A Level Biology Practice Exam

Which molecule is primarily involved in carrying genetic information from the nucleus to the ribosome?

1. DNA

2. mRNA

3. tRNA

4. rRNA

The correct answer is: mRNA

The molecule primarily responsible for carrying genetic information from the nucleus to the ribosome is mRNA, or messenger RNA. During the process of transcription, a specific segment of DNA is transcribed to produce mRNA, which serves as a complementary copy of the gene. This mRNA then exits the nucleus and travels to the ribosome, where it serves as a template for protein synthesis during translation. mRNA's role is crucial in the flow of genetic information, following the central dogma of molecular biology, which states that DNA is transcribed into RNA, which is then translated into protein. This makes mRNA the key player in transporting genetic instructions necessary for assembling amino acids into proteins. Each codon on the mRNA corresponds to a specific amino acid, guiding the ribosome in its assembly process. Other types of RNA, such as tRNA (transfer RNA) and rRNA (ribosomal RNA), play different roles in protein synthesis. tRNA brings the appropriate amino acids to the ribosome based on the sequence of the mRNA, while rRNA is a component of the ribosome itself, providing structural and catalytic functions, but neither carries genetic information. Thus, mRNA is uniquely positioned at the interface between the genetic code in DNA and the synthesis