🌟 Introduction

Control and Coordination 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 the Nervous System, Neuron, Reflex Action, Human Brain, Spinal Cord, Endocrine System, Hormones, Plant Hormones, Tropisms, and Nastic Movements. 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): Reflex actions are automatic responses. Reason (R): They are controlled by the spinal cord without involving the brain.
Answer: Both A and R are true and R is the correct explanation of A.

Question 2: Assertion (A): The cerebrum is the largest part of the human brain. Reason (R): It controls thinking, memory, and voluntary actions.
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: What is a reflex action? Give one example.

Answer:

• A reflex action is a sudden, involuntary response to a stimulus.

• Example: Withdrawing your hand immediately after touching a hot object.

Question 2: Why is the use of iodised salt advisable?

Answer:

• Iodised salt provides iodine, which is essential for the synthesis of thyroxine hormone.

• Deficiency of iodine causes goitre, hence iodised salt is recommended.

Question 3: How does chemical coordination take place in animals?

Answer:

• Chemical coordination in animals takes place through hormones secreted by endocrine glands.

• Hormones are released into the bloodstream and act on specific target organs.

Question 4: Name the two types of tropism and give one example of each.

Answer:

• Phototropism: Movement of plant parts towards or away from light, e.g., shoot bending towards light.

• Geotropism: Movement of plant parts towards or away from gravity, e.g., roots growing downwards.

Question 5: What is the function of the cerebellum?

Answer:

• The cerebellum is responsible for maintaining posture and balance of the body.

• It also helps in precision of voluntary actions, such as walking in a straight line.

Question 6: Why is the pituitary gland called the master gland?

Answer:

• The pituitary gland is called the master gland because it controls the secretion of hormones from other endocrine glands.

• It secretes growth hormone and also regulates the thyroid, adrenal, and reproductive glands.

Question 7: What are the two main parts of the nervous system?

Answer:

• The two main parts are the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

• CNS consists of the brain and spinal cord, while PNS consists of nerves throughout the body.

Question 8: What is the role of auxin in plant growth?

Answer:

• Auxin promotes cell elongation in plants, especially in stems and roots.

• It is responsible for phototropism, causing shoots to bend towards light.

📖 3 Marks Questions (Short Answer Type II)

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

Question 1: Explain the structure and function of a neuron.

Answer:

• A neuron consists of a cell body, dendrites, and axon; dendrites receive impulses, and the axon transmits them.

• The axon is covered by a myelin sheath that insulates it and speeds up impulse transmission.

• Synapse is the gap between two neurons where neurotransmitters carry impulses from one neuron to another.

Question 2: Explain the reflex arc with the help of an example.

Answer:

• A reflex arc is the pathway taken by nerve impulses during a reflex action.

• It involves receptor → sensory neuron → spinal cord → motor neuron → effector.

• Example: When you touch a hot object, the receptor in the skin sends an impulse to the spinal cord, which sends a response to the muscle to withdraw the hand.

Question 3: Explain the role of hormones in the human body.

Answer:

• Hormones are chemical messengers secreted by endocrine glands into the bloodstream.

• They act on specific target organs and regulate various body functions.

• For example, insulin regulates blood sugar, thyroxine regulates metabolism, and adrenaline prepares the body for emergencies.

Question 4: Explain the structure and function of the human brain.

Answer:

• The human brain has three main parts: cerebrum, cerebellum, and medulla oblongata.

• The cerebrum is the largest part and controls thinking, memory, and voluntary actions.

• The cerebellum maintains posture and balance, while the medulla oblongata controls involuntary actions like heartbeat and breathing.

Question 5: Explain the role of the spinal cord in the nervous system.

Answer:

• The spinal cord is part of the Central Nervous System and extends from the brain.

• It serves as the main pathway for reflex actions, allowing quick responses without involving the brain.

• It also carries impulses between the brain and the rest of the body.

Question 6: Explain the process of phototropism in plants.

Answer:

• Phototropism is the movement of plant parts in response to light.

• Auxin hormone accumulates on the shaded side of the shoot, causing cell elongation on that side.

• This makes the shoot bend towards the light source, which is called positive phototropism.

Question 7: Explain the difference between reflex action and voluntary action.

Answer:

• Reflex action is an involuntary, automatic response controlled by the spinal cord, e.g., sneezing.

• Voluntary action is a conscious action controlled by the brain, e.g., writing.

• Reflex actions are faster than voluntary actions as they involve a shorter pathway.

Question 8: Explain the role of the endocrine system in the human body.

Answer:

• The endocrine system consists of glands that secrete hormones directly into the bloodstream.

• Hormones regulate growth, metabolism, reproduction, and stress responses.

• Examples include insulin from the pancreas, thyroxine from the thyroid, and adrenaline from the adrenal glands.

Question 9: Explain the structure and function of the human eye.

Answer:

• The human eye has parts like the cornea, iris, pupil, lens, and retina.

• The cornea refracts light, the iris controls pupil size, and the lens focuses light on the retina.

• The retina contains photoreceptors (rods and cones) that convert light into nerve impulses.

Question 10: Explain the process of geotropism in plants.

Answer:

• Geotropism is the movement of plant parts in response to gravity.

• Roots grow downwards (positive geotropism) to absorb water and minerals.

• Shoots grow upwards (negative geotropism) to reach sunlight for photosynthesis.

Question 11: Explain the role of the hypothalamus in the human body.

Answer:

• The hypothalamus is a small region of the brain that links the nervous system to the endocrine system.

• It secretes releasing hormones that control the pituitary gland.

• It also regulates body temperature, hunger, thirst, and sleep.

Question 12: Explain the process of nastic movements in plants.

Answer:

• Nastic movements are non-directional responses to stimuli, unlike tropisms.

• They occur due to changes in turgor pressure in plant cells.

• Example: The closing of leaves of Mimosa pudica (touch-me-not) when touched.

📖 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 structure and function of the human nervous system.

Answer:

• The human nervous system is divided into the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

• The CNS consists of the brain and spinal cord, which process and coordinate information.

• The brain has three main parts: cerebrum (thinking and memory), cerebellum (balance and posture), and medulla oblongata (involuntary actions).

• The PNS consists of nerves that connect the CNS to the rest of the body.

• Neurons are the functional units that transmit electrical impulses throughout the nervous system.

Question 2: Explain the reflex arc with the help of a diagram.

Answer:

• A reflex arc is the pathway taken by nerve impulses during a reflex action.

• It involves receptor → sensory neuron → spinal cord → motor neuron → effector.

• The receptor detects the stimulus and generates an impulse.

• The sensory neuron carries the impulse to the spinal cord, which processes it and sends a response through the motor neuron.

• The effector (muscle or gland) responds to the stimulus, e.g., withdrawing the hand from a hot object.

Question 3: Explain the role of hormones in the human body with examples.

Answer:

• Hormones are chemical messengers secreted by endocrine glands into the bloodstream.

• They act on specific target organs and regulate various body functions.

• Insulin from the pancreas regulates blood sugar levels; its deficiency causes diabetes.

• Thyroxine from the thyroid gland regulates metabolism; its deficiency causes goitre.

• Adrenaline from the adrenal glands prepares the body for emergencies (fight-or-flight response).

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

Answer:

• The human brain has three main parts: cerebrum, cerebellum, and medulla oblongata.

• The cerebrum is the largest part and controls thinking, memory, and voluntary actions.

• The cerebellum maintains posture and balance and helps in precision of voluntary actions.

• The medulla oblongata controls involuntary actions like heartbeat, breathing, and blood pressure.

• The brain is protected by the skull and surrounded by cerebrospinal fluid for shock absorption.

Question 5: Explain the process of coordination in plants.

Answer:

• Plants coordinate their responses through chemical substances called plant hormones.

• Auxin promotes cell elongation and is responsible for phototropism.

• Gibberellin promotes stem elongation and seed germination.

• Cytokinin promotes cell division and delays aging.

• Abscisic acid inhibits growth and causes stomatal closure during drought.

Question 6: Explain the difference between nervous and hormonal control in animals.

Answer:

• Nervous control is fast and short-lived, using electrical impulses through neurons.

• Hormonal control is slower and longer-lasting, using chemical messengers through the blood.

• Nervous control acts on specific muscles or glands, while hormones act on target organs throughout the body.

• Nervous control is mediated by the brain and spinal cord, while hormonal control is mediated by endocrine glands.

• Both systems work together to maintain homeostasis in the body.

Question 7: Explain the structure and function of the human eye with the help of a diagram.

Answer:

• The human eye has parts like the cornea, iris, pupil, lens, and retina.

• The cornea refracts light, the iris controls pupil size, and the lens focuses light on the retina.

• The retina contains photoreceptors (rods and cones) that convert light into nerve impulses.

• The optic nerve carries impulses to the brain, which interprets them as images.

• The eye is protected by the sclera and nourished by the choroid.

Question 8: Explain the process of reflex action and its importance.

Answer:

• A reflex action is a sudden, involuntary response to a stimulus.

• It involves a reflex arc: receptor → sensory neuron → spinal cord → motor neuron → effector.

• Reflex actions are faster than voluntary actions as they involve a shorter pathway.

• They protect the body from harmful stimuli by producing quick responses.

• Examples include sneezing, coughing, and withdrawing the hand from a hot object.

Question 9: Explain the role of the pituitary gland in the human body.

Answer:

• The pituitary gland is called the master gland as it controls other endocrine glands.

• It secretes growth hormone, which regulates body growth.

• It secretes thyroid-stimulating hormone (TSH), which controls the thyroid gland.

• It secretes adrenocorticotropic hormone (ACTH), which controls the adrenal glands.

• It also secretes gonadotropins, which control the reproductive glands.

Question 10: Explain the process of phototropism and geotropism in plants.

Answer:

• Phototropism is the movement of plant parts in response to light.

• Auxin accumulates on the shaded side, causing cell elongation and bending towards light.

• Geotropism is the movement of plant parts in response to gravity.

• Roots grow downwards (positive geotropism) to absorb water and minerals.

• Shoots grow upwards (negative geotropism) to reach sunlight for photosynthesis.

Question 11: Explain the structure and function of the human ear.

Answer:

• The human ear has three parts: outer ear, middle ear, and inner ear.

• The outer ear (pinna and auditory canal) collects sound waves.

• The middle ear (eardrum and ossicles) amplifies sound vibrations.

• The inner ear (cochlea) converts sound vibrations into nerve impulses.

• The auditory nerve carries impulses to the brain, which interprets them as sound.

Question 12: Explain the role of the endocrine system in maintaining homeostasis.

Answer:

• The endocrine system consists of glands that secrete hormones directly into the bloodstream.

• Hormones regulate growth, metabolism, reproduction, and stress responses.

• Insulin and glucagon maintain blood sugar levels.

• Thyroxine regulates metabolism, and adrenaline prepares the body for emergencies.

• The endocrine system works with the nervous system to maintain homeostasis in the body.

📝 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 reflex action, neuron, and hormones

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 Control and Coordination 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 Nervous System, Neuron, Reflex Action, Human Brain, Spinal Cord, Endocrine System, Hormones, Plant Hormones, Tropisms, and Nastic Movements.

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, Control and Coordination is not just about memorizing processes—it is about understanding how living organisms respond to their environment.