Answer:
Salut!
- Light enters the eye through the cornea.
- Light travels to the macula within the retina.
- Rhodopsin absorbs light, and the Vitamin A changes shape.
- Vitamin A detaches from the rhodopsin, and some vitamin A is lost.
- Vitamin A from the bloodstream replenishes what is lost. The vitamin A returns to its original shape.
Explanation:
Retina is the part of the eye that contains photosensitive cells that capture light and produce the electrical signals that the brain perceives as images. These photosensitive cells are of two kinds:
Rods contain the photosensitive pigment, rhodopsin that is needed for vision at night or in dim light. Cones function in bright light.
Rhodopsin Bleaching:
Vision in bright or excessive light requires a process called rhodopsin bleaching which is the degradation of rhodopsin upon exposure to light. Upon contact with light, rhodopsin goes through structural changes characterized by the conversion of a pigment derived from Vitamin A, 11-<em>cis</em> retinal to all <em>trans</em> retinal. This chemical conversion initiates a photo-transduction reaction (reaction in which a photon of light is converted into electrical signals) that produces the electrical signals that travel to the brain via the optic nerve. The brain converts the electrical signals to images. This is followed by rhodopsin regeneration in the dark in which all <em>trans</em> retinal is converted back into 11 <em>cis</em> retinal.
<span>Melanin helps protect the skin against effects of the sun such as skin cancers and premature aging. In African American skin, melanin provides a sun protection factor (SPF) equivalent to 13.4 compared to 3.4 in white skin and thus the former have lower incidences of skin disorders associated with exposure to the sun.</span>
Answer:
1 - D- Transport oxygen-rich blood to the body
Explanation:
2- D- Common Beetle
3- D- Protects the brain from injury
4- D- Attach Bones to muscles and bones to bones.
Answer
Their vision is better than their hearing. Hearing serves the same role in all …
Body language is key to communication. As prey animals, horses prefer to …
Their ears can rotate independently up to 180 degrees. Like all mammals, a …
Their ears tell a story. Horses’ ears are primarily for hearing
