Question

Which of the following statement is incorrect?
A.The ear ossicles attached to the tympanic membrane are malleus.
B.Opsin(of rhodopsin) develops from vitamin A.
C.The pressure on the eardrum is equalized by the Eustachian tube
D.Otolith organ consists of saccule and utricle.

Answer 1

Hint:
Rods and cones are the two types of photoreceptor cells that are present in the human eye. Rods are responsible for giving us clear vision at low light intensity while cones are accountable for vision at a higher level of light.

Complete answer:
Rhodopsin is a G-protein and is the most abundant protein found in the rod cells of the retina. Its main function as the primary photoreceptor molecule of vision. Rhodopsin contains two parts an opsin molecule and a retinal.
The opsin molecule is linked to the chromophore and comprised of 348 amino acids and has seven transmembrane domains. Once the light is absorbed by opsin it can change its form from the resting stage to a signaling stage. After that it activates the G protein, thereby resulting in a signaling cascade that produces physiological responses.
Retinal is primarily associated with vision. Retinal is also known as retinaldehyde or Vitamin A aldehyde. It is a polyene chromophore that is bound to proteins called scotopsins and photopsins and is the chemical basis of animal vision. There are two different isomers of the retina, 11-cis retinal and all-trans-retinal. These isomers are accountable for changing light photon energy into electrical impulses in the retina.
Hence the correct answer is Opsin (of rhodopsin) develops from vitamin A..

Option ‘B’ is correct

Note:
The precursor of 11-cis-retinal is the alcohol all-trans-retinol, commonly known as Vitamin A. This molecule we are acquired through the diet as mammals are unable to synthesize it. The food rich in vitamin A is vegetables like carrots, spinach, etc.