Final answer:
The DNA sequence of a gene is copied into mRNA, which is then translated into a protein during gene expression. The processes are known as transcription and translation, respectively.
Step-by-step explanation:
When a gene is expressed, its DNA sequence is copied into mRNA (RNA), and sometimes translated into protein. The correct answer to the student's question is 'E) RNA; protein'. This two-step process is critical to gene expression, with transcription being the stage where DNA is copied into RNA, and translation being the process where the RNA sequence is used to create a specific protein. During transcription, an enzyme called RNA polymerase reads the sequence of DNA and synthesizes a complementary strand of messenger RNA (mRNA). Once the mRNA is produced, it is exported from the nucleus to a ribosome, where translation occurs. The ribosome reads the mRNA in codons, groups of three nucleotides, to assemble the corresponding amino acids into a polypeptide chain, ultimately folding into a functional protein.