The correct answer is mRNA.
mRNA or messenger RNA is synthesized during the process of transcription, from DNA molecule which is used as a template. mRNA contains information about protein synthesis (translation) in the form of nucleotide triplets or codons.
In the example above: reference book is DNA molecule (template for copies), copies are mRNA, wood is amino acids (building blocks) and doghouse is protein.
not all but most of them do
In physical geography<span>, a </span>dune<span> is a </span>hill<span> of loose </span>sand<span> built by </span>wind<span> or the flow of water.</span><span> Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind. The valley or trough between dunes is called a </span>slack<span>. A "dune field" is an area covered by extensive sand dunes. Dunes occur, for example, in some </span>deserts<span> and along some coasts.</span>
