Answer:
C) Both are waves of energy, but ultraviolet waves cannot be seen.
Explanation:
Both visible light and ultraviolet are two manifestations of the same thing: electromagnetic radiation (which is, basically, energy in one of its forms). They both travel empty space as waves, but visible light has a longer wavelength, which means that the distance between succesive peaks of the wave is larger than that of ultraviolet radiation. Visible light just happens to have a wavelength in the range our eyes are capable of seeing, but ultraviolet has a shorter wavelength than that, therefore we cannot see it.
A biological system is a complex network of biologically relevant entities. ... Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. source: google
These nucleotides have three parts: 1) a five carbon ribose sugar, 2) a phosphate molecule and 3) one of four nitrogenous bases: adenine, guanine, cytosine or uracil.
