Class 11 Biology - Chapter 5
Morphology of Flowering Plants (Student Notes)
Root
• Types: Tap root (dicots), Fibrous root (monocots), Adventitious root (other than radicle).
• Regions: root cap, meristematic zone, elongation zone, maturation zone (with root hairs).
• Modifications: storage (carrot, radish), support (prop roots in banyan, stilt roots in maize),
respiration (pneumatophores in mangroves).
Stem
• Functions: conduction, storage, photosynthesis.
• Modifications: Underground (potato - tuber, ginger - rhizome, onion - bulb).
• Aerial (tendrils in cucumber, thorns in Bougainvillea). Sub-aerial (stolon, runner, offset).
Leaf
• Parts: leaf base, petiole, lamina.
• Venation: reticulate (dicots), parallel (monocots).
• Types: simple, compound (pinnate - neem, palmate - silk cotton).
• Phyllotaxy: alternate (china rose), opposite (guava), whorled (Alstonia).
• Modifications: tendrils (pea), spines (cactus), storage (onion, garlic).
Inflorescence
• Racemose: main axis continuous (mustard).
• Cymose: main axis ends in flower (jasmine).
• Special: head (sunflower).
Flower
• Reproductive unit, modified shoot.
• Parts: calyx, corolla, androecium, gynoecium.
• Symmetry: actinomorphic (mustard), zygomorphic (pea), asymmetric (canna).
• Placentation: marginal (pea), axile (china rose), parietal (mustard), basal (sunflower), free
central (dianthus).
Fruit
• Mature ovary after fertilisation.
• True fruit (mango, tomato), False fruit (apple, strawberry).
• Dry & fleshy fruits.
Seed
• Formed after double fertilisation.
• Dicot seeds: 2 cotyledons (pea, bean).
• Monocot seeds: 1 cotyledon (maize, rice).
Morphology of Flowering Plants (Student Notes)
Root
• Types: Tap root (dicots), Fibrous root (monocots), Adventitious root (other than radicle).
• Regions: root cap, meristematic zone, elongation zone, maturation zone (with root hairs).
• Modifications: storage (carrot, radish), support (prop roots in banyan, stilt roots in maize),
respiration (pneumatophores in mangroves).
Stem
• Functions: conduction, storage, photosynthesis.
• Modifications: Underground (potato - tuber, ginger - rhizome, onion - bulb).
• Aerial (tendrils in cucumber, thorns in Bougainvillea). Sub-aerial (stolon, runner, offset).
Leaf
• Parts: leaf base, petiole, lamina.
• Venation: reticulate (dicots), parallel (monocots).
• Types: simple, compound (pinnate - neem, palmate - silk cotton).
• Phyllotaxy: alternate (china rose), opposite (guava), whorled (Alstonia).
• Modifications: tendrils (pea), spines (cactus), storage (onion, garlic).
Inflorescence
• Racemose: main axis continuous (mustard).
• Cymose: main axis ends in flower (jasmine).
• Special: head (sunflower).
Flower
• Reproductive unit, modified shoot.
• Parts: calyx, corolla, androecium, gynoecium.
• Symmetry: actinomorphic (mustard), zygomorphic (pea), asymmetric (canna).
• Placentation: marginal (pea), axile (china rose), parietal (mustard), basal (sunflower), free
central (dianthus).
Fruit
• Mature ovary after fertilisation.
• True fruit (mango, tomato), False fruit (apple, strawberry).
• Dry & fleshy fruits.
Seed
• Formed after double fertilisation.
• Dicot seeds: 2 cotyledons (pea, bean).
• Monocot seeds: 1 cotyledon (maize, rice).
