🌟 Introduction

Life Processes is one of the most important chapters in the Class 10 CBSE Science syllabus. For students preparing for CBSE Board examinations, solving Previous Year Questions (PYQs) is the most effective way to understand the exam pattern, marking scheme, and frequently repeated themes. At Dhingra Classes Nashik, we have compiled the most important PYQs from this chapter, organized by marks weightage, to help Class 10 students score maximum marks.

This chapter covers Nutrition, Respiration, Transportation, Excretion, Photosynthesis, Human Digestive System, Human Respiratory System, Human Circulatory System, and Human Excretory System. These PYQs have been collected from CBSE Board exams across multiple years and are essential for effective board exam preparation.

📚 Why Solving PYQs Is Important for CBSE Class 10

Before diving into the questions, let us understand why Previous Year Questions are crucial for Class 10 CBSE students.

🎯 Benefits of Solving PYQs

• ✅ Understanding Exam Pattern: PYQs reveal how questions are framed

• 📝 Identifying Repeated Themes: Many questions repeat with slight variations

• 🧠 Better Answer Writing: PYQs help practice structured answers

• 🏆 Higher Scores: Familiarity with question types reduces exam stress

• 📊 Time Management: Practice helps allocate time per question correctly

• 🔬 Diagram Practice: Many PYQs require drawing and labeling diagrams

📖 1 Mark Questions (Very Short Answer Type)

These questions are typically asked as MCQs, Assertion-Reason, or one-line answers. They test factual knowledge and basic understanding.

Set A: MCQs and One-Line Answers

Set B: Assertion-Reason Questions

Question 1: Assertion (A): Arteries have thick elastic walls. Reason (R): Blood flows through arteries under high pressure.
Answer: Both A and R are true and R is the correct explanation of A.

Question 2: Assertion (A): Plants have low energy needs compared to animals. Reason (R): Plants do not need to move in search of food.
Answer: Both A and R are true and R is the correct explanation of A.

📖 2 Marks Questions (Short Answer Type I)

These questions require two points or brief explanations and are designed to test conceptual understanding.

Question 1: Why is the small intestine the longest part of the alimentary canal?

Answer:

• The small intestine is the longest part because it is the site of complete digestion and absorption of food.

• Its length provides a large surface area for the absorption of nutrients into the bloodstream.

Question 2: What is the role of the liver in digestion?

Answer:

• The liver secretes bile juice, which makes the acidic food coming from the stomach alkaline for the pancreatic enzymes to act.

• Bile also emulsifies fats, breaking them into small droplets for easier digestion.

Question 3: Why do we get cramps after running?

Answer:

• During running, muscles do not get enough oxygen, leading to anaerobic respiration.

• This produces lactic acid in the muscles, which causes cramps.

Question 4: What is the significance of transpiration in plants?

Answer:

• Transpiration helps in the absorption and upward movement of water and minerals from roots to leaves.

• It also helps in regulating the temperature of the plant.

Question 5: Name the two stages of photosynthesis and where do they occur?

Answer:

• The two stages are the light reaction and the dark reaction.

• The light reaction occurs in the thylakoid membranes of chloroplasts, while the dark reaction occurs in the stroma.

Question 6: Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms?

Answer:

• Aquatic organisms use dissolved oxygen in water, which is present in much lower concentration than in air.

• Therefore, they need to breathe faster to get enough oxygen.

Question 7: What is the role of the stomata in plants?

Answer:

• Stomata are small pores on the surface of leaves that allow exchange of gases (CO₂ and O₂).

• They also help in transpiration, the loss of water vapour.

Question 8: What is the function of the kidneys in the human body?

Answer:

• Kidneys filter the blood and remove waste products like urea and excess salts as urine.

• They also help in maintaining water balance and blood pressure.

📖 3 Marks Questions (Short Answer Type II)

These questions require detailed explanations with three distinct points and test analytical understanding.

Question 1: Explain the process of digestion in the human stomach.

Answer:

• The stomach is a J-shaped muscular organ that receives food from the oesophagus.

• Gastric glands in the stomach secrete hydrochloric acid, mucus, and the enzyme pepsin.

• HCl creates an acidic medium for pepsin to act, and pepsin breaks down proteins into simpler substances; mucus protects the stomach lining.

Question 2: How does the process of photosynthesis take place in plants?

Answer:

• Photosynthesis is the process by which green plants make food using carbon dioxide, water, and sunlight.

• Chlorophyll present in chloroplasts absorbs light energy, which splits water molecules into hydrogen and oxygen.

• Carbon dioxide is reduced to carbohydrates using hydrogen, and oxygen is released as a by-product.

Question 3: Explain the process of respiration in humans.

Answer:

• Respiration involves the exchange of gases and the breakdown of food to release energy.

• Inhalation brings oxygen into the lungs, which passes into the blood; exhalation removes carbon dioxide.

• In cells, glucose is broken down with oxygen to release energy, carbon dioxide, and water.

Question 4: Why is the rate of photosynthesis important for the survival of life on Earth?

Answer:

• Photosynthesis produces oxygen, which is essential for the survival of all aerobic organisms.

• It is the primary source of food for all living organisms, directly or indirectly.

• It helps in removing carbon dioxide from the atmosphere, maintaining the balance of gases.

Question 5: Explain the structure and function of the human heart.

Answer:

• The human heart is a four-chambered muscular organ with two atria and two ventricles.

• The right side pumps deoxygenated blood to the lungs, while the left side pumps oxygenated blood to the body.

• Valves prevent the backflow of blood, ensuring unidirectional flow.

Question 6: How does the human excretory system work?

Answer:

• The kidneys filter blood to remove waste products like urea in the form of urine.

• Nephrons are the functional units of the kidney that perform filtration, reabsorption, and secretion.

• Urine passes through the ureters to the urinary bladder, and is expelled through the urethra.

Question 7: Explain the process of nutrition in Amoeba.

Answer:

• Amoeba shows holozoic nutrition; it engulfs food particles by forming pseudopodia.

• The food is taken into a food vacuole, where digestive enzymes break it down.

• Absorbed nutrients are used for energy and growth, and undigested waste is expelled.

Question 8: Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?

Answer:

• Separation allows for efficient oxygen supply to the body, which is necessary for their high energy needs.

• It helps in maintaining a constant body temperature (warm-blooded animals).

• It ensures that oxygenated blood reaches the tissues without mixing with deoxygenated blood.

Question 9: Explain the role of the stomata in the process of photosynthesis.

Answer:

• Stomata are small pores on the surface of leaves that allow exchange of gases.

• Carbon dioxide enters the leaf through stomata, which is essential for photosynthesis.

• Oxygen produced during photosynthesis is released through the stomata.

Question 10: Explain the process of transpiration and its significance.

Answer:

• Transpiration is the loss of water vapour from the aerial parts of plants, mainly through stomata.

• It helps in the absorption and upward movement of water and minerals from roots to leaves.

• It also helps in regulating the temperature of the plant.

Question 11: Describe the structure and function of the nephron.

Answer:

• The nephron is the functional unit of the kidney, consisting of a glomerulus and a renal tubule.

• Filtration occurs in the glomerulus, where blood is filtered under pressure.

• Reabsorption occurs in the tubule, where useful substances are reabsorbed into the blood.

Question 12: Explain the process of digestion in the small intestine.

Answer:

• The small intestine is the site of complete digestion and absorption of food.

• Pancreatic juice and bile are secreted into the small intestine to digest carbohydrates, proteins, and fats.

• The inner lining of the small intestine has villi that increase the surface area for absorption.

📖 5 Marks Questions (Long Answer Type)

These questions require comprehensive answers with five distinct points and test in-depth understanding and analytical skills.

Question 1: Explain the process of photosynthesis in plants with the help of a diagram.

Answer:

• Photosynthesis is the process by which green plants make food using carbon dioxide, water, and sunlight.

• Chlorophyll present in chloroplasts absorbs light energy, which splits water molecules into hydrogen and oxygen.

• Carbon dioxide is reduced to carbohydrates using hydrogen, and oxygen is released as a by-product.

• The process occurs in two stages: the light reaction (in thylakoids) and the dark reaction (in stroma).

• The overall equation is: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ in the presence of sunlight and chlorophyll.

Question 2: Explain the human digestive system with the help of a diagram.

Answer:

• The human digestive system consists of the alimentary canal and associated glands.

• Mouth: Food is ingested and mixed with saliva containing salivary amylase, which breaks down starch.

• Stomach: Gastric glands secrete HCl, mucus, and pepsin; proteins are broken down into simpler substances.

• Small Intestine: Pancreatic juice, bile, and intestinal juice complete digestion; absorption occurs through villi.

• Large Intestine: Water and salts are absorbed; undigested waste is stored and expelled through the anus.

Question 3: Explain the process of respiration in humans with the help of a diagram.

Answer:

• Respiration involves the exchange of gases and the breakdown of food to release energy.

• Inhalation brings oxygen into the lungs, which passes into the blood; exhalation removes carbon dioxide.

• In cells, glucose is broken down with oxygen to release energy, carbon dioxide, and water.

• The process occurs in two stages: aerobic respiration (with oxygen) and anaerobic respiration (without oxygen).

• The overall equation is: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy.

Question 4: Explain the structure and function of the human heart with the help of a diagram.

Answer:

• The human heart is a four-chambered muscular organ with two atria and two ventricles.

• The right side pumps deoxygenated blood to the lungs, while the left side pumps oxygenated blood to the body.

• Valves prevent the backflow of blood, ensuring unidirectional flow.

• The pulmonary artery carries deoxygenated blood to the lungs, and the pulmonary vein carries oxygenated blood back to the heart.

• The heart works continuously, pumping blood through the double circulation system.

Question 5: Explain the human excretory system with the help of a diagram.

Answer:

• The human excretory system consists of the kidneys, ureters, urinary bladder, and urethra.

• The kidneys filter blood to remove waste products like urea in the form of urine.

• Nephrons are the functional units of the kidney that perform filtration, reabsorption, and secretion.

• Urine passes through the ureters to the urinary bladder, and is expelled through the urethra.

• The kidneys also help in maintaining water balance and blood pressure.

Question 6: Explain the process of nutrition in plants and animals.

Answer:

• Plants show autotrophic nutrition, making their own food through photosynthesis.

• Animals show heterotrophic nutrition, depending on other organisms for food.

• In holozoic nutrition, animals engulf food and digest it internally.

• In saprophytic nutrition, organisms feed on dead and decaying matter.

• In parasitic nutrition, organisms live on or inside other organisms and derive nutrition from them.

Question 7: Explain the process of transportation in plants.

Answer:

• Transportation in plants occurs through xylem and phloem.

• Xylem transports water and minerals from roots to all parts of the plant.

• Phloem transports food prepared in leaves to other parts of the plant.

• Transpiration creates a transpiration pull that helps in the upward movement of water.

• The process is essential for the distribution of nutrients and maintenance of water balance.

Question 8: Explain the process of transportation in humans.

Answer:

• Transportation in humans occurs through the circulatory system, which consists of the heart, blood vessels, and blood.

• The heart pumps blood through arteries, veins, and capillaries.

• Arteries carry oxygenated blood away from the heart, while veins carry deoxygenated blood back to the heart.

• Capillaries allow the exchange of gases, nutrients, and waste products between blood and tissues.

• The double circulation system ensures efficient oxygen supply to the body.

Question 9: Explain the process of excretion in plants.

Answer:

• Plants produce oxygen and carbon dioxide as waste products during photosynthesis and respiration.

• Excess water is removed through transpiration.

• Other waste products are stored in leaves, bark, and fruits, which are eventually shed.

• Some waste products are stored as resins and gums in older xylem tissues.

• Plants also excrete waste through roots into the soil.

Question 10: Explain the process of excretion in humans.

Answer:

• The human excretory system consists of the kidneys, ureters, urinary bladder, and urethra.

• The kidneys filter blood to remove waste products like urea in the form of urine.

• Nephrons are the functional units of the kidney that perform filtration, reabsorption, and secretion.

• Urine passes through the ureters to the urinary bladder, and is expelled through the urethra.

• The kidneys also help in maintaining water balance and blood pressure.

Question 11: Explain the process of nutrition in Amoeba with the help of a diagram.

Answer:

• Amoeba shows holozoic nutrition; it engulfs food particles by forming pseudopodia.

• The food is taken into a food vacuole, where digestive enzymes break it down.

• Absorbed nutrients are used for energy and growth, and undigested waste is expelled.

• The process involves ingestion, digestion, absorption, assimilation, and egestion.

• Amoeba feeds on microscopic organisms like bacteria and algae.

Question 12: Explain the process of respiration in plants.

Answer:

• Plants respire through stomata in leaves and lenticels in stems.

• Oxygen enters the plant and carbon dioxide is released during respiration.

• Glucose is broken down with oxygen to release energy, carbon dioxide, and water.

• Plants also respire anaerobically in some conditions, producing alcohol and carbon dioxide.

• The rate of respiration in plants is slower than in animals.

📝 How to Use These PYQs for CBSE Exam Preparation

At Dhingra Classes Nashik, we recommend the following strategies to maximize your score using these PYQs.

🎯 Study Tips

1. 📖 Read each question and try to answer before looking at the solution

2. ✏️ Practice writing answers within time limits (1 mark = 1 min, 3 marks = 5 min, 5 marks = 10 min)

3. 🗣️ Focus on repeated themes like photosynthesis, respiration, and human digestive system

4. 📝 Create flashcards for 1-mark questions

5. 🔬 Practice diagrams as many questions require labeled diagrams

6. 🔄 Revise weekly to ensure long-term retention

7. 📋 Practice Assertion-Reason questions as they are frequently asked

8. ✅ Take mock tests using these PYQs

🏫 How Dhingra Classes Nashik Helps Class 10 CBSE Students Master Science

At Dhingra Classes Nashik, we provide comprehensive coaching for Science and all other subjects for Class 10 CBSE students. Our approach includes:

• 📚 Structured Lessons: Teaching concepts with clear explanations

• 🔬 Diagram Practice: Regular diagram work for better understanding

• 📝 PYQ Analysis: Regular practice with previous year questions

• ✏️ Regular Tests: Weekly tests to ensure continuous revision

• 🎯 Doubt Clearing Sessions: Personalized attention to every student

• 📊 Progress Tracking: Regular updates to parents about student progress

• 🏆 Answer Writing Practice: Teaching how to structure answers for maximum marks

📞 Contact Dhingra Classes Nashik

• 📱 Phone: 98230 62106

• 📧 Email: dhingraclassesnsk@gmail.com

• 🌐 Website: www.dhingraclassesnashik.com

• 📍 Address: Plot No 3, XQ3G+H3M Deacon Homes, 301C, opp. Metro Zone, near Guru Govind Sing, Samarth Nagar, Dnyaneshwar Nagar, Pathardi Phata, Nashik, Maharashtra 422009

🏁 Conclusion

Mastering Life Processes PYQs is essential for Class 10 CBSE students to score high marks in Science board examinations. This comprehensive collection of 1-mark, 2-mark, 3-mark, and 5-mark questions covers all major themes including Nutrition, Respiration, Transportation, Excretion, Photosynthesis, Human Digestive System, Human Respiratory System, Human Circulatory System, and Human Excretory System.

By regularly practicing these Previous Year Questions and using them in your board exam preparation, you can improve your understanding and score better. At Dhingra Classes Nashik, we are committed to helping Class 10 CBSE students excel in Science and achieve academic success. Remember, Life Processes is not just about memorizing processes—it is about understanding how living organisms function and survive.