What occurs during transcription?

During transcription, the DNA sequence is specifically copied into messenger RNA (mRNA). This process begins with the enzyme RNA polymerase binding to a specific region of the DNA at the promoter. The DNA unwinds and unzips, allowing the RNA polymerase to read the template strand of the DNA. As it moves along the DNA, it synthesizes a single strand of RNA that is complementary to the DNA template. The resulting mRNA molecule then carries the genetic instructions from the DNA in the nucleus to the ribosomes, where it can be translated into proteins.

The other options refer to processes that are distinct from transcription. For example, the translation of mRNA into protein happens after transcription has already occurred. Chromosome replication involves duplicating the entire chromosome, which is a separate event that ensures both daughter cells receive an identical set of DNA during cell division. Gene mutations refer to permanent alterations in the DNA sequence, which can occur independently of the transcription process and can result from various factors such as environmental influences or errors during DNA replication.