Q. It is present in rod cells and useful in night vision.
Solution:
Solution:
The adult human eyeball is almost spherical in structure and is made up of three layers. The outermost layer is called sclera which is made up of dense connective tissues. The bluish middle layer is called choroid, which is made up of blood vessels. The innermost layer is called retina. The retina has three layers of neural cells- ganglion cells, bipolar cells and photoreceptor cells. The retina consists of two photoreceptor cells, namely, rods and cones. These cells contain photopigments, which are light-sensitive proteins.
Rhodopsin is a light sensitive biological pigment found in the rods of the retina. It belongs to the group of opsins. It is also called as visual purple and it contains sensory proteins that convert light into electrical signals. It also contains a derivative of Vitamin A.
Rhodopsin is a visual pigment, which when activated, initiates the process that leads to vision. It is found in a wide range of organisms like bacterias, vertebrates, etc. It’s main function is twilight (scotopic) vision.
Mutations in rhodopsin gene (RHO), is associated with retinitis pigmentosa, night blindness and other hereditary eye diseases. It is linked to diseases where the eye cannot adapt to darkness. Retinitis pigmentosa starts with degenerative changes in the rods and night blindness at an early age in life and progresses to destruction of cones and loss of daylight vision.