Free Receptors MCQs with Answers
61 Receptors MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Receptors are specialized cells or proteins that detect stimuli such as light, sound, pressure, temperature and chemicals, then initiate responses through sensory or hormonal pathways. Questions distinguish sensory receptors from effectors, compare receptor types, and examine stimulus conversion into nerve impulses, including the roles of rods, cones, chemoreceptors and mechanoreceptors.
Last updated
61 questions · page 1 of 4
- A. cones
- B. rods
- C. ganglion cells
- D. cells of the blind spot
Explanation: Rods contain the pigment rhodopsin, which is broken down by very low light intensities, and several rods share one sensory neurone so…
Correct answer: rods- A. only rods, packed very closely
- B. no photoreceptors at all
- C. densely packed cones, each with its own connection to the optic nerve
- D. the point where the optic nerve leaves the eye
Explanation: At the fovea the cones are crowded together and each has a private line to the brain, so two nearby points of light stimulate two separate…
Correct answer: densely packed cones, each with its own connection to the optic nerve- A. detects a change in the environment and converts it into a nerve impulse
- B. carries impulses from the spinal cord to a muscle
- C. produces a hormone in response to a stimulus
- D. connects two sensory neurones together
Explanation: Receptors are transducers: each responds to one kind of stimulus, such as light, sound, pressure or a chemical, and converts that energy…
Correct answer: detects a change in the environment and converts it into a nerve impulse- A. photoreceptors
- B. thermoreceptors
- C. chemoreceptors
- D. mechanoreceptors
Explanation: Thermoreceptors in the skin and hypothalamus detect heat and cold and feed the thermoregulatory centre.
Correct answer: photoreceptors- A. retina
- B. iris
- C. lens
- D. cornea
Explanation: Muscles of the iris widen or narrow the pupil, letting more light in during darkness and less in bright sun.
Correct answer: iris- A. rods
- B. bipolar cells
- C. cones
- D. ganglion cells
Explanation: Cones, concentrated in the fovea, work in bright light and distinguish colours in three types.
Correct answer: cones- A. cochlea of the inner ear
- B. eardrum
- C. auditory canal
- D. semicircular canals of the inner ear
Explanation: The three semicircular canals, set at right angles, contain fluid that moves when the head turns, stimulating hair cells that report…
Correct answer: semicircular canals of the inner ear- A. mechanoreceptors
- B. chemoreceptors
- C. photoreceptors
- D. thermoreceptors
Explanation: Taste buds and the olfactory epithelium respond to dissolved or volatile chemicals, which is the defining feature of chemoreceptors.
Correct answer: chemoreceptors- A. the optic nerve leaves the retina and no photoreceptors are present
- B. the lens focuses light most sharply
- C. the iris meets the cornea
- D. rods are most densely packed
Explanation: At the optic disc the axons of ganglion cells gather to form the optic nerve, leaving no space for rods or cones, so light falling there…
Correct answer: the optic nerve leaves the retina and no photoreceptors are present- A. motor neurons
- B. interneurons
- C. sensory neurons
- D. glial cells
Explanation: Sensory, or afferent, neurons bring information in from receptors, while motor neurons carry commands out to effectors.
Correct answer: sensory neurons- A. astrocytes
- B. microglia
- C. ependymal cells
- D. Schwann cells
Explanation: Schwann cells wrap themselves repeatedly around the axon, their membranes forming the insulating myelin.
Correct answer: Schwann cells- A. nodes of Ranvier
- B. synaptic clefts
- C. dendritic spines
- D. neurofibril nodes
Explanation: At the nodes the axon membrane is exposed and rich in ion channels, so the action potential jumps from node to node in saltatory…
Correct answer: nodes of Ranvier13. The minimum strength of stimulus needed to generate an action potential in a neuron is called the
- A. refractory value
- B. threshold
- C. resting potential
- D. summit potential
Explanation: A stimulus below threshold opens too few sodium channels to trigger the positive feedback of depolarisation, so nothing happens; at…
Correct answer: threshold- A. axon to dendrite to cell body
- B. cell body to dendrite to axon
- C. dendrite to cell body to axon
- D. axon to cell body to dendrite
Explanation: Dendrites receive signals and conduct them to the cell body, and the axon carries the impulse away to the terminals.
Correct answer: dendrite to cell body to axon- A. Acetylcholine
- B. Noradrenaline
- C. Dopamine
- D. GABA
Explanation: GABA, gamma aminobutyric acid, hyperpolarises the postsynaptic membrane and calms neural activity, and many sedatives enhance its action.
Correct answer: GABA- A. conditioned reflex
- B. unconditioned reflex
- C. voluntary action
- D. hormonal response
Explanation: Pavlov paired the neutral bell with food until the bell alone triggered salivation, building a reflex through experience in the cerebral…
Correct answer: conditioned reflex- A. spinal reflex
- B. cranial reflex
- C. conditioned reflex
- D. hormonal reflex
Explanation: The reflex arc passes through the brain stem rather than the spinal cord, so it is classed as a cranial reflex.
Correct answer: cranial reflex- A. interneuron
- B. sensory receptor
- C. effector such as a muscle or gland
- D. association area
Explanation: The effector, a muscle or gland, carries out the response, completing the receptor to effector pathway.
Correct answer: effector such as a muscle or gland- A. dorsal root ganglion
- B. white matter of the spinal cord
- C. cerebral cortex
- D. grey matter of the spinal cord
Explanation: Interneurons sit in the grey matter of the cord, where they synapse with the incoming sensory fibre and the outgoing motor neuron.
Correct answer: grey matter of the spinal cord- A. a reflex action
- B. a conditioned response
- C. a voluntary movement
- D. a hormonal effect
Explanation: The pupil reflex is automatic, rapid and involuntary, integrated in the brain stem, meeting every criterion of a reflex.
Correct answer: a reflex actionReceptors MCQs: common questions
Are these Receptors MCQs free?
Yes. All Receptors MCQs from Biology are free on TestUstad, with unlimited attempts and no account needed. Nothing on this page is a sample or a trial.
How many Receptors MCQs are on this page?
There are 61 Receptors MCQs in the Biology bank, shown 20 to a page with the correct answer and an explanation on each.
Does every Receptors MCQ have an explanation?
Yes. Each Receptors question shows the correct option and a written explanation of why it is correct, so a wrong answer teaches you something rather than just being marked wrong.
Can I take a timed Receptors test?
Yes. The practice button on this page starts a free Receptors test drawn from the Biology bank. It marks each answer instantly, gives you a score at the end, and can be retaken as many times as you like.