What is the difference between nervous system control and hormonal control?

The nervous system and endocrine (hormonal) system are two different mechanisms the body uses for control and coordination. The nervous system uses electrical impulses to transmit information rapidly through nerve cells (neurons) to specific organs or muscles. Responses are very fast but short-lived, like pulling your hand away from heat. The hormonal system uses chemical messengers called hormones, secreted by endocrine glands directly into the bloodstream. Hormonal responses are slower but longer lasting, such as the effect of adrenaline during stress. The nervous system is suited for immediate responses while hormones control processes like growth, metabolism, and reproduction that require sustained regulation. Together, they maintain the body's internal environment and coordinate responses to external stimuli effectively.

How does a reflex action work? Explain with an example.

A reflex action is an automatic, rapid, involuntary response to a stimulus that does not involve conscious thinking. It is controlled by the spinal cord rather than the brain, which makes it extremely fast. The pathway of a reflex action is called a reflex arc. When you accidentally touch a hot object, sensory receptors in the skin detect the stimulus and send an impulse through sensory (afferent) neurons to the spinal cord. The spinal cord processes the signal and immediately sends a response through motor (efferent) neurons to the muscle, causing your hand to withdraw. Simultaneously, a signal is also sent to the brain for awareness. The brain becomes conscious of the event only after the reflex action has already occurred. Other examples include blinking, sneezing, and knee-jerk response when the knee is tapped.

What are the main hormones of the human body and their functions?

The human body produces several important hormones through various endocrine glands. The pituitary gland, called the master gland, secretes growth hormone and controls other glands. The thyroid gland produces thyroxine which regulates metabolism; its deficiency causes goitre. The adrenal gland secretes adrenaline during emergency or fear situations, increasing heart rate and blood pressure for a fight-or-flight response. The pancreas produces insulin (lowers blood glucose) and glucagon (raises blood glucose); lack of insulin causes diabetes mellitus. The testes produce testosterone, which regulates male secondary sexual characteristics, while ovaries produce oestrogen and progesterone for female sexual development and reproductive cycle. The hypothalamus links the nervous and endocrine systems by controlling the pituitary gland.

How do plants respond to stimuli through tropic movements?

Plants cannot move from place to place, but they respond to environmental stimuli through directional growth movements called tropic movements (tropisms). These are controlled by a plant hormone called auxin. Phototropism is the growth of a plant toward light. Auxin accumulates on the shaded side of a stem, causing those cells to elongate more, bending the plant toward light. This is why plants on windowsills grow toward sunlight. Geotropism is the response to gravity — roots grow downward (positive geotropism) and shoots grow upward (negative geotropism). Hydrotropism is growth toward water — roots grow toward moisture. Thigmotropism is the response to touch, seen in climbing plants like pea tendrils that coil around a support. These movements help plants optimise their access to light, water, and physical support.

What is the role of the brain in controlling body functions?

The human brain is the main control centre of the nervous system and is divided into three main regions: the forebrain, midbrain, and hindbrain. The forebrain includes the cerebrum, which is responsible for thinking, memory, voluntary actions, reasoning, and interpreting sensory information. It is the largest and most complex part. The thalamus relays sensory information to the cerebrum, and the hypothalamus regulates body temperature, hunger, thirst, and controls the pituitary gland. The midbrain controls visual and auditory reflexes. The hindbrain includes the cerebellum, which coordinates movement and balance, the pons, which helps control breathing, and the medulla oblongata, which regulates involuntary actions like heartbeat, breathing, and blood pressure. The brain is protected by the skull and three layers of membranes called meninges.

NCERT Solutions for Class 10 Science Chapter 6 Control and Coordination

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NCERT Solutions for Class 10 Science Chapter 6: Control and Coordination

Understanding how living organisms respond to changes around them is at the heart of Chapter 6 — Control and Coordination. This chapter explains the remarkable systems that allow both plants and animals to detect stimuli and respond appropriately. For Class 10 students appearing in CBSE board exams, having clear and accurate NCERT solutions is essential. Myclass24 provides stepwise, exam-ready NCERT Solutions for Class 10 Science Chapter 6 that are crafted to help students score better while building genuine conceptual clarity.

From reflex arcs to the role of hormones, every topic is explained in simple language with proper diagrams wherever needed. Whether you are preparing for your school test or the board exam, these solutions give you everything you need to understand the nervous system, endocrine system, and plant movements in one place.

Download NCERT Solutions for Class 10 Science Chapter 6 PDF

Students can easily download the NCERT Solutions for Class 10 Science Chapter 6 — Control and Coordination PDF from Myclass24. The PDF is well-structured, mobile-friendly, and covers all in-text and exercise questions from the NCERT textbook. It is regularly reviewed to match the latest CBSE syllabus. Whether you study on your phone, tablet, or laptop, the PDF loads quickly and is easy to navigate. Save it offline for last-minute revision before exams.

Chapter 6: Control and Coordination — Key Concepts, Facts & Topic Breakdown

Chapter 6 is divided into two major sections: the nervous system in animals and control/coordination in plants. The human nervous system consists of the central nervous system (brain and spinal cord) and the peripheral nervous system. Neurons are the basic structural and functional units of the nervous system. A reflex action is an involuntary and spontaneous response to a stimulus, such as pulling your hand away from a hot object.

The brain has three main parts: the forebrain (controls thinking, memory, and voluntary actions), the midbrain, and the hindbrain (controls involuntary functions like breathing). The endocrine system complements the nervous system by releasing chemical messengers called hormones directly into the bloodstream.

Important Hormones and Their Functions

Hormone	Gland	Function
Adrenaline	Adrenal Gland	Prepares body for emergency — increases heart rate, blood flow
Insulin	Pancreas	Lowers blood glucose level
Thyroxine	Thyroid Gland	Regulates metabolism, growth
Growth Hormone	Pituitary Gland	Controls body growth and development
Testosterone	Testes	Male secondary sexual characteristics
Oestrogen	Ovaries	Female secondary sexual characteristics

Types of Plant Movements (Tropism)

Movement Type	Stimulus	Example
Phototropism	Light	Shoot bends towards light (positive phototropism)
Geotropism	Gravity	Roots grow downward (positive geotropism)
Hydrotropism	Water	Roots grow towards water
Chemotropism	Chemical	Pollen tube grows towards ovule
Thigmotropism	Touch	Tendril of pea plant coils around support

Quick Facts for Exam Revision

Reflex arc path: Receptor → Sensory neuron → Spinal cord → Motor neuron → Effector
Synapse is the gap between two neurons where nerve signals pass via neurotransmitters
Iodine deficiency causes goitre — an enlargement of the thyroid gland
Auxin is a plant hormone that causes cell elongation on the shaded side, making the shoot bend towards light
Abscisic acid is known as the 'stress hormone' in plants — it promotes leaf fall and seed dormancy
The pituitary gland is called the 'master gland' because it controls other endocrine glands
Insulin was the first hormone to be produced artificially using recombinant DNA technology

Exercise Questions Summary — Chapter 6

Question No.	Topic Covered	Type
Q1	What is the role of the brain in reflex action?	Short Answer
Q2	Distinguish between tropic and nastic movements	Differentiation
Q3	Nervous and hormonal mechanisms in coordination	Conceptual
Q4	Role of iodine in the body	Fact-based
Q5	Reflex arc diagram and explanation	Diagram-based