The diagram shows two different synaptic pathways, Pathway X and Pathway Y, found in the human retina.
Which statement correctly explains the difference in visual properties between these two pathways?
Pathway X: High sensitivity because multiple rod cells undergo spatial summation to reach the threshold generator potential in one bipolar cell. Pathway Y: High visual acuity because each cone cell is connected to its own bipolar cell, so the brain receives separate impulses from adjacent points.
Pathway X: High visual acuity because multiple rod cells undergo temporal summation to reach the threshold generator potential in one bipolar cell. Pathway Y: High sensitivity because cone cells require less light intensity to break down their pigment, iodopsin, than rod cells.
Pathway X: Low sensitivity because multiple rod cells share a single bipolar cell, meaning a larger total light stimulus is required to trigger an action potential. Pathway Y: High visual acuity because multiple cone cells synapse with a single ganglion cell to allow precise localization.
Pathway X: High sensitivity because individual rod cells cannot generate an action potential without lateral inhibition from adjacent rod cells. Pathway Y: Low visual acuity because individual cone cells have a high threshold of stimulation, meaning impulses are rarely sent to the brain.