Sex-Linked Characteristics Characteristic determined by a gene or genes on sex chromosomes.

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#Id: 1172

#Unit 7. System Physiology – Animal

The sensory receptors for vision are photoreceptors, located on the retina.

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#Unit 7. System Physiology – Animal

There are two types of photoreceptors:

Rods 

Cones

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#Unit 7. System Physiology – Animal

Rods 

• Have low acuity or resolution

• are sensitive to low-intensity light

• receptors for night vision (scotopic vision)

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#Id: 1175

#Unit 7. System Physiology – Animal

Cones 

• Higher visual acuity

• responsible for vision in bright light (photopic vision) Participate in color vision

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#Unit 7. System Physiology – Animal

Inputs from eye to CNS: 

• Input from the rods 

• Input from the cones

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#Unit 7. System Physiology – Animal

Duplicity Theory 

The existence of these two kinds of input, each working maximally under different conditions of illumination