Class 7 Science Chapter 9 Life Processes in Animals Notes | Curiosity 2026-27 | Amresh Academy

 

 

🌟 Class 7 Science Curiosity – Chapter 9 Notes

🫀 Life Processes in Animals | Amresh Academy

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📘 Introduction

All living organisms perform certain life processes to survive 🌱

👉 These include:

• 🍽️ Nutrition
• 🌬️ Respiration
• 💧 Excretion
• 🔄 Reproduction

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⚙️ 1. Life Processes

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👉 Essential for survival of animals

📌 Focus of this chapter:

• Nutrition (Digestion)
• Respiration

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🍽️ 2. Nutrition in Animals

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👉 Food provides energy ⚡

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🧠 Key Concept:

• Complex food → broken into simpler substances
• Occurs in alimentary canal (mouth → anus)

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🫃 3. Human Digestive System

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👄 Mouth

• Teeth chew food
• Saliva breaks starch → sugar

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🔄 Oesophagus

• Pushes food using wave-like movement (peristalsis)

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🥣 Stomach

• Churns food
• Digestive juices break proteins
• Acid kills bacteria
• Mucus protects lining

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🧪 Small Intestine

• Longest part (~6 m)
• Liver → bile
• Pancreas → digestive juice
• Villi absorb nutrients into blood

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💧 Large Intestine

• Absorbs water & salts
• Forms stool

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🚽 Anus

• Waste expelled (egestion)

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🥗 Healthy Tips:

• Eat fiber-rich food 🍎
• Brush teeth twice daily 🪥

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🐄 4. Digestion in Other Animals

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🐄 Ruminants (cow):

• Chew food twice (rumination)

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🐦 Birds:

• Use gizzard to grind food

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🌬️ 5. Respiration in Animals

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👉 Respiration = chemical process

👉 Glucose + Oxygen → Energy

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👉 Breathing = physical process

👉 Inhaling & exhaling air

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🫁 6. Human Respiratory System

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🔹 Parts:

• 👃 Nostrils
• 🌫️ Nasal passages
• 🫁 Lungs (alveoli)
• 🦴 Rib cage
• ⬇️ Diaphragm

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🔄 Breathing Mechanism:

🌬️ Inhalation:

• Ribs move up/out
• Diaphragm moves down
  👉 Air enters lungs

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🌬️ Exhalation:

• Ribs move down/in
• Diaphragm moves up
  👉 Air goes out

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🔬 Gas Exchange:

• Oxygen → enters blood
• Carbon dioxide → removed

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⚗️ Equation:

👉 Glucose + Oxygen → Carbon dioxide + Water + Energy

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📊 Air Comparison:

Type	Oxygen	CO₂
Inhaled	~21%	~0.04%
Exhaled	~16–17%	~4–5%

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🐟 7. Respiration in Other Animals

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• 🐦 Birds → Lungs
• 🐟 Fish → Gills
• 🐸 Amphibians → Skin + lungs
• 🐛 Earthworms → Moist skin

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❤️ 8. Circulatory System

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👉 Includes:

• ❤️ Heart
• 🩸 Blood
• 🧵 Blood vessels

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👉 Functions:

• Transport oxygen & nutrients
• Remove waste

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📌 9. Key Notes

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✔️ Digestion differs in animals 🐾

✔️ Breathing ≠ Respiration

✔️ Healthy habits are important

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💡 Good Practices:

• 🪥 Oral hygiene
• 🥗 Balanced diet
• 🧘 Breathing exercises

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⚠️ Warning:

🚫 Smoking damages lungs

🚫 Causes serious diseases

🚫 Harmful to others (passive smoking)

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📌 Final Summary

👉 Life processes keep organisms alive 🌍

👉 Key systems:

• Digestive system 🍽️
• Respiratory system 🌬️
• Circulatory system ❤️

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✨ Perfect for revision + exams + concept clarity 🚀

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