A Level Biology Practice Exam

What is the process through which messenger RNA (mRNA) is produced?

1. Translation

2. Transcription

3. Replication

4. Binary fission

The correct answer is: Transcription

The correct answer is indeed the process of transcription. During transcription, the genetic information encoded in DNA is copied into messenger RNA (mRNA). This occurs in the nucleus of eukaryotic cells and involves several steps: 1. **Initiation**: RNA polymerase binds to a specific region of DNA at the promoter, unwinding the DNA strands. 2. **Elongation**: RNA polymerase synthesizes the mRNA strand by adding complementary RNA nucleotides that are paired with the DNA template strand. 3. **Termination**: The process continues until RNA polymerase reaches a termination sequence, signaling the end of transcription. Transcription is crucial because it serves as the first step in gene expression, allowing the information stored in DNA to be transcribed into a format (mRNA) that can be translated into proteins. In contrast, other processes listed, such as translation, replication, and binary fission, serve different functions in cellular biology. Translation is the process where the mRNA is deciphered by ribosomes to synthesize proteins, replication refers to the duplication of DNA, and binary fission is a method of asexual reproduction in prokaryotic organisms. This contextual understanding underscores why transcription is the correct answer to the question