SUMMARY: The chapter "Control and Coordination" in Class 10 Science explores how living organisms control and coordinate their actions and responses to stimuli through the nervous and endocrine systems. KEY TOPICS: Nervous system, neurons, reflex action, human brain, coordination in plants, hormones in animals, endocrine glands, feedback mechanisms, plant hormones, tropic movements.
What is the basic functional unit of the nervous system?
ANeuron
BGlial cell
CSynapse
DAxon
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Correct answer: Option 1 — Neuron
Q21 Mark
Which part of the brain is responsible for coordination and balance?
ACerebrum
BCerebellum
CBrainstem
DThalamus
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Correct answer: Option 2 — Cerebellum
Q31 Mark
What is the role of the endocrine system in the body?
ATo transmit electrical signals
BTo produce hormones
CTo control reflex actions
DTo regulate temperature
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Correct answer: Option 2 — To produce hormones
Q41 Mark
Which hormone is primarily responsible for regulating blood sugar levels?
AInsulin
BAdrenaline
CThyroxine
DCortisol
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Correct answer: Option 1 — Insulin
Q51 Mark
What is a reflex action?
AA voluntary response to stimuli
BAn involuntary response to stimuli
CA learned behavior
DA complex thought process
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Correct answer: Option 2 — An involuntary response to stimuli
Q61 Mark
Which plant hormone is responsible for cell elongation?
AAuxin
BGibberellin
CCytokinin
DEthylene
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Correct answer: Option 1 — Auxin
Q71 Mark
What type of movement do plants exhibit in response to light?
AThigmotropism
BPhototropism
CHydrotropism
DGeotropism
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Correct answer: Option 2 — Phototropism
Q81 Mark
Which part of the neuron receives signals from other neurons?
AAxon
BDendrite
CCell body
DSynapse
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Correct answer: Option 2 — Dendrite
Q91 Mark
What is the function of the hypothalamus in the human brain?
ARegulates emotions
BControls body temperature
CCoordinates muscle movements
DProcesses visual information
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Correct answer: Option 2 — Controls body temperature
Q101 Mark
Which of the following is NOT an endocrine gland?
AThyroid
BPancreas
CAdrenal
DKidney
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Correct answer: Option 4 — Kidney
Q111 Mark
What is the feedback mechanism that regulates hormone levels in the body?
APositive feedback
BNegative feedback
CNeutral feedback
DCyclic feedback
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Correct answer: Option 2 — Negative feedback
Q121 Mark
Which of the following is a function of adrenaline?
AStimulates digestion
BIncreases heart rate
CPromotes sleep
DReduces stress
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Correct answer: Option 2 — Increases heart rate
Q131 Mark
What type of neurons carry signals from the brain to muscles?
ASensory neurons
BMotor neurons
CInterneurons
DAfferent neurons
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Correct answer: Option 2 — Motor neurons
Q141 Mark
Which plant hormone is involved in the ripening of fruits?
AAuxin
BGibberellin
CEthylene
DCytokinin
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Correct answer: Option 3 — Ethylene
Q151 Mark
What is the primary role of the spinal cord in the nervous system?
ATo process sensory information
BTo connect the brain to the peripheral nervous system
CTo control voluntary movements
DTo regulate hormonal activities
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Correct answer: Option 2 — To connect the brain to the peripheral nervous system
Short Answer Questions10 questions
Q163 Marks
What is the basic functional unit of the nervous system?
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The basic functional unit of the nervous system is the neuron. Neurons are specialized cells that transmit nerve impulses and facilitate communication within the nervous system.
Q173 Marks
Explain the role of reflex actions in the human body.
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Reflex actions are automatic responses to stimuli that occur without conscious thought. They help protect the body from harm by enabling quick reactions, such as pulling away from a hot surface.
Q183 Marks
What are the main parts of the human brain and their functions?
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The main parts of the human brain include the cerebrum (responsible for higher brain functions like thought and action), cerebellum (coordinates movement and balance), and brainstem (controls basic life functions such as breathing and heart rate).
Q193 Marks
Describe the process of tropic movements in plants.
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Tropic movements in plants are directional growth responses to environmental stimuli. For example, phototropism is the growth of a plant towards light, while gravitropism is the growth response to gravity.
Q203 Marks
What is the function of hormones in the human body?
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Hormones are chemical messengers produced by endocrine glands that regulate various physiological processes, including growth, metabolism, and reproduction, by signaling target organs and tissues.
Q213 Marks
Differentiate between the central nervous system and the peripheral nervous system.
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The central nervous system (CNS) consists of the brain and spinal cord, which process information and coordinate responses. The peripheral nervous system (PNS) includes all the nerves outside the CNS, connecting the CNS to the rest of the body.
Q223 Marks
What is the role of feedback mechanisms in the endocrine system?
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Feedback mechanisms in the endocrine system help maintain homeostasis by regulating hormone levels. For example, negative feedback inhibits hormone production when levels are sufficient, while positive feedback enhances hormone production during specific processes like childbirth.
Q233 Marks
Explain the structure and function of a neuron.
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A neuron consists of three main parts: the cell body (contains the nucleus), dendrites (receive signals from other neurons), and the axon (transmits impulses away from the cell body). This structure allows for efficient communication within the nervous system.
Q243 Marks
What are the different types of plant hormones and their functions?
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The main types of plant hormones include auxins (promote cell elongation and growth), gibberellins (stimulate seed germination and flowering), cytokinins (promote cell division), and abscisic acid (inhibits growth and promotes dormancy).
Q253 Marks
How does the human body respond to a stimulus through reflex action?
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When a stimulus is detected, sensory neurons transmit the information to the spinal cord, where interneurons process the signal and send a response through motor neurons to effectors, such as muscles, resulting in a quick reaction without involving the brain.
Long Answer Questions6 questions
Q266 Marks
Explain the structure and function of neurons in the nervous system. How do they facilitate communication within the body?
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Neurons are specialized cells that transmit nerve impulses throughout the body. They consist of three main parts: the cell body, dendrites, and axon. The cell body contains the nucleus and organelles, while dendrites receive signals from other neurons. The axon transmits impulses away from the cell body to other neurons or muscles. Neurons communicate through synapses, where neurotransmitters are released, allowing signals to pass from one neuron to another. This intricate network enables rapid responses to stimuli, essential for coordination and control in living organisms.
Q276 Marks
Describe the process of reflex action and its significance in the human body. Include the roles of sensory and motor neurons in your explanation.
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Reflex action is an involuntary and rapid response to a stimulus, designed to protect the body from harm. The process begins when a sensory neuron detects a stimulus and sends an impulse to the spinal cord. Here, the impulse is relayed to a motor neuron, which then triggers a response in the effector (muscle or gland). This bypasses the brain for a quicker reaction, illustrating the efficiency of the nervous system. Reflex actions, such as pulling away from a hot surface, are crucial for survival as they minimize potential injury by enabling immediate responses to harmful stimuli.
Q286 Marks
Discuss the role of the human brain in coordination and control of body functions. How does it integrate information from different sensory modalities?
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The human brain is the central organ of the nervous system, responsible for coordinating and controlling various body functions. It processes and integrates information received from different sensory modalities, such as sight, sound, and touch, through specialized areas. For instance, the occipital lobe processes visual information, while the temporal lobe handles auditory signals. The brain then interprets this information and coordinates appropriate responses, ensuring that the body reacts effectively to environmental changes. This integration is vital for complex behaviors and decision-making processes, highlighting the brain's role in maintaining homeostasis and responding to stimuli.
Q296 Marks
Explain the concept of tropic movements in plants. How do these movements differ from nastic movements?
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Tropic movements in plants are directional growth responses to environmental stimuli, such as light (phototropism) or gravity (gravitropism). These movements occur due to differential growth rates on different sides of the plant, allowing it to grow towards or away from the stimulus. In contrast, nastic movements are non-directional responses that occur independently of the direction of the stimulus, such as the closing of a flower at night. Tropic movements are crucial for optimizing light absorption and anchoring roots, while nastic movements often serve protective functions for the plant.
Q306 Marks
What are hormones, and how do they function in the endocrine system? Discuss the role of feedback mechanisms in hormone regulation.
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Hormones are chemical messengers produced by endocrine glands that regulate various physiological processes in the body, including growth, metabolism, and reproduction. They are secreted directly into the bloodstream and travel to target organs to elicit specific responses. Feedback mechanisms, particularly negative feedback, play a crucial role in maintaining hormonal balance. For example, when hormone levels rise, they can inhibit further secretion from the gland, ensuring that the body maintains homeostasis. This regulatory system is essential for the proper functioning of the endocrine system and overall health.
Q316 Marks
Describe the different types of plant hormones and their roles in growth and development. How do they influence tropic movements?
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Plant hormones, or phytohormones, include auxins, gibberellins, cytokinins, abscisic acid, and ethylene, each playing distinct roles in growth and development. Auxins promote cell elongation and are crucial for phototropism, directing plants to grow towards light. Gibberellins stimulate stem elongation and seed germination, while cytokinins promote cell division and shoot growth. Abscisic acid is involved in stress responses, and ethylene regulates fruit ripening. These hormones influence tropic movements by altering growth patterns in response to environmental stimuli, ensuring that plants adapt effectively to their surroundings.
Assertion–Reason Questions8 questions
Q321 Mark
Assertion (A): The nervous system is responsible for coordinating voluntary and involuntary actions in the body.
Reason (R): The nervous system consists of neurons that transmit signals throughout the body.
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Correct answer: Option 1 —
Both A and R are true, and R is the correct explanation of A.
Q331 Mark
Assertion (A): Reflex actions occur without the involvement of the brain.
Reason (R): Reflex actions are processed in the spinal cord, allowing for quick responses to stimuli.
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Correct answer: Option 1 —
Both A and R are true, and R is the correct explanation of A.
Q341 Mark
Assertion (A): The human brain is divided into the cerebrum, cerebellum, and medulla.
Reason (R): The cerebrum is responsible for higher brain functions, while the cerebellum coordinates movement and the medulla controls involuntary functions.
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Correct answer: Option 1 —
Both A and R are true, and R is the correct explanation of A.
Q351 Mark
Assertion (A): Plant hormones are responsible for the growth and movement of plants towards light.
Reason (R): Tropic movements in plants are influenced by hormones such as auxins that promote growth in specific directions.
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Correct answer: Option 1 —
Both A and R are true, and R is the correct explanation of A.
Q361 Mark
Assertion (A): All hormones in the endocrine system are produced by the same gland.
Reason (R): Different hormones are produced by various endocrine glands such as the pituitary, thyroid, and adrenal glands.
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Correct answer: Option 3 —
A is true, but R is false.
Q371 Mark
Assertion (A): Feedback mechanisms in the endocrine system help maintain homeostasis.
Reason (R): Feedback mechanisms regulate hormone levels to ensure the body remains in a stable state.
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Correct answer: Option 1 —
Both A and R are true, and R is the correct explanation of A.
Q381 Mark
Assertion (A): Neurons are the basic structural and functional units of the nervous system.
Reason (R): Neurons transmit electrical impulses and are essential for communication within the nervous system.
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Correct answer: Option 1 —
Both A and R are true, and R is the correct explanation of A.
Q391 Mark
Assertion (A): Tropic movements in plants are only influenced by gravity.
Reason (R): Tropic movements can be influenced by light, gravity, and water, not just gravity alone.
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Correct answer: Option 4 —
A is false, but R is true.
Statement-Based Questions8 questions
Q401 Mark
Statement 1: The nervous system is responsible for controlling voluntary actions in the body.
Statement 2: Neurons are the basic structural and functional units of the nervous system.
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Correct answer: Option 1 —
Both statements are true.
Q411 Mark
Statement 1: Reflex actions are controlled by the brain.
Statement 2: The spinal cord plays a crucial role in reflex actions.
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Correct answer: Option 3 —
Only Statement 2 is true.
Q421 Mark
Statement 1: The human brain is divided into the cerebrum, cerebellum, and medulla.
Statement 2: The cerebellum is primarily responsible for regulating hormones in the body.
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Correct answer: Option 4 —
Both statements are false.
Q431 Mark
Statement 1: Plant hormones are responsible for growth and response to stimuli.
Statement 2: Tropic movements in plants are independent of environmental stimuli.
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Correct answer: Option 2 —
Only Statement 1 is true.
Q441 Mark
Statement 1: Endocrine glands secrete hormones directly into the bloodstream.
Statement 2: Hormones have no effect on the functioning of target organs.
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Correct answer: Option 4 —
Both statements are false.
Q451 Mark
Statement 1: Feedback mechanisms are essential for maintaining homeostasis in the body.
Statement 2: All hormones are produced by the same endocrine gland.
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Correct answer: Option 2 —
Only Statement 1 is true.
Q461 Mark
Statement 1: Neurons transmit signals through electrical impulses.
Statement 2: Reflex actions occur after a delay due to processing in the brain.
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Correct answer: Option 3 —
Only Statement 2 is true.
Q471 Mark
Statement 1: Coordination in plants occurs through the action of plant hormones.
Statement 2: The nervous system is not involved in the coordination of voluntary movements.
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Correct answer: Option 4 —
Both statements are false.
