Chapter 6: Anatomy of Flowering Plants | Class 11 Biology Notes PDF Download | NEET 2027

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As a NEET Dropper, I'm sharing my complete short notes of Chapter 6: Anatomy of Flowering Plants with you all.

Dicot vs Monocot Root, Stem, Leaf + Secondary Growth + Annual Rings - sab cover hai! 🔬

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_Class 11 Biology | NCERT Line-by-Line + PYQ Hotspots | 3-4Q Fix Aate Hain_  

### *1. The Tissues* `1Q Pakka`  

*A. Meristematic Tissue* = Dividing cells

**Type** **Location** **Function** **NEET Point**

**Apical** Root tip, Shoot tip Primary growth = Length increase Causes elongation

**Intercalary** Base of leaves, Internodes Elongation of internodes Monocots = Grass

**Lateral** Cambium, Cork cambium Secondary growth = Girth increase Dicots only, Absent in monocots

*B. Permanent Tissue* = Mature cells  

1. *Simple Permanent*: All cells similar  

   - *Parenchyma*: Living, Thin wall, Cellulose, Isodiametric. *Functions*: Storage, Photosynthesis = Chlorenchyma, Buoyancy = Aerenchyma in hydrophytes.  

   - *Collenchyma*: Living, Cellulose + Pectin thickening at corners. *Function*: Mechanical support in young stem, petiole. Absent in roots.  

   - *Sclerenchyma*: Dead, Lignified thick wall. *Types*: Fibres = Long, Sclereids = Gritty = Guava, Pear, Sapota. *Function*: Mechanical support.  

2. *Complex Permanent*: More than 1 type of cell = Xylem + Phloem = Conducting tissue  

   - *Xylem*: Water conduction. *Components*: Tracheids, Vessels, Xylem parenchyma = Only living, Xylem fibres.  

     *NEET Gold*: Vessels absent in Gymnosperms. Present in Angiosperms. Tracheids = Main water transport in Gymnosperms.  

   - *Phloem*: Food conduction. *Components*: Sieve tube elements, Companion cells, Phloem parenchyma, Phloem fibres = Bast fibres = Only dead.  

     *NEET Gold*: Companion cells maintain pressure gradient. Sieve tubes = Enucleate. Phloem parenchyma absent in most monocots.  

### *2. Tissue System*  

1. *Epidermal Tissue System*: Epidermis, Stomata, Trichomes, Root hairs.  

   - *Stomata*: Guard cells = Kidney shaped in dicot, Dumb-bell shaped in monocot. Subsidiary cells present.  

   - *Trichomes*: Multicellular, prevent water loss.  

2. *Ground Tissue System*: All tissues except epidermis + vascular. Cortex, Pericycle, Pith, Medullary rays.  

3. *Vascular Tissue System*: Xylem + Phloem.  

   - *Radial*: Xylem & Phloem alternate radii = Roots.  

   - *Conjoint*: Xylem & Phloem together = Stem. Collateral = Phloem outside. Bicollateral = Phloem on both sides = _Cucurbita_.  

   - *Open*: Cambium present b/w xylem & phloem = Dicot stem. *Closed*: Cambium absent = Monocot stem.  

### *3. Anatomy of Dicot & Monocot Plants* `2Q Aate Hain`  

*A. Dicot Root vs Monocot Root*

**Feature** **Dicot Root** **Monocot Root**

**Xylem Bundles** 2-4 = Diarch to Tetrarch 8+ = Polyarch

**Pith** Small or Absent Large, Well developed

**Secondary Growth** Present Absent

**Pericycle** Gives lateral roots + Vascular cambium + Cork cambium Gives lateral roots only

**Example** Gram, Sunflower Maize, Wheat

*B. Dicot Stem vs Monocot Stem*

**Feature** **Dicot Stem** **Monocot Stem**

**Epidermis** With trichomes Without trichomes, Silica present

**Hypodermis** Collenchymatous Sclerenchymatous

**Ground Tissue** Differentiated = Cortex, Endodermis, Pericycle, Pith Undifferentiated = Parenchyma

**Vascular Bundles** Arranged in ring, Conjoint, Open, Endarch Scattered, Conjoint, Closed, Endarch

**Bundle Sheath** Absent Sclerenchymatous

**Pith** Present = Medulla Absent

**Secondary Growth** Present Absent

**Example** Sunflower, Mango Maize, Bamboo

*C. Dicot Leaf = Dorsiventral vs Monocot Leaf = Isobilateral*

**Feature** **Dicot Leaf** **Monocot Leaf**

**Stomata** More on lower epidermis Equal on both surfaces

**Mesophyll** Differentiated = Palisade + Spongy Undifferentiated

**Bundle Sheath** Single layered Double layered = Outer parenchyma, Inner thick wall

**Bulliform Cells** Absent Present in upper epidermis = Rolling of leaf in grasses during drought

**Venation** Reticulate Parallel

**Example** Mango, Peepal Maize, Grass

### *4. Secondary Growth* `1Q Pakka Dicots Only`  

*A. Secondary Growth in Dicot Stem*  

1. *Vascular Cambium*: Intrafascicular cambium + Interfascicular cambium → Cambial ring.  

   - *Activity*: Cuts secondary xylem inside, secondary phloem outside. More xylem formed.  

   - *Spring Wood*: Light colour, Low density, Wider vessels. Formed in spring.  

   - *Autumn Wood*: Dark colour, High density, Narrow vessels. Formed in autumn/winter.  

   - *Annual Ring* = Spring wood + Autumn wood = 1 year. Used to determine age = Dendrochronology.  

   - *Heartwood*: Dead, Dark, Central part. Tannins, Resins, Oils deposited. Hard, Durable.  

   - *Sapwood*: Living, Light, Peripheral part. Water conduction.  

2. *Cork Cambium = Phellogen*: Arises from cortex.  

   - *Activity*: Cuts cork = Phellem outside = Dead, Suberised. Cuts secondary cortex = Phelloderm inside = Living.  

   - *Periderm* = Phellem + Phellogen + Phelloderm.  

   - *Lenticels*: Lens shaped openings in bark for gaseous exchange. Formed during secondary growth.  

*B. Secondary Growth in Dicot Root*  

- *Vascular Cambium*: Derived from tissue below phloem + Pericycle.  

- *Cork Cambium*: Derived from Pericycle.  

- *NEET Point*: Secondary growth absent in monocots because cambium absent.  

### *5. Last 5 Year PYQ One Liners* `Ratta Maar Le`  

1. *Bulliform cells* = Monocot leaf = Rolling of leaf = NEET 2024, 2021.  

2. *Companion cells* = Phloem = Maintain pressure gradient = NEET 2023.  

3. *Heartwood* = Dead, Central, Durable = NEET 2022, 2019.  

4. *Annual rings* = Secondary xylem = Spring + Autumn wood = NEET 2021.  

5. *Lenticels* = Periderm = Gaseous exchange = NEET 2020.  

6. *Polyarch xylem* = Monocot root = NEET 2023.  

7. *Endarch xylem* = Protoxylem towards centre = Stem = NEET 2019.  

8. *Exarch xylem* = Protoxylem towards periphery = Root = NEET 2018.  

9. *Collenchyma absent* = Roots, Monocot stem = NEET 2017.  

10. *Sieve tubes* = Enucleate but living = Phloem = NEET 2022.  

11. *Casparian strips* = Endodermis = Suberin = Root = NEET 2020.  

12. *Vessels absent* = Gymnosperms = NEET 2016.  

13. *Aerenchyma* = Hydrophytes = Buoyancy = NEET 2019.  

14. *Pericycle* = Gives lateral roots in all + Cambium in dicot root = NEET 2018.  

*Diagrams for NEET*: T.S of Dicot root, Monocot root, Dicot stem, Monocot stem, Dorsiventral leaf, Isobilateral leaf, Lenticel, Annual ring.