🌿 Chapter 5 – Life Processes

🌿 Chapter 5 – Life Processes

✳️ What are Life Processes?

Basic functions performed by living organisms to maintain life.
Examples: Nutrition, Respiration, Transportation, Excretion

🗣️ Kannada: ಜೀವಿಗಳು ಜೀವ ಉಳಿಸಲು ಮಾಡುವ ಪ್ರಕ್ರಿಯೆಗಳನ್ನು ಜೀವನ ಪ್ರಕ್ರಿಯೆಗಳು ಎನ್ನುತ್ತಾರೆ.






🍞 1. Nutrition

It is the process of taking food and using it for energy, growth, and repair.

🔸 Types of Nutrition

Type

 Description

 Examples
Autotrophic

 Organisms prepare their own
food using sunlight, CO₂,
 and water (Photosynthesis)


 Green plants, algae
Heterotrophic

 Organisms depend on
others for food

 Humans, animals, fungi

🌞 Photosynthesis (Autotrophic Nutrition)

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

Raw materials: CO₂, Water, Sunlight, Chlorophyll
Site: Chloroplasts (contain green pigment chlorophyll)

🗣️ Kannada: ಹಸಿರು ಸಸ್ಯಗಳು ಸೂರ್ಯನ ಬೆಳಕು, ನೀರು ಮತ್ತು ಕಾರ್ಬನ್ ಡೈಆಕ್ಸೈಡ್ ಬಳಸಿ ಆಹಾರ ತಯಾರಿಸುವ ಪ್ರಕ್ರಿಯೆ.

🌿 Stomata

Tiny pores on leaves for gas exchange and water loss (transpiration).
Controlled by guard cells.

🍄 Heterotrophic Nutrition – Types

Type Description Example
Saprophytic
    		     Feeds on dead matter

 Mushroom, bread mould
Parasitic

     Takes food from
        living host

 Cuscuta, leech, tapeworm
Holozoic

     Takes food inside
     and digests it

 Amoeba, Humans

🧫 Nutrition in Amoeba

  • Takes food using finger-like projections — pseudopodia

  • Forms food vacuole → digestion → absorption → egestion

👨‍⚕️ Nutrition in Humans

Steps:
1️⃣ Ingestion → 2️⃣ Digestion → 3️⃣ Absorption → 4️⃣ Assimilation → 5️⃣ Egestion

Organs involved:
Mouth → Oesophagus → Stomach → Small intestine → Large intestine → Anus

Glands: Salivary glands, Liver, Pancreas, Intestinal glands

🦷 Mouth

  • Teeth grind food

  • Saliva (enzyme amylase) converts starch → sugar

🥣 Stomach

  • Gastric juice = Pepsin + HCl + Mucus

  • Pepsin → proteins → peptones

  • HCl → acidic medium

  • Mucus → protects wall

🧬 Small Intestine

  • Bile (from liver) → breaks fats

  • Pancreatic juice (from pancreas) → breaks proteins, fats, starch

  • Intestinal juice → completes digestion

  • Villi absorb nutrients into blood

🚽 Large Intestine

  • Absorbs water

  • Removes waste through anus

💨 2. Respiration

Process of breaking down food to release energy (ATP).

🔹 Types of Respiration


Type

 Oxygen

Site

End Product

Energy                           

Aerobic

Present

    Mitochondria

CO₂ + H₂O

    High

Anaerobic

 Absent

    Cytoplasm        

Alcohol    
/ Lactic acid

    Low

🗣️ Kannada: ಆಹಾರವು ಕೋಶಗಳಲ್ಲಿ ಆಮ್ಲಜನಕದ ಸಹಾಯದಿಂದ ಶಕ್ತಿಗೆ ಪರಿವರ್ತನೆಯಾಗುವ ಪ್ರಕ್ರಿಯೆ.

🫁 Respiration in Humans

Main organs: Nose → Pharynx → Larynx → Trachea → Bronchi → Lungs

Exchange of gases in alveoli (tiny air sacs in lungs)

Pigment: Haemoglobin carries oxygen

Mechanism:

  • Inhalation: Diaphragm contracts → chest expands

  • Exhalation: Diaphragm relaxes → chest contracts

🌳 Respiration in Plants

  • Gaseous exchange through stomata, lenticels, roots.

  • Simpler process as there are no special organs.

❤️ 3. Transportation

🩸 In Humans

Circulatory System: Heart + Blood + Blood Vessels (Arteries, Veins, Capillaries)

Component Function
Heart Pumps blood
Arteries Carry oxygenated blood away from heart
Veins Carry deoxygenated blood to heart
Capillaries Exchange of materials between blood & cells

🗣️ Kannada: ಹೃದಯ, ರಕ್ತ, ರಕ್ತನಾಳಗಳು ಸೇರಿ ಸಂಚಲನ ವ್ಯವಸ್ಥೆ ರಚಿಸುತ್ತವೆ.

❤️ Double Circulation

Blood passes through heart twice in one complete cycle — ensures oxygen-rich blood supply.

💧 Lymph

Colorless fluid that transports fats and removes extra fluid from tissues.
Contains lymphocytes that fight infections.

🌿 Transportation in Plants

Tissue

 Function
Xylem

     Carries water & minerals from roots to leaves
Phloem

     Carries food from leaves to other parts (Translocation)

Transpiration: Loss of water vapor from aerial parts.
Osmosis: Movement of water from low to high concentration through membrane.

🚽 4. Excretion

Removal of waste products from the body.

👤 In Humans

Organs: Kidneys, Ureters, Urinary bladder, Urethra

Functional unit: Nephron

Parts of Nephron:

  • Bowman’s capsule

  • Glomerulus

  • Tubule

Steps in Urine Formation:

  1. Filtration of blood

  2. Reabsorption of useful substances

  3. Excretion of waste (urea, uric acid)

🗣️ Kannada: ದೇಹದಿಂದ ಅಶುದ್ಧ ವಸ್ತುಗಳನ್ನು ಹೊರಹಾಕುವ ಪ್ರಕ್ರಿಯೆ – ವಿಸರ್ಜನೆ.

🌱 Excretion in Plants

  • Gaseous wastes → through stomata

  • Water → by transpiration

  • Gums/resins → stored in old xylem

  • Waste → through roots, falling leaves

📘 Summary Table

Life Process

 Function

 Main Organs
Nutrition

     Intake & use of food

     Mouth, Stomach, Intestine
Respiration

     Energy release

     Lungs
Transportation

     Circulation of    
    food & gases

     Heart, Blood
Excretion     Waste removal     Kidneys

🧠 Exam Tips

✅ Learn equations – Photosynthesis, Respiration
✅ Label diagrams – Digestive system, Respiratory system, Heart, Nephron
✅ 2 marks → Differences (Aerobic/Anaerobic, Arteries/Veins, Xylem/Phloem)
✅ 3 marks → Explain processes
✅ 4 marks → Diagram-based questions


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