🔹 What are Life Processes?

Life processes are the basic functions performed by living organisms to maintain life.

Main Life Processes:

1. Nutrition
2. Respiration
3. Transportation
4. Excretion

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🍎 1. Nutrition

🔹 Definition:

The process by which organisms obtain and use food.

🔹 Types of Nutrition:

1. Autotrophic Nutrition

• Organisms make their own food.
• Example: Plants

🌿 Photosynthesis:

• Process by which plants make food using sunlight.

Equation:$$6CO_2 + 6H_2O \xrightarrow{sunlight + chlorophyll} C_6H_{12}O_6 + 6O_2$$6CO2​+6H2​Osunlight+chlorophyll​C6​H12​O6​+6O2​

2. Heterotrophic Nutrition

• Organisms depend on others for food.

Types:

• Holozoic (Humans, animals)
• Saprophytic (Fungi)
• Parasitic (Leech)

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🍽️ Human Digestive System

Steps:

1. Ingestion
2. Digestion
3. Absorption
4. Assimilation
5. Egestion

Important Organs:

• Mouth (saliva, amylase)
• Stomach (HCl, pepsin)
• Small intestine (digestion + absorption)
• Liver (bile)
• Pancreas (enzymes)

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🌬️ 2. Respiration

🔹 Definition:

Process of breaking down food to release energy.

🔹 Types:

1. Aerobic Respiration

• Uses oxygen
• Produces more energy

$$Glucose + O_2 → CO_2 + H_2O + Energy$$Glucose+O2​→CO2​+H2​O+Energy

2. Anaerobic Respiration

• Without oxygen
• Less energy

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🔹 Human Respiratory System:

• Nose → Trachea → Bronchi → Lungs → Alveoli

🔸 Alveoli:

• Site of gas exchange
• Large surface area

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🚚 3. Transportation

🔹 In Humans:

❤️ Blood:

• RBC → oxygen transport
• WBC → immunity
• Platelets → clotting

❤️ Heart:

• 4 chambers:
  • Right atrium
  • Right ventricle
  • Left atrium
  • Left ventricle

🔄 Double Circulation:

• Blood passes twice through heart

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🔹 In Plants:

Transport Tissues:

• Xylem → water
• Phloem → food

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🚽 4. Excretion

🔹 Definition:

Removal of waste products.

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🔹 Human Excretory System:

• Kidneys
• Ureters
• Urinary bladder
• Urethra

🔸 Nephron:

• Basic unit of kidney

Steps:

1. Filtration
2. Reabsorption
3. Urine formation

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🔹 In Plants:

• Waste removed by:
  • Leaves
  • Bark
  • Stomata

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⭐ Important Points (Exam Tips)

• Photosynthesis occurs in chloroplast
• Alveoli increase surface area
• Heart shows double circulation
• Nephron is functional unit of kidney
• Xylem & phloem are transport tissues

Diagrams (very useful for exams)

🧠 MCQs – Life Processes

🔹 1. Nutrition

Q1. Which process is used by plants to make food?
A) Respiration
B) Photosynthesis
C) Transpiration
D) Digestion
👉 Answer: B) Photosynthesis

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Q2. Which gas is taken in during photosynthesis?
A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen
👉 Answer: C) Carbon dioxide

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Q3. Chlorophyll is present in:
A) Mitochondria
B) Nucleus
C) Chloroplast
D) Ribosome
👉 Answer: C) Chloroplast

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Q4. Heterotrophic nutrition includes:
A) Autotrophs
B) Saprophytes
C) Producers
D) Plants
👉 Answer: B) Saprophytes

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🍽️ 2. Digestion

Q5. Where does digestion of protein begin?
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
👉 Answer: B) Stomach

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Q6. Which enzyme is present in saliva?
A) Pepsin
B) Trypsin
C) Amylase
D) Lipase
👉 Answer: C) Amylase

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Q7. The main site of absorption is:
A) Stomach
B) Small intestine
C) Large intestine
D) Mouth
👉 Answer: B) Small intestine

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🌬️ 3. Respiration

Q8. Aerobic respiration occurs in presence of:
A) Nitrogen
B) Oxygen
C) Carbon dioxide
D) Hydrogen
👉 Answer: B) Oxygen

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Q9. Which organ helps in breathing?
A) Heart
B) Kidney
C) Lungs
D) Liver
👉 Answer: C) Lungs

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Q10. Gas exchange occurs in:
A) Trachea
B) Bronchi
C) Alveoli
D) Nose
👉 Answer: C) Alveoli

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🚚 4. Transportation

Q11. Which part pumps blood?
A) Brain
B) Lungs
C) Heart
D) Kidney
👉 Answer: C) Heart

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Q12. RBC carries:
A) CO₂
B) Oxygen
C) Hormones
D) Enzymes
👉 Answer: B) Oxygen

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Q13. Which vessel carries blood away from heart?
A) Veins
B) Arteries
C) Capillaries
D) Lymph
👉 Answer: B) Arteries

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🌿 5. Transport in Plants

Q14. Xylem transports:
A) Food
B) Water
C) Oxygen
D) Hormones
👉 Answer: B) Water

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Q15. Phloem transports:
A) Water
B) Minerals
C) Food
D) Oxygen
👉 Answer: C) Food

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🚽 6. Excretion

Q16. Functional unit of kidney is:
A) Neuron
B) Nephron
C) Alveoli
D) Villus
👉 Answer: B) Nephron

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Q17. Urine is stored in:
A) Kidney
B) Ureter
C) Urinary bladder
D) Urethra
👉 Answer: C) Urinary bladder

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🔥 Mixed Concept Questions

Q18. Double circulation means:
A) Blood flows once
B) Blood flows twice through heart
C) Blood flows in one direction
D) No circulation
👉 Answer: B

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Q19. Which process releases energy?
A) Photosynthesis
B) Respiration
C) Digestion
D) Excretion
👉 Answer: B) Respiration

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Q20. Which organ removes nitrogenous waste?
A) Heart
B) Lungs
C) Kidney
D) Liver
👉 Answer: C) Kidney

🧪 CASE 1: Photosynthesis

A student kept two plants—one in sunlight and one in a dark room. After a few days, the plant in sunlight remained healthy, while the other showed poor growth.

Q1. Why did the plant in darkness show poor growth?

A) Lack of oxygen
B) Lack of water
C) No photosynthesis
D) Excess minerals
👉 Answer: C) No photosynthesis

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Q2. Which raw material was unavailable in the dark?

A) CO₂
B) Water
C) Sunlight
D) Chlorophyll
👉 Answer: C) Sunlight

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Q3. What is the role of chlorophyll?

A) Absorbs CO₂
B) Absorbs sunlight
C) Produces oxygen
D) Absorbs water
👉 Answer: B) Absorbs sunlight

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🍽️ CASE 2: Digestion

Rahul eats a heavy meal rich in proteins. His stomach secretes digestive juices to break down food.

Q4. Which enzyme helps in protein digestion in stomach?

A) Amylase
B) Lipase
C) Pepsin
D) Trypsin
👉 Answer: C) Pepsin

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Q5. What is the role of HCl in stomach?

A) Neutralizes acid
B) Kills bacteria & activates enzymes
C) Digests fats
D) Absorbs nutrients
👉 Answer: B)

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Q6. Where is most digestion completed?

A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
👉 Answer: C)

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🌬️ CASE 3: Respiration

During exercise, a person breathes faster and feels tired due to increased energy demand.

Q7. Why does breathing rate increase?

A) To remove nitrogen
B) To supply more oxygen
C) To reduce heart rate
D) To digest food
👉 Answer: B)

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Q8. Where does gas exchange occur?

A) Trachea
B) Bronchi
C) Alveoli
D) Nose
👉 Answer: C)

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Q9. Which gas is released during respiration?

A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen
👉 Answer: C)