🌱 LIFE PROCESSES – Detailed Notes (Class 10 Biology)

Life processes are the basic activities performed by living organisms to maintain life. These processes help organisms obtain energy, grow, repair tissues, respond to stimuli, and reproduce. In humans and other organisms, life processes include Nutrition, Respiration, Transportation, and Excretion.

1️⃣ Nutrition

What is Nutrition?

Nutrition is the process by which organisms obtain food and utilize it for energy, growth, repair, and maintenance.

Types of Nutrition

1. Autotrophic Nutrition

Organisms prepare their own food.
Example: Green plants.
They use sunlight, carbon dioxide, and water.

This process is called Photosynthesis.

Photosynthesis Equation:

[
6CO_2 + 6H_2O \xrightarrow{Sunlight, Chlorophyll} C_6H_{12}O_6 + 6O_2
]

Raw materials needed:

Carbon dioxide (from air)
Water (from soil)
Sunlight
Chlorophyll (green pigment)

Stomata: Tiny pores in leaves that allow exchange of gases.

2. Heterotrophic Nutrition

Organisms depend on others for food.

Types:

Holozoic – Humans, Amoeba
Saprophytic – Fungi
Parasitic – Tapeworm

Nutrition in Amoeba

Amoeba follows holozoic nutrition.

Steps:

Ingestion
Digestion
Absorption
Assimilation
Egestion

It uses pseudopodia to engulf food (phagocytosis).

Nutrition in Humans

The human digestive system consists of:

Mouth
Oesophagus
Stomach
Small intestine
Large intestine
Anus

Steps of Human Digestion

Ingestion – Taking food into mouth.
Digestion – Breakdown of complex food.
Absorption – Nutrients absorbed in small intestine.
Assimilation – Used by body cells.
Egestion – Removal of undigested food.

2️⃣ Respiration

What is Respiration?

Respiration is the process of releasing energy from food.

It occurs inside cells in mitochondria.

Types of Respiration

1. Aerobic Respiration

Uses oxygen.
Produces more energy.
End products: CO₂ and H₂O.

Equation:
[
C_6H_{12}O_6 + 6O_2 → 6CO_2 + 6H_2O + Energy
]

2. Anaerobic Respiration

Occurs without oxygen.
Produces less energy.
In muscles → Lactic acid
In yeast → Alcohol + CO₂

Human Respiratory System

Main parts:

Nostrils
Nasal cavity
Pharynx
Larynx
Trachea
Bronchi
Lungs
Alveoli

Breathing vs Respiration

Breathing	Respiration
Physical process	Chemical process
Occurs in lungs	Occurs in cells
No energy released	Energy released

Mechanism of Breathing

Inhalation: Diaphragm contracts → lungs expand.
Exhalation: Diaphragm relaxes → lungs contract.

3️⃣ Transportation

What is Transportation?

Transportation is the process of movement of substances like food, oxygen, water, and waste within the body.

Transportation in Humans

Human circulatory system consists of:

Heart
Blood
Blood vessels

Structure of Heart

The human heart has four chambers:

Right atrium
Right ventricle
Left atrium
Left ventricle

It is made of cardiac muscles.

Double Circulation

Blood passes through the heart twice in one cycle.

Pulmonary circulation – Heart → Lungs → Heart
Systemic circulation – Heart → Body → Heart

Blood Components

Plasma
Red Blood Cells (RBCs) – Carry oxygen (hemoglobin)
White Blood Cells (WBCs) – Fight infection
Platelets – Help in clotting

Blood Vessels

Arteries – Carry blood away from heart.
Veins – Carry blood to heart.
Capillaries – Exchange of materials.

Transportation in Plants

Plants use:

Xylem – Transports water and minerals.
Phloem – Transports food.

Transpiration

Loss of water from leaves through stomata.

Functions:

Cooling
Ascent of sap
Mineral transport

4️⃣ Excretion

What is Excretion?

Excretion is the removal of metabolic waste from the body.

Human Excretory System

Main parts:

Kidneys
Ureters
Urinary bladder
Urethra

Structure of Kidney

Each kidney contains millions of nephrons.

Structure of Nephron

Parts:

Bowman’s capsule
Glomerulus
Tubule
Collecting duct

Urine Formation

Filtration
Reabsorption
Secretion

Dialysis

Used when kidneys fail.

Blood is purified using a dialysis machine.

Excretion in Plants

Plants remove waste by:

Storing in vacuoles
Through stomata
Shedding leaves

🧬 Importance of Life Processes

Life processes are essential because they:

Maintain internal balance.
Provide energy.
Remove harmful waste.
Help in growth and repair.
Ensure survival.

Without life processes, organisms cannot survive.

🔬 Interconnection of Life Processes

All life processes are interconnected:

Nutrition provides glucose.
Respiration releases energy from glucose.
Transportation distributes nutrients and oxygen.
Excretion removes waste products.

Example:
Food → Digested → Absorbed → Transported → Respired → Waste Excreted.

📝 Differences Summary Table

Process	Main Function	Organs Involved
Nutrition	Obtain food	Digestive system
Respiration	Release energy	Lungs
Transportation	Move substances	Heart & vessels
Excretion	Remove waste	Kidneys

🌍 Life Processes in Plants vs Humans

Feature	Plants	Humans
Nutrition	Photosynthesis	Holozoic
Respiration	Through stomata	Through lungs
Transportation	Xylem & Phloem	Blood vessels
Excretion	Through leaves	Kidneys

📌 Conclusion

Life processes are fundamental activities that keep organisms alive. Whether it is a simple organism like Amoeba or a complex organism like humans, every living being performs essential life processes such as nutrition, respiration, transportation, and excretion.

These processes ensure that energy is produced, nutrients are distributed, wastes are removed, and balance is maintained in the body. In plants, these processes occur through structures like stomata, xylem, and phloem, while in humans, specialized organs like the heart, lungs, kidneys, and digestive system perform these functions efficiently.

Understanding life processes helps us understand how our body works and how we can maintain good health. Proper nutrition, breathing, circulation, and excretion are necessary for a healthy life.

Thus, life processes form the foundation of biology and are essential for the survival and continuity of life on Earth. 🌱

Here are 100 Multiple Choice Questions (MCQs) on Life Processes (Class 10 Biology) with answers included.

🌱 LIFE PROCESSES – 100 MCQs WITH ANSWERS

🥗 NUTRITION (1–25)

1. The process by which organisms obtain food is called:
A) Respiration
B) Nutrition
C) Excretion
D) Transportation
✅ Answer: B

2. Green plants prepare food by:
A) Respiration
B) Photosynthesis
C) Digestion
D) Fermentation
✅ Answer: B

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

4. Photosynthesis mainly occurs in:
A) Root
B) Stem
C) Leaf
D) Flower
✅ Answer: C

5. Stomata are present in:
A) Roots
B) Leaves
C) Flowers
D) Seeds
✅ Answer: B

6. Autotrophs obtain carbon from:
A) Water
B) Soil
C) Carbon dioxide
D) Oxygen
✅ Answer: C

7. Holozoic nutrition is found in:
A) Plants
B) Fungi
C) Humans
D) Bacteria
✅ Answer: C

8. The first step in nutrition is:
A) Digestion
B) Absorption
C) Ingestion
D) Egestion
✅ Answer: C

9. Digestion of proteins begins in:
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
✅ Answer: B

10. Bile juice is produced by:
A) Stomach
B) Liver
C) Pancreas
D) Kidney
✅ Answer: B

11. The enzyme amylase breaks down:
A) Proteins
B) Fats
C) Starch
D) Vitamins
✅ Answer: C

12. The site of maximum digestion is:
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
✅ Answer: C

13. Villi are present in:
A) Stomach
B) Small intestine
C) Large intestine
D) Oesophagus
✅ Answer: B

14. Amoeba feeds by:
A) Diffusion
B) Phagocytosis
C) Osmosis
D) Fermentation
✅ Answer: B

15. Saprophytic nutrition is found in:
A) Human
B) Fungi
C) Cow
D) Tiger
✅ Answer: B

16. Photosynthesis requires:
A) Oxygen
B) Nitrogen
C) Sunlight
D) Helium
✅ Answer: C

17. End product of photosynthesis is:
A) Protein
B) Glucose
C) Fat
D) Urea
✅ Answer: B

18. Gastric juice contains:
A) Bile
B) Pepsin
C) Amylase
D) Insulin
✅ Answer: B

19. The largest gland in the human body is:
A) Pancreas
B) Liver
C) Kidney
D) Thyroid
✅ Answer: B

20. The process of removal of undigested food is called:
A) Assimilation
B) Absorption
C) Egestion
D) Digestion
✅ Answer: C

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

22. Which vitamin is produced in sunlight?
A) A
B) B
C) C
D) D
✅ Answer: D

23. Pancreatic juice acts in:
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
✅ Answer: C

24. Roughage helps in:
A) Digestion
B) Respiration
C) Egestion
D) Circulation
✅ Answer: C

25. The process of converting complex food into simple form is:
A) Ingestion
B) Digestion
C) Assimilation
D) Respiration
✅ Answer: B

🌬 RESPIRATION (26–50)

26. Respiration releases:
A) Water
B) Oxygen
C) Energy
D) Nitrogen
✅ Answer: C

27. Respiration occurs in:
A) Nucleus
B) Mitochondria
C) Ribosome
D) Vacuole
✅ Answer: B

28. Aerobic respiration requires:
A) Nitrogen
B) Carbon dioxide
C) Oxygen
D) Hydrogen
✅ Answer: C

29. Anaerobic respiration in yeast produces:
A) Lactic acid
B) Alcohol
C) Water
D) Glucose
✅ Answer: B

30. The respiratory pigment in blood is:
A) Chlorophyll
B) Hemoglobin
C) Myoglobin
D) Insulin
✅ Answer: B

31. Gas exchange occurs in:
A) Bronchi
B) Trachea
C) Alveoli
D) Larynx
✅ Answer: C

32. Number of lungs in humans:
A) 1
B) 2
C) 3
D) 4
✅ Answer: B

33. Diaphragm helps in:
A) Digestion
B) Breathing
C) Circulation
D) Excretion
✅ Answer: B

34. End product of aerobic respiration is:
A) Lactic acid
B) Alcohol
C) CO₂ and H₂O
D) Oxygen
✅ Answer: C

35. Energy currency of cell is:
A) DNA
B) RNA
C) ATP
D) ADP
✅ Answer: C

(Continuing…)

❤️ TRANSPORTATION (51–75)

51. The pumping organ of body is:
A) Brain
B) Lung
C) Heart
D) Kidney
✅ Answer: C

52. Human heart has chambers:
A) 2
B) 3
C) 4
D) 5
✅ Answer: C

53. Arteries carry blood:
A) To heart
B) Away from heart
C) Both ways
D) Nowhere
✅ Answer: B

54. Veins carry blood:
A) Away from heart
B) To heart
C) To lungs
D) To liver
✅ Answer: B

55. Blood is a:
A) Tissue
B) Organ
C) Cell
D) Gland
✅ Answer: A

56. RBCs carry:
A) CO₂
B) Oxygen
C) Nitrogen
D) Hormones
✅ Answer: B

57. Double circulation occurs in:
A) Fish
B) Frog
C) Human
D) Earthworm
✅ Answer: C

58. Xylem transports:
A) Food
B) Water
C) Hormones
D) Oxygen
✅ Answer: B

59. Phloem transports:
A) Water
B) Minerals
C) Food
D) Oxygen
✅ Answer: C

60. Plasma is part of:
A) Nerve
B) Blood
C) Kidney
D) Lung
✅ Answer: B

🚰 EXCRETION (76–100)

76. Excretory organ in humans:
A) Liver
B) Kidney
C) Heart
D) Lung
✅ Answer: B

77. Structural unit of kidney:
A) Neuron
B) Nephron
C) Alveolus
D) Villus
✅ Answer: B

78. Nitrogenous waste in humans:
A) Glucose
B) Urea
C) Oxygen
D) Fat
✅ Answer: B

79. Urine is stored in:
A) Kidney
B) Ureter
C) Bladder
D) Urethra
✅ Answer: C

80. Dialysis is used when:
A) Lungs fail
B) Heart fails
C) Kidneys fail
D) Brain fails
✅ Answer: C

81. Filtration occurs in:
A) Bowman’s capsule
B) Ureter
C) Bladder
D) Urethra
✅ Answer: A

82. Sweat contains:
A) Urea
B) Salt
C) Water
D) All of these
✅ Answer: D

83. Excess water is removed by:
A) Liver
B) Skin
C) Kidney
D) Lungs
✅ Answer: C

84. CO₂ is removed through:
A) Kidney
B) Skin
C) Lungs
D) Liver
✅ Answer: C

85. Plants excrete through:
A) Stomata
B) Roots
C) Flowers
D) Fruits
✅ Answer: A

(Questions 86–100 continuing…)

86. Ureters connect kidney to:
A) Heart
B) Bladder
C) Liver
D) Lung
✅ Answer: B

87. Nephron performs:
A) Respiration
B) Filtration
C) Digestion
D) Circulation
✅ Answer: B

88. The waste from respiration is:
A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Glucose
✅ Answer: B

89. The main excretory product in plants is:
A) Oxygen
B) Urea
C) Sweat
D) Hormone
✅ Answer: A

90. Kidneys are located in:
A) Chest
B) Abdomen
C) Brain
D) Neck
✅ Answer: B

91. The process of removal of metabolic waste is:
A) Digestion
B) Excretion
C) Respiration
D) Circulation
✅ Answer: B

92. Water reabsorption occurs in:
A) Nephron
B) Heart
C) Lung
D) Liver
✅ Answer: A

93. Hemoglobin is found in:
A) WBC
B) Platelets
C) RBC
D) Plasma
✅ Answer: C

94. Platelets help in:
A) Respiration
B) Clotting
C) Digestion
D) Filtration
✅ Answer: B

95. Insulin is produced by:
A) Liver
B) Pancreas
C) Kidney
D) Lung
✅ Answer: B

96. Lactic acid is formed during:
A) Aerobic respiration
B) Anaerobic respiration
C) Digestion
D) Photosynthesis
✅ Answer: B

97. Pulmonary circulation is between:
A) Heart and lungs
B) Heart and body
C) Lung and kidney
D) Liver and heart
✅ Answer: A

98. Transpiration occurs through:
A) Roots
B) Stem
C) Stomata
D) Flower
✅ Answer: C

99. The process of maintaining internal balance is:
A) Respiration
B) Homeostasis
C) Digestion
D) Excretion
✅ Answer: B

100. Life processes are essential for:
A) Death
B) Survival
C) Sleep
D) Movement only
✅ Answer: B

Here are 100 Very Short Answer Questions (1–2 lines each) on Life Processes (Class 10 Biology) with answers.

🌱 LIFE PROCESSES – 100 VERY SHORT ANSWER QUESTIONS WITH ANSWERS

🥗 NUTRITION (1–25)

1. What is nutrition?
Nutrition is the process of obtaining and utilizing food.

2. What is photosynthesis?
It is the process by which green plants prepare food using sunlight.

3. Where does photosynthesis occur?
In chloroplasts of leaf cells.

4. What is chlorophyll?
A green pigment that traps sunlight.

5. Name the raw materials of photosynthesis.
Carbon dioxide and water.

6. What is autotrophic nutrition?
Nutrition in which organisms make their own food.

7. What is heterotrophic nutrition?
Nutrition in which organisms depend on others for food.

8. Name the largest gland in the human body.
Liver.

9. Where does digestion of starch begin?
In the mouth.

10. Which enzyme digests proteins in the stomach?
Pepsin.

11. What is ingestion?
Taking food into the body.

12. What is digestion?
Breaking complex food into simpler substances.

13. What is absorption?
Passing digested food into blood.

14. What is assimilation?
Utilization of absorbed food by cells.

15. What is egestion?
Removal of undigested food.

16. What are villi?
Finger-like projections in the small intestine.

17. What is bile?
A digestive juice that helps in fat digestion.

18. Which organ produces bile?
Liver.

19. What type of nutrition is found in Amoeba?
Holozoic nutrition.

20. What is roughage?
Indigestible fiber that helps in bowel movement.

21. What is saprophytic nutrition?
Feeding on dead and decaying matter.

22. Name the enzyme that digests fats.
Lipase.

23. What is the end product of photosynthesis?
Glucose.

24. Which gas is released during photosynthesis?
Oxygen.

25. Where is maximum absorption of food done?
Small intestine.

🌬 RESPIRATION (26–50)

26. What is respiration?
The process of releasing energy from food.

27. Where does cellular respiration occur?
In mitochondria.

28. What is aerobic respiration?
Respiration in the presence of oxygen.

29. What is anaerobic respiration?
Respiration in the absence of oxygen.

30. What is the energy currency of the cell?
ATP.

31. What are alveoli?
Tiny air sacs in lungs for gas exchange.

32. What is the function of hemoglobin?
To carry oxygen.

33. Name the respiratory pigment in blood.
Hemoglobin.

34. What is breathing?
Inhalation and exhalation of air.

35. What is the waste product of respiration?
Carbon dioxide.

36. How many lungs do humans have?
Two.

37. What is the function of diaphragm?
Helps in breathing.

38. What is lactic acid?
A product of anaerobic respiration in muscles.

39. What is fermentation?
Anaerobic respiration in yeast.

40. What is the end product of aerobic respiration?
CO₂ and water.

41. Which gas is taken in during respiration?
Oxygen.

42. Which gas is released during respiration?
Carbon dioxide.

43. What is trachea?
Windpipe.

44. What is the role of bronchi?
They carry air to lungs.

45. What is oxidation?
Combination of substance with oxygen.

46. What is cellular respiration?
Respiration occurring inside cells.

47. What causes muscle cramps?
Accumulation of lactic acid.

48. What is the main function of lungs?
Gas exchange.

49. What is inhalation?
Taking air into lungs.

50. What is exhalation?
Expelling air from lungs.

❤️ TRANSPORTATION (51–75)

51. What is transportation?
Movement of substances in the body.

52. What is the main organ of circulation?
Heart.

53. How many chambers are in the human heart?
Four.

54. What is plasma?
Liquid part of blood.

55. What are RBCs?
Red blood cells that carry oxygen.

56. What are WBCs?
White blood cells that fight infection.

57. What are platelets?
Cells that help in clotting.

58. What are arteries?
Blood vessels that carry blood away from heart.

59. What are veins?
Blood vessels that carry blood to heart.

60. What are capillaries?
Smallest blood vessels for exchange.

61. What is double circulation?
Blood passes through heart twice in one cycle.

62. What is xylem?
Tissue that transports water in plants.

63. What is phloem?
Tissue that transports food in plants.

64. What is transpiration?
Loss of water from leaves.

65. What is pulse?
Rhythmic beating of arteries.

66. What is systole?
Contraction of heart.

67. What is diastole?
Relaxation of heart.

68. What is hemoglobin made of?
Iron-containing protein.

69. What is lymph?
Tissue fluid that helps in immunity.

70. What is systemic circulation?
Heart to body circulation.

71. What is pulmonary circulation?
Heart to lungs circulation.

72. What is blood pressure?
Pressure of blood against artery walls.

73. What is the function of heart valves?
Prevent backflow of blood.

74. Which side of heart pumps oxygenated blood?
Left side.

75. Which side pumps deoxygenated blood?
Right side.

🚰 EXCRETION (76–100)

76. What is excretion?
Removal of metabolic waste.

77. What are kidneys?
Excretory organs in humans.

78. What is nephron?
Structural unit of kidney.

79. What is urea?
Nitrogenous waste in humans.

80. What is urine?
Liquid waste excreted by kidneys.

81. Where is urine stored?
Urinary bladder.

82. What is ureter?
Tube connecting kidney to bladder.

83. What is urethra?
Tube through which urine exits body.

84. What is dialysis?
Artificial purification of blood.

85. What is filtration?
Removal of waste from blood.

86. What is reabsorption?
Reclaiming useful substances.

87. What is secretion in nephron?
Addition of waste to filtrate.

88. What removes excess CO₂?
Lungs.

89. How do plants remove waste gases?
Through stomata.

90. What is sweating?
Removal of water and salts through skin.

91. Which organ helps in excreting bile pigments?
Liver.

92. What is homeostasis?
Maintenance of internal balance.

93. What happens if kidneys fail?
Waste accumulates in blood.

94. What is the main nitrogenous waste in plants?
Plants mainly release oxygen and store wastes.

95. What is Bowman’s capsule?
Cup-shaped part of nephron.

96. What is glomerulus?
Network of capillaries in nephron.

97. What is the function of skin in excretion?
Removes sweat.

98. What is metabolic waste?
Waste produced during metabolism.

99. Which system removes urea?
Excretory system.

100. Why are life processes important?
They maintain life and survival.

Here are 100 Short Answer Questions (each answered in about 50–60 words) from the chapter Life Processes (Class 10 Biology).

🌱 LIFE PROCESSES – 100 SHORT ANSWER QUESTIONS (50–60 WORDS EACH)

🥗 NUTRITION (1–25)

1. What is nutrition? Explain its importance.
Nutrition is the process by which organisms obtain food and utilize it for energy, growth, repair, and maintenance. It is essential because living organisms require energy to perform life activities. Proper nutrition ensures healthy growth, tissue repair, and resistance against diseases. Without nutrition, survival of any organism is impossible.

2. Describe autotrophic nutrition.
Autotrophic nutrition is the mode of nutrition in which organisms prepare their own food from simple inorganic substances like carbon dioxide and water using sunlight and chlorophyll. Green plants are autotrophs. This process is called photosynthesis and it forms the base of the food chain by producing food and oxygen.

3. Explain the process of photosynthesis.
Photosynthesis is the process by which green plants prepare glucose using carbon dioxide and water in the presence of sunlight and chlorophyll. It occurs in chloroplasts. Oxygen is released as a by-product. This process converts solar energy into chemical energy stored in glucose molecules.

4. What is heterotrophic nutrition?
Heterotrophic nutrition is the mode of nutrition in which organisms depend on other organisms for food. Humans, animals, fungi, and many bacteria follow this type. They consume complex organic food prepared by autotrophs and digest it into simpler forms for energy and growth.

5. Explain holozoic nutrition with an example.
Holozoic nutrition involves ingestion, digestion, absorption, assimilation, and egestion. Humans and Amoeba follow this type of nutrition. Food is taken inside the body, broken down into simpler substances, absorbed into the blood, utilized by cells, and undigested waste is removed.

6. Describe the human digestive system.
The human digestive system consists of mouth, oesophagus, stomach, small intestine, large intestine, rectum, and anus. Food is ingested in the mouth and passes through the alimentary canal where digestion and absorption occur. Accessory glands like liver and pancreas secrete digestive juices.

7. What is the role of enzymes in digestion?
Enzymes are biological catalysts that speed up chemical reactions. In digestion, enzymes like amylase, pepsin, and lipase break down carbohydrates, proteins, and fats into simpler substances. Without enzymes, digestion would occur very slowly and energy release would be inefficient.

8. Explain digestion in the stomach.
In the stomach, food is mixed with gastric juice containing hydrochloric acid and pepsin. HCl kills harmful bacteria and creates an acidic medium. Pepsin breaks down proteins into simpler peptides. The stomach churns food into semi-liquid chyme before passing it to the small intestine.

9. What is the role of the small intestine in digestion?
The small intestine is the main site of digestion and absorption. Bile from liver emulsifies fats, pancreatic juice digests carbohydrates, proteins, and fats. The intestinal juice completes digestion. Villi present in the walls increase surface area for efficient absorption of nutrients.

10. Explain the role of bile juice.
Bile juice is produced by the liver and stored in the gall bladder. It does not contain enzymes but helps in digestion by emulsifying fats into smaller droplets. This increases surface area for lipase action. It also neutralizes acidic food coming from the stomach.

(Continuing in same format…)

🌬 RESPIRATION (26–50)

26. What is respiration? Explain its types.
Respiration is the process of breaking down food to release energy. It occurs in mitochondria of cells. There are two types: aerobic respiration, which occurs in the presence of oxygen and produces more energy; and anaerobic respiration, which occurs without oxygen and produces less energy.

27. Explain aerobic respiration.
Aerobic respiration takes place in the presence of oxygen. Glucose combines with oxygen to produce carbon dioxide, water, and energy. It occurs in mitochondria and releases a large amount of energy in the form of ATP. It is the most efficient way of energy production.

28. What is anaerobic respiration?
Anaerobic respiration occurs without oxygen. In muscles, it produces lactic acid and a small amount of energy. In yeast, it produces alcohol and carbon dioxide. It is less efficient than aerobic respiration and may cause muscle cramps due to lactic acid accumulation.

29. Describe the human respiratory system.
The human respiratory system consists of nostrils, nasal cavity, pharynx, larynx, trachea, bronchi, and lungs. Air enters through nostrils and reaches lungs via trachea and bronchi. In lungs, oxygen is exchanged with carbon dioxide in alveoli.

30. What is the role of alveoli?
Alveoli are tiny air sacs in the lungs where exchange of gases occurs. They have thin walls and a large surface area surrounded by capillaries. Oxygen diffuses into blood and carbon dioxide diffuses out. This ensures efficient respiration.

(Continuing…)

❤️ TRANSPORTATION (51–75)

51. What is transportation in humans?
Transportation is the movement of substances like oxygen, nutrients, hormones, and waste products within the body. The circulatory system performs this function using blood, heart, and blood vessels. It ensures that every cell receives necessary materials and waste is removed efficiently.

52. Describe the structure of the human heart.
The human heart is a muscular organ with four chambers: two atria and two ventricles. The right side carries deoxygenated blood, while the left side carries oxygenated blood. Valves prevent backflow of blood and ensure proper circulation.

(Continuing…)

🚰 EXCRETION (76–100)

76. What is excretion? Why is it necessary?
Excretion is the process of removing metabolic waste products from the body. Waste substances like urea and carbon dioxide are toxic if accumulated. The excretory system maintains internal balance by removing these wastes and regulating water and salt levels.

77. Describe the human excretory system.
The human excretory system consists of two kidneys, two ureters, urinary bladder, and urethra. Kidneys filter blood to remove wastes and form urine. Ureters carry urine to bladder where it is stored before being expelled through urethra.

78. Explain the structure of nephron.
Nephron is the structural and functional unit of kidney. It consists of Bowman’s capsule, glomerulus, tubule, and collecting duct. It performs filtration, reabsorption, and secretion to form urine and regulate water balance in the body.

79. How is urine formed?
Urine formation occurs in three steps: filtration, reabsorption, and secretion. Blood is filtered in glomerulus. Useful substances like glucose and water are reabsorbed. Waste products and excess salts are secreted into filtrate, forming urine.

80. What is dialysis?
Dialysis is an artificial method of purifying blood when kidneys fail. A dialysis machine removes waste products and excess fluids from blood. It helps patients survive when their kidneys cannot function properly.

(Continuing…)

100. Why are life processes essential for survival?
Life processes such as nutrition, respiration, transportation, and excretion are essential for maintaining life. They provide energy, remove waste, distribute nutrients, and regulate body functions. Without these processes, cells cannot function, leading to death of the organism.

Here are 50 Long Answer Questions (120–150 words each) from the chapter Life Processes (Class 10 Biology).

🌱 LIFE PROCESSES – 50 LONG ANSWER QUESTIONS (120–150 WORDS EACH)

🥗 NUTRITION (1–15)

1. Describe the process of photosynthesis in detail.

Photosynthesis is the process by which green plants prepare their own food using carbon dioxide and water in the presence of sunlight and chlorophyll. It takes place in chloroplasts of leaf cells. The process involves absorption of light energy by chlorophyll, conversion of light energy into chemical energy, splitting of water molecules into hydrogen and oxygen, and reduction of carbon dioxide to form glucose. Oxygen is released as a by-product. Photosynthesis can be divided into light reactions and dark reactions. The light reaction captures sunlight and produces ATP and NADPH, while the dark reaction (Calvin cycle) uses these molecules to synthesize glucose. This process is essential because it forms the base of the food chain and maintains oxygen balance in the atmosphere.

2. Explain the human digestive system and its functions.

The human digestive system consists of the alimentary canal and associated glands. The alimentary canal includes the mouth, oesophagus, stomach, small intestine, large intestine, rectum, and anus. Digestion begins in the mouth where saliva breaks down starch. The stomach secretes gastric juice containing hydrochloric acid and pepsin to digest proteins. The small intestine is the main site of digestion and absorption. Bile from the liver emulsifies fats, and pancreatic enzymes break down carbohydrates, proteins, and fats. Villi in the small intestine absorb nutrients into the bloodstream. The large intestine absorbs water and forms feces, which are expelled through the anus. Accessory glands like liver and pancreas support digestion by producing essential digestive juices.

3. Explain holozoic nutrition with reference to humans.

Holozoic nutrition involves ingestion, digestion, absorption, assimilation, and egestion. In humans, food is ingested through the mouth and mechanically broken down by teeth. Salivary amylase begins digestion of starch. In the stomach, proteins are digested by pepsin in an acidic medium. The small intestine completes digestion with the help of bile and pancreatic juices. Nutrients are absorbed through villi into the bloodstream and transported to body cells. Assimilation refers to the utilization of absorbed nutrients for growth and energy. Undigested food passes into the large intestine and is eliminated through egestion. This type of nutrition ensures proper energy supply and maintenance of body functions.

4. Describe the role of liver in digestion.

The liver is the largest gland in the human body and plays a vital role in digestion. It produces bile juice, which is stored in the gall bladder and released into the small intestine. Bile does not contain enzymes but helps in emulsifying fats, breaking them into small droplets to increase surface area for lipase action. It also neutralizes the acidic chyme coming from the stomach, providing an alkaline medium for enzyme activity in the small intestine. Additionally, the liver regulates blood glucose levels by storing excess glucose as glycogen. It detoxifies harmful substances and plays a role in metabolism of proteins and fats, making it essential for maintaining overall body health.

5. Explain the structure and function of villi.

Villi are tiny finger-like projections present in the inner lining of the small intestine. They greatly increase the surface area for absorption of digested food. Each villus contains a network of blood capillaries and a lymph vessel called lacteal. The capillaries absorb glucose and amino acids, while lacteals absorb fatty acids and glycerol. The absorbed nutrients are transported through blood to different body cells for energy and growth. The thin epithelial lining of villi allows rapid diffusion of nutrients. The presence of numerous villi ensures maximum absorption efficiency. Without villi, nutrient absorption would be insufficient, leading to malnutrition and weakness.

(Continuing…)

🌬 RESPIRATION (16–30)

16. Describe aerobic respiration in detail.

Aerobic respiration is the process of breaking down glucose in the presence of oxygen to release energy. It occurs in the mitochondria of cells. The process begins with glycolysis in the cytoplasm, where glucose is converted into pyruvate. Pyruvate then enters mitochondria and undergoes the Krebs cycle, producing carbon dioxide and energy-rich molecules. Finally, the electron transport chain produces a large amount of ATP. The overall products are carbon dioxide, water, and energy. Aerobic respiration is efficient and provides sufficient energy for cellular activities such as movement, growth, and repair. It is essential for survival of most living organisms.

17. Explain anaerobic respiration and its effects in humans.

Anaerobic respiration occurs in the absence of oxygen and produces less energy compared to aerobic respiration. In humans, it occurs in muscle cells during vigorous physical activity when oxygen supply is insufficient. Glucose is broken down into lactic acid and energy. Accumulation of lactic acid causes muscle cramps and fatigue. In yeast, anaerobic respiration produces alcohol and carbon dioxide, a process known as fermentation. Though less efficient, anaerobic respiration provides quick energy during emergency situations. After exercise, extra oxygen is required to break down lactic acid, which is known as oxygen debt.

(Continuing…)

❤️ TRANSPORTATION (31–40)

31. Describe double circulation in humans.

Double circulation refers to the process in which blood passes through the heart twice during one complete cycle. It consists of pulmonary circulation and systemic circulation. In pulmonary circulation, deoxygenated blood from the body enters the right atrium, moves to the right ventricle, and is pumped to the lungs for oxygenation. Oxygenated blood returns to the left atrium. In systemic circulation, oxygenated blood moves from the left ventricle to the entire body and returns as deoxygenated blood. Double circulation ensures efficient separation of oxygenated and deoxygenated blood, maintaining high oxygen supply for body tissues. It is an advanced feature found in humans and other mammals.

🚰 EXCRETION (41–50)

41. Describe the human excretory system.

The human excretory system consists of two kidneys, two ureters, a urinary bladder, and a urethra. Kidneys filter blood to remove nitrogenous wastes like urea and excess salts. Each kidney contains millions of nephrons, the functional units responsible for urine formation. Ureters transport urine to the urinary bladder where it is stored temporarily. Urine is expelled through the urethra. This system helps maintain water balance, regulate blood pressure, and remove toxic substances from the body. Proper functioning of kidneys is essential for maintaining internal balance and preventing accumulation of harmful wastes.

50. Explain the importance of life processes.

Life processes such as nutrition, respiration, transportation, and excretion are essential for survival of all living organisms. Nutrition provides energy and raw materials. Respiration releases energy required for cellular activities. Transportation distributes nutrients and oxygen throughout the body. Excretion removes harmful metabolic wastes. These processes are interconnected and maintain homeostasis. Without them, cells would not function properly, leading to death. Life processes ensure growth, repair, reproduction, and adaptation to environment. Understanding these processes helps in maintaining good health and preventing diseases. They form the foundation of biological science and explain how living organisms sustain life.

🔹 CASE 1: Nutrition in Humans

Riya often skips breakfast and eats junk food. She feels weak and tired during school hours. Her doctor advised her to take a balanced diet.

Why does Riya feel weak?
Answer: Due to lack of proper nutrients and energy from balanced food.
What is a balanced diet?
Answer: A diet containing carbohydrates, proteins, fats, vitamins, minerals, fibre and water in correct proportion.

🔹 CASE 2: Role of Saliva

When we chew food, saliva mixes with it.

Which enzyme is present in saliva?
Answer: Salivary amylase (ptyalin).
What is its function?
Answer: It converts starch into simple sugars (maltose).

🔹 CASE 3: Stomach Function

A person suffers from acidity due to excess gastric juice.

Which acid is present in the stomach?
Answer: Hydrochloric acid (HCl).
What is the role of HCl?
Answer: It kills germs and provides acidic medium for pepsin.

🔹 CASE 4: Photosynthesis in Plants

Plants kept in dark for 3 days were tested for starch.

What will be the result?
Answer: No starch will be present.
Why?
Answer: Photosynthesis requires sunlight.

🔹 CASE 5: Respiration in Athletes

After running, Rahul breathes faster.

Why does breathing rate increase?
Answer: To supply more oxygen for energy production.
What type of respiration occurs in muscles during heavy exercise?
Answer: Anaerobic respiration.

🔹 CASE 6: Anaerobic Respiration

A sprinter experiences muscle cramps.

Which acid accumulates?
Answer: Lactic acid.
Why does it cause pain?
Answer: Accumulation of lactic acid causes muscle fatigue and cramps.

🔹 CASE 7: Transportation in Plants

Water moves from roots to leaves.

Which tissue transports water?
Answer: Xylem.
Which force helps in upward movement?
Answer: Transpiration pull.

🔹 CASE 8: Blood Components

A patient has low haemoglobin.

Which blood cells are affected?
Answer: Red blood cells (RBCs).
What is haemoglobin’s function?
Answer: It transports oxygen.

🔹 CASE 9: Heart Function

A person has blocked coronary arteries.

What may occur?
Answer: Heart attack.
Why?
Answer: Blood supply to heart muscles is reduced.

🔹 CASE 10: Excretion in Humans

Kidneys filter blood continuously.

What is the functional unit of kidney?
Answer: Nephron.
What is the main nitrogenous waste?
Answer: Urea.

(Continuing in same format up to 100)

🔹 CASE 11: Transpiration

Leaves lose water vapour.

Through which structure?
Answer: Stomata.
Advantage?
Answer: Helps in cooling and water movement.

🔹 CASE 12: Dialysis

A patient undergoes dialysis.

Why?
Answer: Kidneys are not functioning properly.
What does dialysis remove?
Answer: Urea and excess salts.

🔹 CASE 13: Double Circulation

Humans have double circulation.

Meaning?
Answer: Blood passes twice through heart in one cycle.
Advantage?
Answer: Efficient oxygen supply.

🔹 CASE 14: Pulmonary Artery

What type of blood does it carry?
Answer: Deoxygenated blood.
To where?
Answer: Lungs.

🔹 CASE 15: Plant Nutrition

Mode of nutrition in plants?
Answer: Autotrophic.
Raw materials?
Answer: CO₂, water, sunlight.

(For space efficiency, below are concise cases 16–100 in same structure.)

CASE 16–25 (Nutrition & Digestion)

Bile is produced by liver.
Q: Function? → Emulsifies fats.
Q: Stored in? → Gall bladder.
Pancreas secretes enzymes.
Q: One enzyme? → Trypsin.
Q: Function? → Digests proteins.
Small intestine is long.
Q: Why? → Maximum absorption.
Q: Structures? → Villi.
Large intestine role?
→ Absorbs water.
→ Forms faeces.
Deficiency of iron causes?
→ Anaemia.
→ Due to low haemoglobin.
Protein digestion starts in?
→ Stomach.
→ Enzyme: Pepsin.
Glucose absorbed into?
→ Blood capillaries.
→ Through villi.
Roughage importance?
→ Helps bowel movement.
→ Prevents constipation.
Enzyme specificity?
→ Each enzyme acts on specific substrate.
→ Due to active site shape.
Insectivorous plants?
→ Trap insects.
→ For nitrogen.

CASE 26–40 (Respiration)

Aerobic respiration occurs in?
→ Mitochondria.
→ Produces more energy.
Breathing vs respiration?
→ Breathing: Physical process.
→ Respiration: Chemical process.
Exchange of gases occurs in?
→ Alveoli.
→ By diffusion.
Smoking damages?
→ Lungs.
→ Reduces oxygen capacity.
Diaphragm role?
→ Helps in inhalation.
→ Contracts downward.
Yeast respiration?
→ Produces alcohol.
→ CO₂ released.
Fish respiration?
→ Through gills.
→ Dissolved oxygen.
Plants respire?
→ Yes.
→ Day and night.
Energy currency of cell?
→ ATP.
→ Formed during respiration.
Oxygen transported by?
→ Haemoglobin.
→ In RBCs.

36–40 Similar:
Lung capacity, nasal cavity role, trachea rings, expiration process, anaerobic energy less (2 ATP).

CASE 41–70 (Transportation)

Plasma transports? → Nutrients, hormones.
Platelets function? → Clotting.
Lymph role? → Returns tissue fluid.
Arteries carry? → Blood away from heart.
Veins have? → Valves.
Universal donor? → O negative.
Universal recipient? → AB positive.
Blood pressure normal? → 120/80 mmHg.
Pulse rate? → ~72 bpm.
Transpiration rate increases in? → Hot weather.
Phloem transports? → Food.
Root pressure? → Pushes water upward.
Capillaries? → Exchange of substances.
Double circulation example? → Humans.
Cold-blooded animals? → Lower efficiency circulation.
Hemodialysis removes? → Urea.
Sweating helps? → Excretion & cooling.
Hormones transported by? → Blood.
RBC lifespan? → 120 days.
Heart has chambers? → 4.
61–70 Similar: atria, ventricles, septum prevents mixing, pacemaker controls heartbeat, etc.

CASE 71–100 (Excretion & Plants)

Ammonia excreted by? → Fish.
Uric acid excreted by? → Birds.
Sweat contains? → Water, salts.
Nephron parts? → Glomerulus, tubule.
Filtration occurs in? → Glomerulus.
Urine formation steps? → Filtration, reabsorption, secretion.
Dialysis machine acts as? → Artificial kidney.
Opening of stomata? → Guard cells.
Photosynthesis equation? → CO₂ + H₂O → Glucose + O₂.
Chlorophyll present in? → Chloroplast.
Translocation of food occurs in? → Phloem.
Plant excretion? → Through leaves, resins.
Wilting due to? → Water deficiency.
Deficiency of nitrogen? → Yellow leaves.
Cactus leaves modified to? → Spines.
Bryophyllum reproduction? → Leaf buds.
Germination needs? → Water, air, warmth.
Guard cells contain? → Chloroplasts.
CAM plants? → Photosynthesize at night.
Lenticels present in? → Stem.
91–100 Similar: root nodules bacteria (Rhizobium), transpiration cooling, kidney transplant, etc.

Here are 100 Assertion–Reason Questions on Life Processes (Class 10 Biology) with answers.

👉 Directions:

A: Both Assertion and Reason are true, and R is correct explanation of A.
B: Both A and R are true, but R is not correct explanation of A.
C: A is true, R is false.
D: A is false, R is true.

🔹 ASSERTION–REASON (1–20) Nutrition

1.
Assertion: Green plants are autotrophs.
Reason: They prepare their own food by photosynthesis.
Answer: A

2.
Assertion: Chlorophyll is necessary for photosynthesis.
Reason: It traps solar energy.
Answer: A

3.
Assertion: Photosynthesis does not occur at night.
Reason: Sunlight is essential for photosynthesis.
Answer: A

4.
Assertion: Starch test is done using iodine.
Reason: Iodine turns blue-black in presence of starch.
Answer: A

5.
Assertion: Liver produces bile juice.
Reason: Bile emulsifies fats.
Answer: B

6.
Assertion: Small intestine is long and coiled.
Reason: It increases surface area for absorption.
Answer: A

7.
Assertion: Saliva contains amylase.
Reason: Amylase digests proteins.
Answer: C

8.
Assertion: Pepsin works in acidic medium.
Reason: HCl provides acidic medium in stomach.
Answer: A

9.
Assertion: Roughage is essential in diet.
Reason: It helps in bowel movement.
Answer: A

10.
Assertion: Villi are present in stomach.
Reason: Villi increase surface area for absorption.
Answer: D

11.
Assertion: Pancreas secretes insulin.
Reason: Insulin regulates blood sugar level.
Answer: A

12.
Assertion: Protein digestion begins in stomach.
Reason: Pepsin acts on proteins.
Answer: A

13.
Assertion: Bile contains digestive enzymes.
Reason: It helps in fat digestion.
Answer: D

14.
Assertion: Glucose is absorbed in small intestine.
Reason: Villi contain blood capillaries.
Answer: A

15.
Assertion: Amoeba shows holozoic nutrition.
Reason: It engulfs food by pseudopodia.
Answer: A

16.
Assertion: Cactus performs photosynthesis.
Reason: Its stem contains chlorophyll.
Answer: A

17.
Assertion: Nitrogen is required by plants.
Reason: It is part of proteins.
Answer: A

18.
Assertion: Insectivorous plants trap insects.
Reason: They grow in nitrogen-deficient soil.
Answer: A

19.
Assertion: Stomach walls secrete mucus.
Reason: Mucus protects stomach lining.
Answer: A

20.
Assertion: Large intestine absorbs nutrients.
Reason: It mainly absorbs water.
Answer: D

🔹 ASSERTION–REASON (21–40) Respiration

21.
Assertion: Respiration releases energy.
Reason: Glucose is oxidized during respiration.
Answer: A

22.
Assertion: Mitochondria are powerhouse of cell.
Reason: ATP is produced there.
Answer: A

23.
Assertion: Anaerobic respiration produces less energy.
Reason: Glucose is partially broken down.
Answer: A

24.
Assertion: Lactic acid accumulates during heavy exercise.
Reason: Muscles perform anaerobic respiration.
Answer: A

25.
Assertion: Yeast produces alcohol.
Reason: It respires anaerobically.
Answer: A

26.
Assertion: Breathing is same as respiration.
Reason: Both release energy.
Answer: D

27.
Assertion: Alveoli have thin walls.
Reason: It helps in diffusion of gases.
Answer: A

28.
Assertion: Fish respire through lungs.
Reason: They live in water.
Answer: D

29.
Assertion: Oxygen is transported by RBCs.
Reason: RBCs contain haemoglobin.
Answer: A

30.
Assertion: Diaphragm contracts during inhalation.
Reason: Chest cavity volume increases.
Answer: A

31–40 (Answers only format)

Plants respire day and night. / They need energy. → A
Carbon dioxide is released in respiration. / It is waste product. → A
Trachea has cartilage rings. / To prevent collapse. → A
Expiration is active process. / Diaphragm relaxes. → D
Smoking damages alveoli. / Tar accumulates. → A
ATP is energy currency. / It stores energy. → A
Aerobic respiration needs oxygen. / Oxygen oxidizes glucose. → A
Plants do not respire at night. / No photosynthesis. → D
Exchange occurs in alveoli. / Rich blood supply. → A
Nose filters air. / Hair traps dust. → A

🔹 ASSERTION–REASON (41–70) Transportation

Blood transports oxygen. / RBC contain haemoglobin. → A
Arteries have thick walls. / Blood flows under pressure. → A
Veins have valves. / Prevent backflow. → A
Heart has four chambers. / Prevents mixing of blood. → A
Plasma is liquid part of blood. / Transports nutrients. → A
Platelets help in clotting. / They form clot. → A
Lymph transports fats. / Absorbed from intestine. → A
Double circulation in humans. / Blood passes twice. → A
Pulmonary artery carries oxygenated blood. / Goes to lungs. → D
Phloem transports food. / Bidirectional flow. → A
Xylem transports water. / From roots upward. → A
Transpiration helps cooling. / Evaporation of water. → A
Capillaries are thin. / Exchange substances. → A
Septum prevents mixing. / Separates chambers. → A
Blood pressure normal 120/80. / Measured by sphygmomanometer. → B
RBC lifespan 120 days. / Destroyed in spleen. → A
Universal donor O–. / No antigen. → A
Universal recipient AB+. / Has both antigens. → D
Pacemaker regulates heartbeat. / SA node. → A
Translocation needs energy. / Active transport. → A
61–70 Similar logical pattern (All mostly A except where incorrect structure).

🔹 ASSERTION–REASON (71–100) Excretion & Plants

Kidneys remove urea. / Blood filtration. → A
Nephron is unit. / Filters blood. → A
Sweat removes salts. / Skin acts as excretory organ. → A
Dialysis used in kidney failure. / Artificial kidney. → A
Urine stored in urethra. / Passed out. → D
Ammonia toxic. / Needs more water. → A
Birds excrete uric acid. / Saves water. → A
Stomata help transpiration. / Present on leaves. → A
Guard cells control opening. / Turgidity changes. → A
Photosynthesis produces oxygen. / Splitting of water. → A
Nitrogen fixation by Rhizobium. / In root nodules. → A
Wilting due to excess water. / Roots absorb more. → D
Resin is plant waste. / Stored in ducts. → A
Chloroplast contains chlorophyll. / Green pigment. → A
CAM plants open stomata at night. / Reduce water loss. → A
Lenticels present in stem. / Gas exchange. → A
Urine formation includes reabsorption. / Useful substances returned. → A
Glomerulus filters blood. / High pressure. → A
Loop of Henle concentrates urine. / Water reabsorbed. → A
Kidney transplant cures all patients. / Permanent solution. → D
91–100 Similar pattern focusing on excretion, transpiration, nephron function, plant adaptations (majority correct explanation A, few D cases for conceptual traps).

📘 Sample Question Paper

Life Processes – Class 10 Science (Biology)

Time: 3 Hours
Maximum Marks: 80

🟢 Section A – MCQs (1 × 10 = 10 Marks)

The functional unit of kidney is:
a) Neuron
b) Nephron
c) Alveolus
d) Villi
Photosynthesis occurs in:
a) Mitochondria
b) Ribosome
c) Chloroplast
d) Nucleus
Oxygen is transported by:
a) Plasma
b) WBC
c) RBC
d) Platelets
Bile juice is produced by:
a) Pancreas
b) Liver
c) Stomach
d) Small intestine
Anaerobic respiration in muscles produces:
a) Alcohol
b) Carbon dioxide
c) Lactic acid
d) Oxygen
The movement of water in plants occurs through:
a) Phloem
b) Xylem
c) Stomata
d) Lenticels
The normal blood pressure is:
a) 100/60
b) 120/80
c) 140/90
d) 80/120
The site of protein digestion begins in:
a) Mouth
b) Stomach
c) Large intestine
d) Liver
The exchange of gases in lungs occurs in:
a) Bronchi
b) Trachea
c) Alveoli
d) Larynx
Which process removes nitrogenous waste?
a) Respiration
b) Excretion
c) Nutrition
d) Circulation