Melanin provides pigmentation to the skin and it also provides UV ray protection (which is its role in the epidermis).
There aren't enough oxygen molecules in the air are higher altitudes
Answer : Low;High
You use high power for a more detailed view on what you are looking at and you use the low power for a general view.
Answer:
The cells of living things are made mainly of four elements: carbon, hydrogen, oxygen and nitrogen. They make up 96% of the atoms that are in living things, so they would be considered major chemicals. However, depending on how you define major, other elements that only make up a few percent of cells can top the list.
Explanation:
