Anatomy of flowering plant-1(6.1The Tissue system)#Neet#Biology#10+l#Botany
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Notes of anatomy of Monocot Leaf
### General Characteristics
- Found in grasses, maize, and rice
- Both leaf surfaces are equally green and can face the sun
- Shows no distinction into petiole and lamina
- Features parallel venation
- Has sheathing leaf base
- Examples include Dracaena, spider plant, grasses, and lawn grass
### Epidermis
- Single-layered, made of parenchyma cells
- Protected by cuticle
- Contains bulliform (motor) cells in upper epidermis
- Interrupted by stomata
#### Bulliform Cells
- Large, thin-walled, protruding cells
- Highly vacuolated and can store water
- Functions:
- Help in rolling of leaves during water deficiency
- Aid in unrolling when water becomes available
### Stomatal Apparatus
- Stomata lined by dumbbell-shaped guard cells
- Guard cell characteristics:
- Thick towards inner side, thin towards outer side
- Contains nucleus, chloroplast, and tiny vacuoles
- Surrounded by subsidiary cells
- Functions:
- Gaseous exchange (CO2 and O2)
- Helps in transpiration
- Protection of internal tissues
### Mesophyll
- Located between upper and lower epidermis
- Composed of large isodiametric cells (oval or rounded)
- Contains chlorenchymatous cells with chloroplasts
- Functions:
- Photosynthesis
- Gaseous exchange
### Vascular Bundle
- Contains xylem and phloem
- Characteristics:
- Conjoint, collateral, and closed
- Bounded by bundle sheath
- Bundle sheath cells contain chloroplasts
- Large bundles have bundle sheath extensions made of sclerenchyma
- Protoxylem lacuna present towards upper side
### Midrib
- Thickest part of leaf
- Features:
- Shows shallow groove on upper surface
- Contains sclerenchymatous patches on both sides of vascular bundle
- Does not contain mesophyll
- Provides mechanical strength
### Adaptations for Water Management
- Bulliform cells help in leaf rolling during dry conditions
- Stomata regulate water loss through transpiration
- Bundle sheath extensions provide mechanical support
- Specialized structures aid in water conservation and structural integrity