Why do eukaryotic mRNA molecules require a 5' cap and a poly-A tail, whereas prokaryotic mRNA does not?

• A. Eukaryotic mRNA is synthesized in the cytoplasm, where it is immediately translated, requiring additional modifications.
• B. Prokaryotic mRNA is longer and does not require additional modifications for stability.
• C. Prokaryotic mRNA is more stable and does not degrade easily, eliminating the need for a 5' cap and poly-A tail.
• D. Eukaryotic mRNA is processed in the nucleus and requires protection during transport to the cytoplasm.

Answer: (D)

Verified step by step guidance

1. Understand the structure and function of mRNA in eukaryotic cells. Eukaryotic mRNA is synthesized in the nucleus and must be transported to the cytoplasm for translation.
2. Recognize the role of the 5' cap in eukaryotic mRNA. The 5' cap is a modified guanine nucleotide added to the beginning of the mRNA molecule, which protects the mRNA from degradation and assists in ribosome binding during translation.
3. Learn about the poly-A tail in eukaryotic mRNA. The poly-A tail is a sequence of adenine nucleotides added to the 3' end of the mRNA, which enhances stability and facilitates export from the nucleus.
4. Compare eukaryotic and prokaryotic mRNA processing. Prokaryotic mRNA is synthesized in the cytoplasm and is immediately available for translation, thus it does not require the same modifications for stability and transport.
5. Understand why prokaryotic mRNA does not need a 5' cap and poly-A tail. Prokaryotic mRNA is generally more stable and does not degrade as easily, eliminating the need for these protective modifications.