🧬 Chapter 1 – Life Processes (Biology)

 📘 Subject: Biology

🧑‍🏫 Class: 10 CBSE
🧪 Book: Science (NCERT)

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🧠 What are Life Processes?

Life processes are activities performed by living beings to maintain life such as:

• Nutrition

• Respiration

• Transportation

• Excretion

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🍽️ 1. Nutrition

🔹 Definition: Process of taking in food and using it for energy, growth, repair.

🔸 Types of Nutrition:

Type	Example
Autotrophic	Plants
Heterotrophic	Animals, Humans

🌿 Autotrophic Nutrition (Photosynthesis)

• Occurs in green plants

• Uses sunlight, water, and CO₂

• Equation:
  6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ (in presence of sunlight & chlorophyll)

🍖 Heterotrophic Nutrition:

• Holozoic (Humans)

• Saprophytic (Fungi)

• Parasitic (Cuscuta, leech)

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💨 2. Respiration

🔹 Definition: Breakdown of food to release energy.

🔸 Types:

Type	With/Without O₂	End Product
Aerobic	With O₂	CO₂ + H₂O + Energy
Anaerobic	Without O₂	Alcohol + CO₂ + Less energy

🔸 Respiration in Humans:

• Occurs in mitochondria

• Lungs are main respiratory organs

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🩸 3. Transportation

🔹 Definition: Movement of materials like oxygen, food, waste.

🚶 In Humans:

• Blood transports substances

• Heart pumps blood

• Arteries: carry blood away from heart

• Veins: carry blood toward the heart

• Capillaries: thin vessels for exchange

🌿 In Plants:

• Xylem – transports water

• Phloem – transports food

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🚽 4. Excretion

🔹 Definition: Removal of metabolic waste from the body

In Humans:

• Kidneys remove urea

• Urinary system: Kidneys → Ureter → Bladder → Urethra

In Plants:

• Waste is stored in leaves, gums, resins

• Waste removed by falling leaves or bark

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📌 Important Keywords

Term	Meaning
Peristalsis	Wave-like muscle movement in food pipe
Nephron	Functional unit of kidney
Stomata	Tiny pores in leaves for gas exchange
Alveoli	Air sacs in lungs

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💡 Diagram Suggestions (for your blog or notes)

✅ Labelled diagrams:

• Human Digestive System

• Human Respiratory System

• Human Heart

• Nephron (Kidney unit)

• Open & Closed Stomata

• Photosynthesis process

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📝 Extra Questions & Answers

Q1: What is the role of saliva in digestion?
👉 Saliva contains enzyme amylase, which breaks down starch into sugar.

Q2: What is the difference between artery and vein?
👉 Artery: Thick-walled, carries oxygenated blood
👉 Vein: Thin-walled, carries deoxygenated blood

Q3: What is nephron?
👉 It is the functional unit of kidney that filters blood and forms urine.

Q4: Why is transportation necessary?
👉 To carry nutrients, gases, and waste products to/from cells.

Q5: Define photosynthesis and give the equation.
👉 Photosynthesis is the process by which green plants make food using sunlight.
Equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

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✨ Summary Points

• Nutrition: autotrophic (plants) & heterotrophic (humans)

• Respiration: releases energy (aerobic/anaerobic)

• Transportation: blood in humans, xylem/phloem in plants

• Excretion: kidneys in humans, leaf fall in plants