The answer is C. It is naturally occurring
Because humans and all other organisms use some combination of these elements. if we lost a whole species everything would be out of balance and we would slowly lose everything and in the in, causing a global scale extinction event. <span />
<span>The importance of fluorescent markers lays in the fact that they mark different colors for different nucleotide bases and determine which is which. This distinguishes the nucleotides to assist in sequencing DNA.</span>
