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.
The answer is the first choice:
Negative feedback reverses a change in a variable that has moved outside of its normal range, whereas positive feedback strengthens it.
Feedback loops do not only apply to blood pressure. There are many examples from body temperature regulation to child birth to your AC unit at home.
Answer:
Glycolysis takes places in cytoplasm in a cell
Answer: 3. They were born of one fertilized ovum.
Explanation: A zygote is formed
when an egg is fertilized by a sperm. The zygote then undergoes a mitotic division into two and each half will further develop into a separate embryo. The two embryos formed will develop into identical twins.
