"both have no direct relationship but a free efficient expression binds them" what are they? (brain game).

Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)

DNA and RNA are nucleic acids essential for the life of organisms. They are responsible for storing and transporting cellular information in a process known as protein synthesis.

Although DNA and RNA work hand in hand, they have large differences that help them complement each other and function efficiently. That is why it says: "Both have no direct relationship"

When talking about "a free efficient expression binds them" we refer to Gene Expression. It is the process that allows you to obtain proteins from genes, whose final stage is the protein synthesis, which binds both DNA and RNA.