Sensory Receptors Practice Questions

Where are odorants detected in the nose?

o A) Nasal septum

o B) Main olfactory epithelium

o C) Nasal conchae

o D) Nasal vestibule

B) Main olfactory epithelium

What happens when an odorant binds to an olfactory receptor?

o A) It activates a G protein-coupled receptor signaling pathway

o B) It directly opens ion channels

o C) It inhibits adenyl cyclase

o D) It decreases cAMP levels

A) It activates a G protein-coupled receptor signaling pathway

Which type of photoreceptor cells are responsible for bright light and color

vision?

o A) Rods

o B) Cones

o C) Bipolar cells

o D) Ganglion cells

B) Cones

What is the role of rhodopsin in rod cells?

o A) It absorbs light and initiates a signaling pathway

o B) It releases neurotransmitters

o C) It directly opens ion channels

o D) It inhibits cGMP phosphodiesterase

A) It absorbs light and initiates a signaling pathway

What happens to cGMP levels in rod cells in the dark?

o A) They increase

o B) They decrease

o C) They remain unchanged

o D) They fluctuate

A) They increase

Which protein binds to phosphorylated rhodopsin to prevent further activation?

A) Transducin

B) Arrestin

C) Adenyl cyclase

D) Guanylate cyclase

B) Arrestin

What is the main function of cones in the visual system?

o A) Function in dim light

o B) Perceive color

o C) Detect motion

o D) Respond to a single photon

B) Perceive color

Which enzyme synthesizes cGMP from GTP?

o A) Adenyl cyclase

o B) Guanylate cyclase

o C) Phosphodiesterase

o D) Rhodopsin kinase

B) Guanylate cyclase

What is the effect of hyperpolarization in rod cells?

o A) It inhibits bipolar cells

o B) It depolarizes bipolar cells

o C) It increases glutamate release

o D) It closes cGMP-gated ion channels

B) It depolarizes bipolar cells

What happens to rhodopsin in the presence of light?

o A) It becomes phosphorylated

o B) It releases glutamate

o C) It activates cGMP phosphodiesterase

o D) It increases cGMP levels

C) It activates cGMP phosphodiesterase

What is the role of cAMP in olfactory signaling?

o A) It inhibits adenyl cyclase

o B) It activates cAMP-gated ion channels

o C) It decreases intracellular Ca2+ levels

o D) It closes Na+ channels

B) It activates cAMP-gated ion channels

What type of protein receptors are involved in detecting odorants?

o A) Ion channels

o B) G protein-coupled receptors

o C) Tyrosine kinase receptors

o D) Ligand-gated ion channels

B) G protein-coupled receptors

What ions influx to depolarize the neuronal membrane in olfactory signaling?

o A) K+ and Cl-

o B) Na+ and Ca2+

o C) H+ and OH-

o D) Mg2+ and SO4^2-

B) Na+ and Ca2+

What allows a small array of receptors to distinguish a vast number of

odorants?

o A) Each receptor binds to a single odorant

o B) Each odorant activates a unique combination of receptors

o C) Each receptor binds to multiple odorants

o D) Each odorant activates all receptors equally

B) Each odorant activates a unique combination of receptors

What creates a spatial map of odorant-responsive neuronal activity within the

olfactory bulb?

o A) The random distribution of neurons

o B) The specific sites in the brain linked to neurons expressing specific ORs

o C) The uniform distribution of odorant receptors

o D) The random activation of neurons

B) The specific sites in the brain linked to neurons expressing specific ORs