Natural selection! In the theory of natural selection, those with less beneficial traits won't live to reproduce, but those with beneficial traits will be able to reproduce and pass on those traits to their offspring, which significantly increases the frequency of those beneficial traits.
True, it comes from chromoplasts<span>
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DNA and RNA have completely different purposes in us. DNA stores and transfers genetic information (Eye and hair colour, skin colour, etc..). RNA codes amino acids and makes proteins. DNA is double stranded while RNA is single stranded. DNA uses adenine, thymine, cytosine, and guanine; while RNA uses adenine, cytosine, uracil, and guanine.