Answer:
True. You can get vitamin A as "preformed vitamin A" which is already active and/or you can get vitamin A as carotenoids which the body can turn into active vitamin A.
Explanation:
There are two different types of vitamin A that can be obtained from food:
1. Preformed vitamin A, which is already active, is found in animal products such as beef, fish, poultry and dairy products.
2. Provitamin A, which is the inactive form, is found in plant-based foods, such as fruits and vegetables. The most common type of provitamin A is β-carotene, which is a carotenoid that the body can turn into active vitamin A via an enzyme named β-carotene 15,15'-monooxygenase.
Answer: The correct answer would be option a.
Explanation:
The hemoglobin in red blood cell has a tendency to bind to oxygen as well carbon dioxide in a reversible manner. It depends upon the partial pressure of the gas.
For example, at tissue site, the concentration of carbon dioxide is higher than oxygen due to which the affinity of hemoglobin increases for carbon dioxide.
In hemoglobin, carbon dioxide reacts with water to form bicarbonate ions and hydrogen ions.
At alveolar site, these ions again convert into carbon dioxide and excrete out of the blood as a part of exhale air.
Photosphere,chromosphere and the corona
