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:
Guard cells prevents this from happening
Answer:
The living organisms must not reach equilibrium in the concentration of oxygen and carbon dioxide so that the Exchange of gases continues . Otherwise respiration and photosynthesis will stop.
Explanation:
- Gases move along the concentration gradient i.e. from their higher concentration to lower concetration.
- If living organisms reach a equilibrium of carbon dioxide and oxygen concentration, then The gases will not move in and out of the cells.
- This is because at state of equilibrium the concentration of gases on both side become equal and the movement completely ceases.
- If gaseous exchange in the body stops the process of respiration and photosynthesis in Plants and respiration in animal will completely stop.
The correct answer is (b)The vestibular sense may be capable of sensory adaptation
Astronauts experience similar feelings of dizziness and disorientation upon arrival in space and upon their arrival back on Earth because the vestibular sense may be capable of changing adaptation. The dizziness and disorientation is due to the floating fluid in inner ear around zero gravity and it goes right away after some time when the astronauts reach the space. The adaptation is done by the brain to ignore the signals of the ear; the feeling this sensation for sometime the brain becomes adaptable and does not listens to the inner ear every time. This is a kind of sensory adaptation.
I think it's A.Protoplasm is mainly composed of nucleic acids,proteins,lipids,water and carbohydrates.If I'm wrong then i'm sorry.
