In modern genetics, what does it mean to say that a gene is expressed?

• A. The gene has been replicated during S phase of the cell cycle.
• B. The gene’s information is used to produce a functional product (RNA and/or protein) in a cell.
• C. The gene’s DNA sequence has undergone a mutation that changes its nucleotide order.
• D. The gene is physically located on a chromosome within the nucleus.

Answer: (B)