Food Storage:

Tap Roots:

• Conical (carrot): Broad at top, tapering at bottom
• Fusiform (radish): Swollen in middle, tapering at both ends
• Napiform (turnip): Spherical top, abruptly tapering

Adventitious Roots:

• Tuberous roots (sweet potato): Swollen, no definite shape
• Fasciculated tuberous roots (Dahlia): Cluster of swollen roots

1. Modification for Mechanical Support:

• Prop roots (banyan): Arise from branches, grow downward, provide pillar-like support
• Stilt roots (maize, sugarcane): Arise from lower nodes, grow obliquely into soil
• Climbing roots (betel, Pothos): Arise from nodes, help climb supports

III. Modification for Respiration:

• Pneumatophores (Rhizophora): Negatively geotropic roots with lenticels in waterlogged soils