a. Between the stars, what would be the gating mechanism of the sodium channels if this was an olfactory receptor cell? b. Between the star and smiley, what types of channels are opening, AND what is their gating mechanism? Between the smiley and heart, gated C. channels open. gated channels close and

Colour blindness can result from the loss of specific types of cones, or it can occur in individuals having fewer cones of a given type. An individual has 50% less than the normal number of green cone photoreceptors in his or her retina. How would this affect his or her vision? a. This person has night blindness. He or she should start to eat more carrots to replenish the stock of retinal molecules in the retina. b. This person will have difficulty adapting to varying light levels. His or her cone receptors take much longer to adapt in a brightly lit area. c. This person does not have a colour blindness because no green cone photoreceptors are in the retina; only red, yellow, and blue photoreceptors exist. d. This person has a mild green colour blindness. He or she cannot see green colours very clearly and has difficulty distinguishing colours involving green hues.

Which of the following happens in taste receptor cells when the membrane is depolarized by a receptor potential? a. Voltage-gated Ca?+ channels open, triggering the release of neurotransmitter. b. Voltage gated K+ channels open, triggering the release of neurotransmitter. c. Voltage-gated Ca?+ channels open, inhibiting the release of neurotransmitter. d. Voltage gated K+ channels open, inhibiting the release of neurotransmitter. e. Cyclic nucleotide gated ion channels open, increasing the release of neurotransmitter.

What is the shape of a receptive field of a simple cell in the primary visual cortex?A. Either a bar or an edge, in a fixed positionB. Either a bar or an edge, anywhere within a large area of the retinaC. Either a bar or an edge, with a strong inhibitory field at one endD. A circle, with a surround that responds in the opposite way

Which of the following statements about sensory receptors is FALSE?

how does visual transduction occur in rods? Select one: a. By inhibition: light bleaches the rhodopsin molecules, which closes sodium channels. This hyperpolarizes the rods and increases GABA release. b. By excitation: light inhibits rhodopsin molecules, which blocks sodium ion influx. This depolarizes the rods and causes glutamate release. c. By inhibition: light bleaches rhodopsin molecules, which closes sodium channels. This hyperpolarizes the rods and reduces glutamate release. d. By excitation: light activates rhodopsin molecules, which opens sodium channels. This depolarizes the rods and causes glutamate release

In the olfactory receptor cells of mammals, what binds to specific odorant molecules?

Vision is a complex process. The human eye has many structures that contribute to vision. Which of the following statements describing the structures involved in the process of vision is NOT correct? a. Ciliary muscles change the shape of the lens to focus both near and distant objects. b. The cornea and lens bend light to focus the image on the retina. c. The iris relaxes and contracts to protect the retina from excess light. d. Lenses move forward or backward to control the amount of light striking the retina.

There are five basic tastes—sour, salty, sweet, bitter, and“umami.” Salt is detected when the concentration of salt outside of a taste bud cell is higher than that inside of it, and ionchannels allow the passive leakage of Na+into the cell. Theresulting change in membrane potential (see Concept 7.4)sends the “salty” signal to the brain. Umami is a savory tastegenerated by glutamate (glutamic acid, found in monosodiumglutamate, or MSG), which is used as a flavor enhancer in foodssuch as taco-flavored tortilla chips. The glutamate receptor is aGPCR, which, when bound, initiates a signaling pathway thatends with a cellular response, perceived by you as “taste.” If youeat a regular potato chip and then rinse your mouth, you willno longer taste salt. But if you eat a flavored tortilla chip andthen rinse, the taste persists. (Try it!) Propose a possible explanation for this difference.

Why is a retinal defect, such as retinitis pigmentosa, which causes tunnel vision, associated with night blindness? a. Tunnel vision and night blindness are unrelated conditions. b. The high density of rod photoreceptors in the fovea are unaffected in each condition. c. The highest resolution cone photoreceptors are found exclusively in the outer regions of the retina. d. The color-detecting cone photoreceptors have the greatest density in the outer regions of the retina. e. The highly-sensitive rod photoreceptors are located in the outer regions of the retina.