Q.1 Which part of the neuron receives signals from other neurons?
Axon
Dendrite
Myelin sheath
Synapse
Explanation - Dendrites are branched extensions of a neuron that receive signals from other neurons and convey them toward the cell body.
Correct answer is: Dendrite
Q.2 Which ion is primarily responsible for depolarization during an action potential?
Potassium (K+)
Calcium (Ca2+)
Sodium (Na+)
Chloride (Cl-)
Explanation - Depolarization occurs when sodium channels open and Na+ ions rush into the neuron, making the inside more positive.
Correct answer is: Sodium (Na+)
Q.3 The gap between two neurons is called:
Synapse
Axon terminal
Dendritic spine
Node of Ranvier
Explanation - The synapse is the junction between two neurons where neurotransmitters are released to transmit signals.
Correct answer is: Synapse
Q.4 Which neurotransmitter is most associated with mood regulation?
Acetylcholine
Serotonin
Dopamine
GABA
Explanation - Serotonin plays a key role in regulating mood, sleep, and appetite.
Correct answer is: Serotonin
Q.5 Which part of the brain controls voluntary muscle movements?
Cerebrum
Cerebellum
Medulla oblongata
Hypothalamus
Explanation - The cerebrum controls voluntary movements, intelligence, memory, and sensory perception.
Correct answer is: Cerebrum
Q.6 Which sensory receptor detects pressure and vibration?
Thermoreceptors
Mechanoreceptors
Photoreceptors
Nociceptors
Explanation - Mechanoreceptors are specialized for sensing mechanical stimuli such as touch, pressure, and vibration.
Correct answer is: Mechanoreceptors
Q.7 Which part of the eye controls the amount of light entering it?
Cornea
Lens
Iris
Retina
Explanation - The iris adjusts the size of the pupil to regulate the amount of light entering the eye.
Correct answer is: Iris
Q.8 Which cells in the retina are responsible for color vision?
Rods
Cones
Ganglion cells
Bipolar cells
Explanation - Cone cells detect color and are concentrated in the fovea of the retina, whereas rods detect low light.
Correct answer is: Cones
Q.9 Which part of the ear is responsible for maintaining balance?
Cochlea
Eustachian tube
Semicircular canals
Tympanic membrane
Explanation - Semicircular canals contain fluid and hair cells that detect rotational movements and help maintain balance.
Correct answer is: Semicircular canals
Q.10 The myelin sheath in neurons is produced by which cells in the CNS?
Schwann cells
Oligodendrocytes
Astrocytes
Microglia
Explanation - Oligodendrocytes produce myelin in the CNS, whereas Schwann cells produce myelin in the PNS.
Correct answer is: Oligodendrocytes
Q.11 Which part of the brain links the nervous and endocrine systems?
Cerebellum
Hypothalamus
Medulla
Pons
Explanation - The hypothalamus regulates hormonal secretions via the pituitary gland, linking the nervous and endocrine systems.
Correct answer is: Hypothalamus
Q.12 Which type of neuron carries impulses from the CNS to muscles or glands?
Sensory neurons
Motor neurons
Interneurons
Bipolar neurons
Explanation - Motor neurons transmit signals from the CNS to effectors like muscles and glands, causing a response.
Correct answer is: Motor neurons
Q.13 Which region of the brain is responsible for coordinating voluntary movements?
Medulla oblongata
Cerebellum
Cerebrum
Thalamus
Explanation - The cerebellum ensures smooth, coordinated voluntary movements and balance.
Correct answer is: Cerebellum
Q.14 Which type of receptor is responsible for detecting temperature changes?
Photoreceptors
Thermoreceptors
Mechanoreceptors
Chemoreceptors
Explanation - Thermoreceptors are sensitive to temperature changes in the environment or body.
Correct answer is: Thermoreceptors
Q.15 The blind spot in the human eye lacks:
Rods
Cones
Ganglion cells
Photoreceptors
Explanation - The optic disc or blind spot lacks photoreceptor cells, so no image is detected at this point.
Correct answer is: Photoreceptors
Q.16 Which structure transmits sound vibrations to the inner ear?
Tympanic membrane
Oval window
Cochlea
Auditory nerve
Explanation - The stapes transmits sound vibrations from the middle ear to the fluid-filled cochlea via the oval window.
Correct answer is: Oval window
Q.17 Which ion is involved in neurotransmitter release at synaptic terminals?
Sodium (Na+)
Calcium (Ca2+)
Potassium (K+)
Chloride (Cl-)
Explanation - Calcium influx into the axon terminal triggers vesicle fusion and neurotransmitter release into the synaptic cleft.
Correct answer is: Calcium (Ca2+)
Q.18 Which lobe of the brain processes visual information?
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Explanation - The occipital lobe of the cerebrum is responsible for processing visual input from the eyes.
Correct answer is: Occipital lobe
Q.19 Which hormone is secreted by the pineal gland and regulates sleep?
Melatonin
Adrenaline
Insulin
Cortisol
Explanation - The pineal gland secretes melatonin, which helps regulate circadian rhythms and sleep patterns.
Correct answer is: Melatonin
Q.20 Which part of the neuron conducts impulses away from the cell body?
Axon
Dendrite
Synapse
Nucleus
Explanation - The axon transmits electrical impulses from the cell body toward the axon terminals.
Correct answer is: Axon
Q.21 Which part of the ear converts sound waves into nerve impulses?
Cochlea
Pinna
Tympanic membrane
Eustachian tube
Explanation - The cochlea contains hair cells that convert mechanical vibrations into electrical signals sent to the brain via the auditory nerve.
Correct answer is: Cochlea
Q.22 Which cells in the CNS provide structural support and maintain the blood-brain barrier?
Astrocytes
Oligodendrocytes
Microglia
Ependymal cells
Explanation - Astrocytes support neurons, regulate the extracellular environment, and help form the blood-brain barrier.
Correct answer is: Astrocytes
Q.23 Which type of receptor responds to chemical stimuli in taste?
Photoreceptors
Chemoreceptors
Mechanoreceptors
Thermoreceptors
Explanation - Chemoreceptors in taste buds detect chemical substances in food, contributing to the sense of taste.
Correct answer is: Chemoreceptors
Q.24 Which part of the brain is called the 'relay station' for sensory information?
Hypothalamus
Thalamus
Medulla oblongata
Pons
Explanation - The thalamus receives sensory input and relays it to the appropriate regions of the cerebral cortex.
Correct answer is: Thalamus
Q.25 Which cranial nerve is responsible for vision?
Olfactory nerve
Optic nerve
Trigeminal nerve
Facial nerve
Explanation - The optic nerve (cranial nerve II) carries visual information from the retina to the brain.
Correct answer is: Optic nerve