Question 21

mRNA carries the genetic code copied from DNA.

Messenger RNA (mRNA) is the type of RNA that conveys genetic information from DNA to the ribosome, where proteins are synthesized. It serves as a template for protein synthesis, making it essential for translating the genetic code.

A) mRNA

This option is correct because mRNA is specifically designed to carry the genetic code from the DNA in the nucleus to the ribosomes in the cytoplasm, where proteins are produced. It undergoes transcription to create a complementary strand that mirrors the sequence of the DNA.

B) tRNA

Transfer RNA (tRNA) is not the correct answer as its primary function is to transport amino acids to the ribosome during protein synthesis rather than carrying the genetic code. tRNA recognizes specific codons on the mRNA and matches them with the appropriate amino acids.

C) rRNA

Ribosomal RNA (rRNA) is also not the correct choice because it is a structural component of ribosomes and plays a role in protein synthesis but does not carry genetic information. rRNA helps facilitate the translation process but does not serve as a template for the genetic code.

D) None of the above

This option is incorrect because mRNA is indeed the type of RNA that carries the genetic code from DNA. Therefore, stating that none of the options are correct is misleading, as mRNA fulfills this specific role.

Conclusion

mRNA is the definitive answer as it is the sole type of RNA responsible for carrying the genetic code from DNA to the ribosome for protein synthesis. Both tRNA and rRNA serve different functions in the process of translation, while the option "None of the above" fails to acknowledge the role of mRNA. Thus, mRNA is essential for translating genetic information into functional proteins.