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.
<span>the way a mineral cleaves reveals its crystal structure. true.
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<span>By definition, a mineral must have a crystal structure.</span>
In ecology<span>, a </span>niche<span> (</span>CanE<span>, </span><span><span>UK:</span> <span>/<span>ˈniːʃ</span>/</span></span><span> or </span><span><span>US:</span> <span>/<span>ˈnɪtʃ</span>/</span></span>)[1] is the fit of a species living under specific environmental conditions.
<span>https://en.wikipedia.org/wiki/Ecological_niche</span>
C Fossils allow scientists to have an idea of the time scale that traits evolved.
