Biology
Garima feels difficulty in seeing in dim light and during nights. Which of the following could not be the cause of her condition ?
- Deficiency of vitamin A.
- Non-formation of the pigment visual purple.
- Excessive synthesis of pigment iodopsin.
- Rods do not synthesize the pigment rhodopsin.
Sense Organs
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Answer
Excessive synthesis of pigment iodopsin
Reason — Night vision depends on rod cells and their pigment rhodopsin (visual purple). Iodopsin is present in cone cells and is concerned with bright-light and colour vision. Therefore, excessive synthesis of iodopsin cannot cause difficulty in seeing in dim light or at night.
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