Important Questions Class 11 Biology Chapter 18 Neural Control and Coordination With Answers

Neural control is the rapid coordination of body functions through neurons and nerve impulses. The brain, spinal cord, nerves, synapses and neurotransmitters help organs work in a coordinated manner.

Fast coordination in the human body depends on electrical impulses, chemical synapses and precise brain control. Important Questions Class 11 Biology Chapter 18 help students prepare Neural Control and Coordination for CBSE 2026-27 school exams, NEET foundation practice and NCERT-based state board tests. The chapter includes neurons, CNS, PNS, afferent fibres, efferent fibres, resting potential, action potential, synapse, neurotransmitters, forebrain, midbrain, hindbrain, cerebrum, hypothalamus, cerebellum and medulla.

Key Takeaways

• Neural Coordination: The neural system gives quick point-to-point control through neurons.
• Human Neural System: CNS includes brain and spinal cord, while PNS includes all nerves associated with CNS.
• Nerve Impulse: Resting potential changes into action potential when Na⁺ enters the axon.
• Brain Control: Medulla controls respiration, cardiovascular reflexes and gastric secretions.

Important Questions Class 11 Biology Chapter 18 Structure 2026

Important Questions Class 11 Biology Chapter 18 for CBSE 2026-27

The chapter becomes easier when students track one signal from receptor to CNS and then to an organ. Most CBSE 2026 questions test exact terms, pathway differences and functions of brain regions.

1. What is coordination in Class 11 Biology?

Coordination is the process through which two or more organs interact and complement each other’s functions.

1. Muscles need more energy during exercise.
2. Respiration rate increases to supply more O₂.
3. Heartbeat increases to move blood faster.
4. Nerves, lungs, heart and kidneys return to normal after exercise.

Final answer: Coordination keeps organ functions synchronised.

2. Why do humans need neural control and coordination?

Humans need neural control and coordination to maintain homeostasis and quick organ responses.

1. The body has many specialised organs.
2. Organs must work together.
3. Neural system gives rapid control.
4. Endocrine system gives chemical control through hormones.

Final fact: Neural and endocrine systems coordinate body activities together.

3. How does neural coordination differ from endocrine coordination?

Neural coordination is quick and point-to-point, while endocrine coordination is chemical and hormone-based.

Final fact: Neural system and endocrine system integrate body functions.

Neural System Class 11 Biology Questions

The neural system detects, receives and transmits stimuli. Its organisation becomes more complex from lower invertebrates to vertebrates.

4. What is neural system Class 11 Biology?

Neural system is the body system made of specialised neurons that detect, receive and transmit stimuli.

1. Neurons are excitable cells.
2. They receive different stimuli.
3. They transmit impulses.
4. They coordinate body functions.

Final answer: The neural system coordinates body activities through neurons.

5. How is neural organisation different in Hydra, insects and vertebrates?

Hydra has a simple nerve net, insects have a brain with ganglia, and vertebrates have a developed neural system.

1. Hydra has a network of neurons.
2. Insects have a brain, ganglia and neural tissues.
3. Vertebrates have a highly developed neural system.

Final fact: Neural organisation becomes more complex across animal groups.

6. What are neurons?

Neurons are highly specialised cells that detect, receive and transmit different kinds of stimuli.

1. They form the functional units of the neural system.
2. They generate nerve impulses.
3. They transmit impulses through axons and synapses.
4. They support coordination.

Final answer: Neurons are structural and functional units of the neural system.

Human Neural System Class 11 Biology Questions

The human neural system has central and peripheral parts. CNS processes information, while PNS carries impulses to and from CNS.

7. What are the two divisions of the human neural system?

The human neural system has the central neural system and peripheral neural system.

1. CNS includes brain and spinal cord.
2. PNS includes all nerves associated with CNS.
3. CNS processes and controls information.
4. PNS connects CNS with body organs.

Final answer: Human neural system has CNS and PNS.

8. What is central neural system?

Central neural system includes the brain and spinal cord.

1. It processes information.
2. It controls body functions.
3. It receives sensory inputs.
4. It sends motor commands.

Final fact: CNS acts as the processing and control centre.

9. What is peripheral neural system?

Peripheral neural system includes all nerves of the body associated with the brain and spinal cord.

1. It carries impulses to CNS.
2. It carries regulatory impulses from CNS.
3. It has afferent fibres.
4. It has efferent fibres.

Final answer: PNS connects CNS with tissues and organs.

10. What are afferent and efferent nerve fibres?

Afferent fibres carry impulses to CNS, while efferent fibres carry impulses from CNS to organs.

Final fact: Afferent means towards CNS, and efferent means away from CNS.

11. What are somatic and autonomic neural systems?

Somatic neural system controls skeletal muscles, while autonomic neural system controls involuntary organs and smooth muscles.

1. Somatic system relays impulses from CNS to skeletal muscles.
2. Autonomic system transmits impulses to involuntary organs.
3. Autonomic system works through sympathetic and parasympathetic divisions.

Final answer: Somatic controls voluntary muscles, while autonomic controls involuntary organs.

12. What is visceral nervous system?

Visceral nervous system is the PNS part that carries impulses between CNS and viscera.

1. It includes nerves.
2. It includes fibres.
3. It includes ganglia.
4. It includes plexuses.

Final fact: Visceral nervous system connects CNS with internal organs.

CNS and PNS Class 11 Biology Questions

CNS and PNS questions often appear as comparisons. The easiest answer uses structure, location and function.

13. Differentiate between CNS and PNS.

CNS includes brain and spinal cord, while PNS includes nerves associated with CNS.

Final fact: CNS controls, and PNS connects.

14. Differentiate between somatic and autonomic neural system.

Somatic neural system controls skeletal muscles, while autonomic neural system controls involuntary organs.

Final fact: Autonomic system regulates internal organs.

15. What is sympathetic and parasympathetic neural system?

Sympathetic and parasympathetic systems are two divisions of the autonomic neural system.

1. They regulate involuntary organs.
2. They act on smooth muscles and glands.
3. They help maintain body balance.
4. They work under autonomic control.

Final answer: Both belong to the autonomic neural system.

Neuron Class 11 Biology Questions

A neuron has a cell body, dendrites and an axon. The direction of impulse depends on these parts.

16. Describe the structure of neuron Class 11 Biology.

A neuron has three main parts: cell body, dendrites and axon.

1. Cell body contains cytoplasm and organelles.
2. Nissl’s granules occur in cell body.
3. Dendrites receive impulses towards cell body.
4. Axon carries impulses away from cell body.
5. Synaptic knobs occur at axon terminals.

Final answer: Neuron has cell body, dendrites and axon.

17. What are Nissl’s granules?

Nissl’s granules are granular bodies present in the neuron cell body and dendrites.

1. They occur in cytoplasm.
2. They are present in dendrites also.
3. They help identify neuron structure.

Final fact: Nissl’s granules occur in cell body and dendrites.

18. What are dendrites?

Dendrites are short repeatedly branched fibres that transmit impulses towards the cell body.

1. They arise from the cell body.
2. They contain Nissl’s granules.
3. They receive impulses.
4. They carry impulses inward.

Final answer: Dendrites carry impulses towards the cell body.

19. What is axon?

Axon is a long fibre that transmits nerve impulses away from the cell body.

1. Its distal end is branched.
2. Each branch ends in a synaptic knob.
3. Synaptic knobs contain synaptic vesicles.
4. Synaptic vesicles contain neurotransmitters.

Final fact: Axon carries impulses to a synapse or neuromuscular junction.

20. Differentiate between dendrites and axon.

Dendrites carry impulses towards the cell body, while axon carries impulses away from the cell body.

Final fact: Impulse direction separates dendrites and axon.

Structure of Neuron Class 11 Biology Questions on Types of Neurons

Neuron types depend on the number of axons and dendrites. NCERT gives multipolar, bipolar and unipolar neurons with locations.

21. What are multipolar neurons?

Multipolar neurons have one axon and two or more dendrites.

1. They have several processes.
2. They occur in cerebral cortex.
3. They form a common neuron type in the brain.

Final answer: Multipolar neurons occur in cerebral cortex.

22. What are bipolar neurons?

Bipolar neurons have one axon and one dendrite.

1. They have two main processes.
2. They occur in retina of eye.
3. They transmit sensory information.

Final fact: Bipolar neurons occur in retina.

23. What are unipolar neurons?

Unipolar neurons have a cell body with one axon only.

1. They usually occur in the embryonic stage.
2. They have one process.
3. They represent a simple neuron form.

Final answer: Unipolar neurons usually occur during embryonic stage.

24. What are myelinated nerve fibres?

Myelinated nerve fibres are axons covered by Schwann cells that form myelin sheath.

1. Schwann cells wrap around the axon.
2. Myelin sheath covers the fibre.
3. Gaps occur between adjacent myelin sheaths.
4. These gaps are nodes of Ranvier.

Final fact: Myelinated fibres occur in spinal and cranial nerves.

25. What are non-myelinated nerve fibres?

Non-myelinated nerve fibres are axons enclosed by Schwann cells without myelin sheath formation.

1. Schwann cell surrounds the axon.
2. Myelin sheath does not form.
3. They occur in autonomic and somatic neural systems.

Final answer: Non-myelinated fibres lack myelin sheath.

26. Differentiate between myelinated and non-myelinated axons.

Myelinated axons have myelin sheath, while non-myelinated axons lack myelin sheath.

Final fact: Myelin sheath speeds impulse conduction.

Nerve Impulse Class 11 Biology Questions

A nerve impulse forms when ionic permeability changes across the axonal membrane. Na⁺ and K⁺ movement creates polarisation, depolarisation and repolarisation.

27. Why are neurons called excitable cells?

Neurons are called excitable cells because their membranes remain polarised and respond to stimuli.

1. Ion channels occur on neural membrane.
2. These channels are selectively permeable.
3. Stimulus changes membrane permeability.
4. Action potential forms after stimulation.

Final answer: Neurons generate impulses in response to stimuli.

28. What is resting potential Class 11 Biology?

Resting potential is the electrical potential difference across the resting neural membrane.

1. Axoplasm has high K⁺.
2. Axoplasm has negatively charged proteins.
3. Outside fluid has high Na⁺.
4. Outer membrane surface remains positive.
5. Inner membrane surface remains negative.

Final fact: Resting membrane is polarised.

29. How is resting potential maintained?

Resting potential is maintained by ionic gradients and the sodium-potassium pump.

1. Resting membrane is more permeable to K⁺.
2. Resting membrane is nearly impermeable to Na⁺.
3. Sodium-potassium pump moves 3 Na⁺ out.
4. It moves 2 K⁺ into the cell.
5. Inner side remains negative.

Final answer: The sodium-potassium pump maintains resting potential.

30. What is action potential Class 11 Biology?

Action potential is the electrical potential difference during depolarisation of the neural membrane.

1. Stimulus opens Na⁺ channels.
2. Na⁺ enters the axon rapidly.
3. Polarity reverses at that site.
4. Inner surface becomes positive.
5. Outer surface becomes negative.

Final fact: Action potential is a nerve impulse.

31. What is depolarisation of nerve fibre?

Depolarisation is reversal of membrane polarity due to rapid Na⁺ influx.

1. Stimulus increases Na⁺ permeability.
2. Na⁺ enters the axoplasm.
3. Inner membrane becomes positive.
4. Outer membrane becomes negative.

Final answer: Depolarisation generates action potential.

32. What is repolarisation of nerve fibre?

Repolarisation is restoration of resting potential due to K⁺ movement outside the membrane.

1. Na⁺ permeability rise is short-lived.
2. K⁺ permeability increases next.
3. K⁺ diffuses outside.
4. Resting polarity returns.

Final fact: Repolarisation makes the fibre responsive again.

33. Explain generation and conduction of nerve impulse.

A nerve impulse travels as a wave of depolarisation and repolarisation along the axon.

1. Stimulus makes site A freely permeable to Na⁺.
2. Na⁺ enters rapidly at site A.
3. Site A becomes depolarised.
4. Current flows from site A to site B inside the axon.
5. Site B undergoes depolarisation.
6. Site A repolarises due to K⁺ movement.
7. The sequence repeats along the axon.

Final answer: Nerve impulse moves along the axon through polarity changes.

34. What is the role of Na⁺ in action potential?

Na⁺ influx causes depolarisation and action potential generation.

1. Stimulus opens Na⁺ channels.
2. Na⁺ moves into the axon.
3. Inner surface becomes positive.
4. Polarity reverses at the stimulated site.

Final fact: Na⁺ entry starts action potential.

35. What is the role of K⁺ in repolarisation?

K⁺ outflow restores the resting membrane potential after depolarisation.

1. K⁺ permeability increases after Na⁺ entry.
2. K⁺ diffuses outside the membrane.
3. Inner surface becomes negative again.
4. Resting potential returns.

Final answer: K⁺ movement restores resting polarity.

Synapse Class 11 Biology Questions

A synapse transfers impulse from one neuron to another. Electrical synapses act faster, while chemical synapses use neurotransmitters.

36. What is a synapse?

Synapse is the junction between a pre-synaptic neuron and a post-synaptic neuron.

1. It may have a synaptic cleft.
2. It transfers impulses between neurons.
3. It can be electrical or chemical.

Final answer: Synapse connects two neurons for impulse transmission.

37. What are electrical synapses?

Electrical synapses transmit impulses directly through close membranes of two neurons.

1. Pre-synaptic and post-synaptic membranes are very close.
2. Electrical current flows directly between neurons.
3. Transmission is fast.
4. Electrical synapses are rare in humans.

Final fact: Electrical synapses are faster than chemical synapses.

38. What are chemical synapses?

Chemical synapses transmit impulses through neurotransmitters across a synaptic cleft.

1. Membranes are separated by a fluid-filled space.
2. The space is called synaptic cleft.
3. Neurotransmitters cross the cleft.
4. New potential forms in the post-synaptic neuron.

Final answer: Chemical synapses use neurotransmitters.

39. What are neurotransmitters?

Neurotransmitters are chemicals that transmit impulses across chemical synapses.

1. They occur inside synaptic vesicles.
2. Vesicles occur in axon terminals.
3. They bind receptors on post-synaptic membrane.
4. They open ion channels.

Final fact: Neurotransmitters can produce excitatory or inhibitory responses.

40. Explain transmission of impulse across a chemical synapse.

Chemical synaptic transmission uses neurotransmitter release, receptor binding and ion channel opening.

1. Action potential reaches axon terminal.
2. Synaptic vesicles move towards membrane.
3. Vesicles fuse with pre-synaptic membrane.
4. Neurotransmitters release into synaptic cleft.
5. Neurotransmitters bind post-synaptic receptors.
6. Ion channels open.
7. New potential forms in the post-synaptic neuron.

Final answer: Chemical synapse transmits impulse through neurotransmitters.

41. Differentiate between electrical and chemical synapse.

Electrical synapse is faster, while chemical synapse uses neurotransmitters.

Final fact: Electrical synapses transmit faster than chemical synapses.

Central Neural System Class 11 Biology Questions

The central neural system processes information and controls body activities. The brain acts as the command and control system.

42. What is the function of brain?

The brain processes information and controls voluntary, involuntary, sensory, emotional and endocrine-related activities.

1. It controls voluntary movements.
2. It controls body balance.
3. It controls lungs, heart and kidneys.
4. It controls thermoregulation.
5. It controls hunger and thirst.
6. It processes vision, hearing, speech and memory.

Final answer: Brain is the command and control system of the body.

43. How is human brain protected?

Human brain is protected by skull and three cranial meninges.

1. Skull provides hard protection.
2. Dura mater forms the outer meningeal layer.
3. Arachnoid forms the middle layer.
4. Pia mater touches brain tissue.

Final fact: Cranial meninges protect the brain inside the skull.

44. What are the three major parts of the brain?

The three major parts of brain are forebrain, midbrain and hindbrain.

1. Forebrain includes cerebrum, thalamus and hypothalamus.
2. Midbrain lies between forebrain and pons.
3. Hindbrain includes pons, cerebellum and medulla.

Final answer: Brain has forebrain, midbrain and hindbrain.

Forebrain Class 11 Biology Questions

Forebrain handles major sensory, motor, emotional and homeostatic functions. Cerebrum forms the largest part of the human brain.

45. What are the parts of forebrain?

Forebrain consists of cerebrum, thalamus and hypothalamus.

1. Cerebrum forms the major part.
2. Thalamus coordinates sensory and motor signalling.
3. Hypothalamus controls temperature, hunger and thirst.

Final answer: Forebrain has cerebrum, thalamus and hypothalamus.

46. What is cerebrum?

Cerebrum is the major part of the human brain divided into two cerebral hemispheres.

1. A deep cleft divides it longitudinally.
2. Left and right cerebral hemispheres form.
3. Corpus callosum connects both hemispheres.
4. Cerebral cortex covers the hemispheres.

Final fact: Cerebrum is the most developed part of the human brain.

47. What is corpus callosum?

Corpus callosum is a tract of nerve fibres connecting the two cerebral hemispheres.

1. It lies between left and right hemispheres.
2. It allows communication between hemispheres.
3. It connects cerebral regions.

Final answer: Corpus callosum connects both cerebral hemispheres.

48. What is cerebral cortex?

Cerebral cortex is the cell layer covering the cerebral hemispheres.

1. It forms prominent folds.
2. It appears grey due to neuron cell bodies.
3. It contains motor areas.
4. It contains sensory areas.
5. It contains association areas.

Final fact: Cerebral cortex is called grey matter.

49. What are association areas of cerebral cortex?

Association areas are cortical regions that are neither clearly sensory nor motor.

1. They support intersensory associations.
2. They support memory.
3. They support communication.
4. They support complex brain functions.

Final answer: Association areas handle complex brain functions.

50. What is white matter?

White matter is the inner part of cerebral hemispheres made of myelinated nerve fibres.

1. Fibres are covered with myelin sheath.
2. Myelin gives opaque white appearance.
3. White matter lies inside cerebral hemisphere.

Final fact: Myelinated fibre tracts form white matter.

51. What is thalamus?

Thalamus is a major coordinating centre for sensory and motor signalling.

1. Cerebrum wraps around thalamus.
2. It receives and coordinates signals.
3. It lies in the forebrain.

Final answer: Thalamus coordinates sensory and motor signals.

52. What is hypothalamus?

Hypothalamus is the forebrain region that controls body temperature, hunger, thirst and hormone secretion.

1. It lies at the base of thalamus.
2. It has centres for eating and drinking.
3. It has thermoregulation centres.
4. It has neurosecretory cells.
5. It secretes hypothalamic hormones.

Final fact: Hypothalamus controls homeostatic drives.

53. What is limbic system?

Limbic system includes inner cerebral hemisphere parts and deep structures like amygdala and hippocampus.

1. It works with hypothalamus.
2. It regulates sexual behaviour.
3. It controls emotional reactions.
4. It supports motivation.

Final answer: Limbic system regulates emotion, motivation and behaviour.

54. Differentiate between thalamus and hypothalamus.

Thalamus coordinates sensory and motor signals, while hypothalamus controls homeostasis and hormones.

Final fact: Hypothalamus controls body temperature and hunger.

Midbrain Class 11 Biology Questions

Midbrain lies between forebrain and pons. Its dorsal side has four round swellings called corpora quadrigemina.

55. Where is midbrain located?

Midbrain lies between thalamus or hypothalamus of forebrain and pons of hindbrain.

1. It connects forebrain and hindbrain regions.
2. Cerebral aqueduct passes through it.
3. Its dorsal part has corpora quadrigemina.

Final answer: Midbrain lies between forebrain and pons.

56. What is cerebral aqueduct?

Cerebral aqueduct is a canal that passes through the midbrain.

1. It runs through the midbrain.
2. It connects brain cavities.
3. It forms a landmark of midbrain structure.

Final fact: Cerebral aqueduct passes through midbrain.

57. What is corpora quadrigemina?

Corpora quadrigemina are four round swellings on the dorsal portion of the midbrain.

1. They are also called lobes.
2. They lie dorsally in midbrain.
3. They form a key midbrain feature.

Final answer: Corpora quadrigemina are four midbrain swellings.

Hindbrain Class 11 Biology Questions

Hindbrain controls balance, vital reflexes and connections among brain regions. It includes pons, cerebellum and medulla.

58. What are the parts of hindbrain?

Hindbrain comprises pons, cerebellum and medulla oblongata.

1. Pons has fibre tracts.
2. Cerebellum has a highly convoluted surface.
3. Medulla connects to spinal cord.

Final answer: Hindbrain has pons, cerebellum and medulla.

59. What is pons?

Pons consists of fibre tracts that interconnect different regions of the brain.

1. It belongs to hindbrain.
2. It lies above medulla.
3. It helps connect brain regions.

Final fact: Pons interconnects different brain regions.

60. What is cerebellum?

Cerebellum is a hindbrain part with a highly convoluted surface.

1. Its folds provide extra space.
2. Extra space supports more neurons.
3. It helps coordinate body balance and movement.

Final answer: Cerebellum supports balance and coordination.

61. What is medulla oblongata?

Medulla oblongata is the hindbrain part connected to the spinal cord.

1. It contains respiratory centres.
2. It controls cardiovascular reflexes.
3. It controls gastric secretions.

Final fact: Medulla controls vital involuntary functions.

62. What is brain stem?

Brain stem includes midbrain, pons and medulla oblongata.

1. It connects brain and spinal cord.
2. It includes three major regions.
3. It supports vital pathways.

Final answer: Brain stem forms connection between brain and spinal cord.

63. Differentiate between cerebrum and cerebellum.

Cerebrum handles higher processing, while cerebellum supports balance and coordination.

Final fact: Cerebrum is the most developed human brain region.

Class 11 Biology Neural Control and Coordination Questions With Answers for Board Practice

NCERT exercise questions often ask comparisons, short notes and mechanism-based answers. These answers need exact biological terms and clear sequence.

64. Which part of the human brain is most developed?

Cerebrum is the most developed part of the human brain.

1. It forms the major part of the brain.
2. It has two hemispheres.
3. It contains cerebral cortex.
4. It supports higher functions.

Final answer: Cerebrum is the most developed human brain part.

65. Which part of CNS acts as a master clock?

Hypothalamus acts as the master clock of the central neural system.

1. It controls circadian rhythms.
2. Circadian rhythm follows a 24-hour pattern.
3. It also controls hunger, thirst and temperature.

Final fact: Hypothalamus controls the body’s 24-hour rhythm.

66. Write a short note on neural coordination.

Neural coordination is rapid coordination through neurons and point-to-point connections.

1. Neurons detect stimuli.
2. They generate impulses.
3. They transmit impulses quickly.
4. They coordinate organ functions.

Final answer: Neural coordination gives fast body control.

67. Write a short note on synapse.

Synapse is the junction between two neurons for impulse transmission.

1. It forms between pre-synaptic and post-synaptic neurons.
2. It may be electrical or chemical.
3. Chemical synapse uses neurotransmitters.

Final fact: Synapse transfers nerve impulses between neurons.

68. Why is impulse transmission faster across electrical synapse?

Impulse transmission is faster across electrical synapse because current flows directly between neurons.

1. Neuronal membranes are very close.
2. Electrical current crosses directly.
3. Neurotransmitter release is not required.

Final answer: Electrical synapse gives faster impulse transmission.

69. Why can action potential be excitatory or inhibitory at a chemical synapse?

Action at a chemical synapse depends on the neurotransmitter and receptor response.

1. Neurotransmitters bind post-synaptic receptors.
2. Ion channels open.
3. A new potential forms.
4. The new potential may excite or inhibit the neuron.

Final fact: Chemical synapses can produce excitatory or inhibitory effects.