Mnemonics: Plant Growth & Development | Biology Class 11 - NEET PDF Download

1. Phases of Growth 

Mnemonic: "MEM": (Meristematic, Elongation, Maturation) 

2. Sequence of the Developmental Process in a Plant Cell

Mnemonic: "Many Plants Expand Daily, Making Strong Cells"

• Many → Meristematic cells
• Plants → Plasmatic growth
• Expand → Expansion (Elongation)
• Daily → Differentiation
• Making → Maturation
• Strong → Senescence
• Cells → Cell Death

3. Types of Growth Regulators 

(Auxins, Gibberellins, Cytokinins, Ethylene, Abscisic Acid):Mnemonic: "AGE CA"

Mnemonic Explanation: 

• A = Auxins: Promote growth and fruit development.
• G = Gibberellins: Stimulate stem elongation and seed germination.
• E = Ethylene: Influences fruit ripening and flower opening.
• C = Cytokinins: Promote cell division and delay ageing.
• A = Abscisic Acid: Induces seed dormancy and stress responses.

4. Functions of Growth Regulators

(a) Auxin   

Mnemonic: "Rooty Flowers Avoid Lazy Cutting For Weedless Clean Xylem"

• Rooty → Root initiation (in stem cuttings)
• Flowers → Flowering promotion (e.g., in pineapples)
• Avoid → Abscission prevention (prevents early leaf/fruit drop)
• Lazy → Lateral bud inhibition (Apical dominance)
• Cutting → Cut shoot grows side branches (after decapitation)
• For → Fruit without seeds (Parthenocarpy in tomatoes)
• Weedless → Weed killer (2,4-D kills dicot weeds, not monocots)
• Clean → Cell division
• Xylem → Xylem differentiation

Apical dominance in plants : (a) A plant with apical bud intact (b) A plant with apical bud removed Note the growth of lateral buds into branches after decapitation.

Mnemonic: "GROW FAST SEEDS"

• G – Grape stalk elongation
  (Gibberellins increase length of the grape stalk)

• R – Rosette bolting
  (Bolting in beet, cabbage — sudden elongation before flowering)

• O – Overcome dwarfism
  (Helps increase plant height in dwarf varieties)

• W – Wider apple shape
  (Improves apple size and shape)

• F – Fruit stay longer
  (Delays senescence — fruits remain on tree longer)

• A – Alcohol making
  (Used in malting for brewing industry)

• S – Sugarcane yield
  (Increases stem length — more sugar per acre)

• T – Tallness
  (General stem elongation in various plants)

• S – Seed formation early
  (Induces early maturity in juvenile conifers)

(c) Cytokinin

Mnemonic: "New Cute Leaves Grow Longer, Stay Young"

• New → New cell formation (promotes cell division, especially cytokinesis)

• Cute → Chloroplast development in leaves

• Leaves → Leaf production (new leaf formation)

• Grow → Growth of lateral shoots (overcomes apical dominance)

• Longer → Lateral shoot formation (adventitious shoots)

• Stay → Senescence delayed

• Young → Youth maintained by nutrient mobilisation

Tip: Cytokinins = "Cell division & Staying young"

(d) Ethylene 

Mnemonic: "Ripe Fruits Fall, Sleep Breaks, Roots Rise"

• Ripe → Ripening of fruits (like bananas, apples, tomatoes)

• Fruits → Fruit set & flowering (in pineapples, mango)

• Fall → Abscission (leaves, flowers, and fruit drop)

• Sleep → Seed/bud dormancy broken

• Breaks → Bud sprouting & seed germination (e.g., in peanuts, potatoes)

• Roots → Root growth and root hair formation

• Rise → Shoot elongation in water (like in deep-water rice)

• Bonus: Ethephon = Ethylene releaser (used in agriculture)

Tip: Ethylene = "Ripening & dropping hormone"

(e) Abscisic Acid (ABA) 

 Mnemonic: "Always Be Asleep During Stress"

1. Always → Abscission regulation (leaf/fruit fall)

2. Be → Bud dormancy

3. Asleep → Seed dormancy (inhibits germination)

4. During → Development of seeds (helps maturation)

5. Stress → Stress tolerance (closes stomata, fights desiccation)

Tip: ABA = "Sleepy & stress hormone" (antagonist to gibberellins)