Mnemonics: The Invisible Living World: Beyond Our Naked Eye | Science Curiosity Class 8 - New NCERT PDF Download

 1. Basic Parts of a Cell 

Mnemonic: "Many Cats Nap Calmly"

• Many: Mitochondria — powerhouse of the cell, produces energy.
• Cats: Cytoplasm — jelly-like substance where cell processes occur.
• Nap: Nucleus — controls cell activities and contains genetic material.
• Calmly: Cell membrane — regulates what enters and exits the cell.

Basic Parts of Cell

 2. Levels of Organisation in Living Organisms 

Mnemonic: "Cute Tiny Owls Order Oranges"

• Cute: Cell — basic unit of life.
• Tiny: Tissue — group of similar cells working together.
• Owls: Organ — different tissues form an organ (e.g., heart).
• Order: Organ system — organs working together (e.g., circulatory system).
• Oranges: Organism — complete living entity made of organ systems.

3. Categories of Microorganisms 

Mnemonic: "Pink Frogs Bite All"

• Pink: Protozoa — single-celled organisms (e.g., Amoeba, Paramecium).
• Frogs: Fungi — yeast (unicellular) or mould (multicellular), no chlorophyll.
• Bite: Bacteria — unicellular with nucleoid, can be beneficial or harmful.
• All: Algae — often green, photosynthetic microorganisms.

 4. Shapes of Bacteria 

Mnemonic: "Silly Cats Sing Randomly"

• Silly: Spherical — round-shaped bacteria (e.g., cocci).
• Cats: Comma — comma-shaped bacteria (e.g., vibrio).
• Sing: Spiral — spiral-shaped bacteria (e.g., spirilla).
• Randomly: Rod-shaped — rod-like bacteria (e.g., bacilli).

 5. Favourable Conditions for Microorganism Growth 

Mnemonic: "Tom And Milk"

• Tom: Temperature — optimal or warm conditions promote growth.
• And: Air — some microbes need oxygen, others thrive without it.
• Milk: Moisture — wet conditions enhance microbial growth.

 6. Uses of Microorganisms in Food 

Mnemonic: "Big Chefs Invent Cuisines"

• Big: Baking bread — yeast ferments to produce CO₂, making dough rise.
• Chefs: Making cakes/pastries — yeast or bacteria aid in fermentation.
• Invent: Fermentation of idli/dosa batter — microbes ferment batter for texture.
• Cuisines: Curd formation — bacteria like Lactobacillus convert milk to curd.

7. Differences Between Plant and Animal Cells

​Mnemonic: “​Pretty Vivid Clever Plants”

• Pretty (P): Plant Cell Wall — present in plant, absent in animal.
• Vivid (V): Vacuole — large in plant, small/absent in animal.
• Clever (C): Chloroplast — present in plant, absent in animal.
• Plants (P): Plant shape fixed (due to cell wall), animal shape variable.

8. Beneficial Roles of Microorganisms

​Mnemonic: “Fine Foods Keep Nature Green”

• Fine: Fermentation (bread, cakes, idli, dosa, curd)
• Foods: Food supplements (Spirulina, Chlorella)
• Keep: Keeping environment clean (decomposition, manure)
• Nature: Nitrogen fixation (Rhizobium in legumes)
• Green: Gas production (biogas from waste)