Answer:
The correct ansqwer is- Vitamin D
Explanation:
Vitamin D is the vitamin that can be synthesized by the human body itself therefore it is not an essential vitamin for human beings. Human skin is the part that helps in making this vitamin in humans.
The natural form of vitamin D is vitamin D3 which is formed by the sunlight exposure on the skin. When we expose our skin in the sunlight the UV radiation penetrated our skin and converts provitamin D3 into pre-vitamin D3 then this previtamin can be isomerized into the natural form of vitamin D Which is vitamin D3. So the right answer is vitamin D.
Answer:
B. The products of photosynthesis are the reactants of cellular respiration.
Answer:
the first wave of extinction may be related to rapid cooling at the end of the Ordovician Period, and the second phase is widely regarded as having been caused by the sea-level fall associated with the glaciation.
Soil, water and food are all nonliving reservoirs of infection
