<u>Answer:</u> DNA and RNA
<u>Explanation:
</u>
1. When the riddle says "both have<em> no direct relationship</em>", it refers to that although DNA and RNA work hand in hand, <u>they have large differences that help them complement and function</u>.
2. When we talk about "a free efficient <em>expression binds them</em>" we refer to gene expression. It is the process that allows you to obtain proteins from genes, <u>whose final stage</u> is the synthesis of proteins, <u>which binds both</u> DNA and RNA.
It is a reference to a person, place, event, or thing.
A common noun are words like house. Year
