BIO 264 12.3

Question 3 (1 point) Question 3 Unsaved (12_03_02) In the picture below, which letter is MOST near the area that you will find a photon of light striking rhodopsin? image Question 3 options: 1) A 2) B 3) C

1) A

Question 9 (1 point) Question 9 Unsaved (12_03_03) In the presence of light, rod cells are hyperpolarized causing glutamate release to decrease. This causes the release of neurotransmitters from bipolar cells to Question 9 options: 1) Increase 2) Decrease 3) Remain unchanged

1) Increase

Question 20 (1 point) Question 20 Unsaved (12_03_02) The image is representing a membrane potential for rod cells. What is the status of Phosphodiesterase at point B? image Question 20 options: 1) Phosphodiesterase is active and converts cGMP to GMP 2) Phosphodiesterase is inactive; cGMP is abundant 3) Phosphodiesterase is active and converts GMP to cGMP 4) Phosphodiesterase is inactive; GMP is abundant

1) Phosphodiesterase is active and converts cGMP to GMP

Question 16 (1 point) Question 16 Unsaved (12_03_02) Some animals have a reflective area in the choroid called the tapetum lucidum. This structure causes light that enters the eye to be reflected back instead of being absorbed by the pigmented cells of the choroid. What would be the advantage of this arrangement: Question 16 options: 1) Reflected light could stimulate more photoreceptors of rods giving an adaptive advantage to seeing better in the dark 2) Reflected light could stimulate more photoreceptors of cones giving an adaptive advantage to seeing better in the dark 3) Reflected light could result in less light coming in contact with the photoreceptors of cones resulting in better vision during the day 4) Reflected light could decrease cone activation by making more light available to the rods

1) Reflected light could stimulate more photoreceptors of rods giving an adaptive advantage to seeing better in the dark

Question 18 (1 point) Question 18 Unsaved (12_03_02) If a person had no Vitamin A(used to produce retinal), then what would happen? Question 18 options: 1) The person would not be able to incorporate retinal into the retina and they would only see dark 2) The person would not be able to make pigment in their pigment cells and light would reflect around the eye making everything blurry 3) The person would not be able to inhibit action potentials in the bi-polar cells 4) The person would have a larger blind spot than normal

1) The person would not be able to incorporate retinal into the retina and they would only see dark

Question 17 (1 point) Question 17 Unsaved (12_03_02) Rod cells are able to detect intensities of light with the help of rhodopsin. In response to light, rhodopsin is ______________ and Na+ channels close. The closure of Na+ channels decrease the release of glutamate from rod cells. This decrease of glutamate causes the ______________ of action potentials in ganglionic cells, allowing a response to light. Question 17 options: 1) activated; stimulation 2) activated; inhibition 3) inactivated; stimulation 4) inactivated; inhibition

1) activated; stimulation

Question 7 (1 point) Question 7 Unsaved (12_03_01) Cones and rods are part of which layer of the retina? Question 7 options: 1) photoreceptor cell neuron layer 2) bipolar cell neuron layer 3) plexiform layer 4) pigmented layer 5) ganglionic layer

1) photoreceptor cell neuron layer

Question 14 (1 point) Question 14 Unsaved (12_03_02) Select the answer that correctly describes the path taken by light and light-generated action potentials as they travel through the retina toward the brain Question 14 options: 1) rod cell, cone Cell, bipolar cell, ganglion cell, optic chiasma, optic nerve 2) rod cell, bipolar cell, ganglion cell, optic nerve, optic chiasma 3) cone cell, rod cell, bipolar cell, ganglion cell, optic chiasma, optic nerve 4) rod cell, bipolar cell, ganglion cell, optic chiasma, optic nerve

2) rod cell, bipolar cell, ganglion cell, optic nerve, optic chiasma

Question 5 (1 point) Question 5 Unsaved (12_03_01) This type of cell allows us to see contrasted images when there is low amounts of light. Question 5 options: 1) cones 2) rods 3) ganglion cell 4) amacrine cell

2) rods

Question 15 (1 point) Question 15 Unsaved (12_03_02) Avery Thinstark was killing hobo spiders with his ionizing radiation gun when a spider crawled on his face, causing him to accidentally shoot himself in the eyes. Avery went blind several days later as a result of a mutation to his rod cell DNA. The following information is available to help with his diagnosis: Retinal is successfully dissociating from opsin in the presence of light and phosphodiesterase is present in abundance. However, cGMP remains bound to cyclic nucleotide-gated channels. Based on this information, which of the following statements is most likely true of Avery's mutation? Question 15 options: 1) Avery's mutation likely damaged genes that produce bipolar cell glutamate receptors, causing the receptors to permanently bind glutamate 2) Avery's mutation likely damaged bipolar cell glutamate receptors, causing the receptors to never bind glutamate 3) Avery's mutation likely damaged genes that produce transducin, causing phosphodiesterase to be permanently inactive 4) Avery's mutation likely damaged genes that produce transducin, causing phosphodiesterase to be permanently active

3) Avery's mutation likely damaged genes that produce transducin, causing phosphodiesterase to be permanently inactive

Question 2 (1 point) Question 2 Unsaved (12_03_01) Which letter in the picture above is MOST near the pupil? image Question 2 options: 1) A 2) B 3) C

3) C

Question 12 (1 point) Question 12 Unsaved (12_03_02) Imagine a condition where photoreceptors of the eye could produce NO transducin(G-protein of the retinal rods and cones). What would happen to the rod cell membrane potential? Question 12 options: 1) Voltage gated Ca++ channels would remain closed permanently, regardless of the presence or absence of light 2) Voltage gated Ca++ channels would open in the presence of light and close in the absence of light 3) Voltage gated Ca++ channels would remain open permanently, regardless of the presence or absence of light 4) Voltage gated Ca++ channels would close in the presence of light and open in the absence of light

3) Voltage gated Ca++ channels would remain open permanently, regardless of the presence or absence of light

Question 8 (1 point) Question 8 Unsaved (12_03_02) Which of the following events does not occur in a rod cell as a result of light striking the retina? Question 8 options: 1) retinal undergoes a conformational change and is released from opsin 2) cGMP is converted to GMP by phosphodiesterase 3) cGMP is released from cyclic-nucleotide gated channels 4) cyclic nucleotide-gated channels open allowing Na+ and Ca++ ions to flow into the cell

3) cGMP is released from cyclic-nucleotide gated channels

Question 6 (1 point) Question 6 Unsaved (12_03_01) Vision is a result of Question 6 options: 1) the light passes through the pupil and the brain interprets the wavelength of light into a color 2) the visual cortex converts all wavelengths into color for interpretation by the cerebrum 3) the light striking the retina is converted into action potentials, relayed to the brain and interpreted into images 4) the light passes through the lens and cornea to the humors and is converted into action potentials and interpreted by the neurons in the retina

3) the light striking the retina is converted into action potentials, relayed to the brain and interpreted into images

Question 13 (1 point) Question 13 Unsaved (12_03_02) Imagine a condition where photoreceptors of the eye could produce NO transducin(G-protein of the retinal rods and cones). What would happen to the rod cell membrane potential? Question 13 options: 1) An affected individual would lose the ability to distinguish colors but would retain the ability to distinguish black and white 2) An affected individual would lose the ability to distinguish black and white but would retain the ability to distinguish colors 3) An affected individual would constantly process visual stimuli, even in the absence of light 4) An affected individual would lose their sight entirely

4) An affected individual would lose their sight entirely

Question 19 (1 point) Question 19 Unsaved (12_03_02) The image is representing a membrane potential for rod cells. What is the status of glutamate release by rod cells at point A? image Question 19 options: 1) Glutamate is released by bipolar cells, not rod cells 2) At point A, rod cells release either a greatly decreased amount of glutamate or none at all 3) At point A, rod cells release rhodopsin rather than glutamate 4) At point A, rod cells release a continual stream of glutamate

4) At point A, rod cells release a continual stream of glutamate

Question 1 (1 point) Question 1 Unsaved (12_03_03) Which of the following is TRUE about a retina in the dark? Question 1 options: 1) Most of the retinal will be trans retinal in the photoreceptors 2) Most of the phosphodiesterase enzymes will be activated in the photoreceptors 3) Most of the cation channels will NOT have a cGMP attached 4) Most of the alpha subunits of the transducin G-protein complex will be bound to the beta and gamma subunits in an inactivated form 5) All of the above are TRUE 6) None of the above are TRUE

4) Most of the alpha subunits of the transducin G-protein complex will be bound to the beta and gamma subunits in an inactivated form

Question 10 (1 point) Question 10 Unsaved (12_03_02) Iodopsin is similar to shodopsin but is found in cone cells and not rod cells. There are three types of iodopsin that respond to three different wave lengths of light in the visible spectrum. These are: Question 10 options: 1) Red, yellow, and blue 2) Red, yellow, and green 3) Red, green, and orange 4) Red, green, and blue

4) Red, green, and blue

Question 11 (1 point) Question 11 Unsaved (12_03_02) Imagine a condition where photoreceptors of the eye could produce NO transducin(G-protein of the retinal rods and cones). What would happen to the rod cell membrane potential? Question 11 options: 1) Rod cell membrane potential would remain constant at -70 mV, regardless of the presence or absence of light 2) Rod cell membrane potential would fluctuate between -40 mV and +70 mV due to spontaneous depolarization events, regardless of the presence or absence of light 3) Rod cell membrane potential would remain constant near -70 mV in the presence of light and near -40 mV in the absence of light 4) Rod cell membrane potential would remain constant at -40, mV regardless of the presence or absence of light

4) Rod cell membrane potential would remain constant at -40, mV regardless of the presence or absence of light

Question 4 (1 point) Question 4 Unsaved (12_03_01) As light travels through the neural layer of the retina, it passes through many layers of cells. What is the correct order of cell layers that light passes through before reaching the pigmented layer? Question 4 options: 1) ganglionic layer, photoreceptor layer, bipolar layer 2) photoreceptor layer, bipolar layer, ganglionic layer 3) bipolar layer, ganglionic layer, photoreceptor layer 4) ganglionic layer, bipolar layer, photoreceptor layer

4) ganglionic layer, bipolar layer, photoreceptor layer