OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

What occurs during transcription?

1. DNA is replicated into another DNA strand

2. Information in DNA is copied into mRNA

3. Amino acids are joined together to form proteins

4. mRNA is degraded in the nucleus

The correct answer is: Information in DNA is copied into mRNA

During transcription, the process involves copying the genetic information found in DNA into messenger RNA (mRNA). This is a crucial step in gene expression, as it allows the information encoded in the DNA to be translated into a functional product, usually a protein. In detail, during transcription, the DNA double helix unwinds and separates, and RNA polymerase enzyme synthesizes a single strand of mRNA using one of the DNA strands as a template. The resulting mRNA strand carries the genetic code from the DNA and subsequently moves from the nucleus to the cytoplasm, where it serves as a blueprint for protein synthesis during the next stage known as translation. This process is specific to the synthesis of RNA and marks a significant difference from DNA replication, where DNA is duplicated to create an identical copy. Other processes mentioned like amino acid joining or mRNA degradation are key to different cellular functions but do not occur during transcription itself.