Question

the transcription of a dna molecule into an mrna molecule, and the translation of that mrna molecule, can occur simultaneously in prokaryotic cells. this does not occur in eukaryotic cells. which statement explains why transcription and translation can occur simultaneously in prokaryotic cells but not in eukaryotic cells? prokaryotic cells have more mitochondria to produce energy. prokaryotic cells lack a nucleus to separate the two processes. eukaryotic cells do not create amino acids until transcription is complete. eukaryotic cells lack ribosomes to translate the mrna for protein synthesis.

Explanation:

• Prokaryotic cells lack a nucleus. Transcription occurs in the cytoplasm, and ribosomes (for translation) are also in the cytoplasm. So, transcription and translation can happen simultaneously.
• Eukaryotic cells have a nucleus. Transcription occurs in the nucleus, and mRNA must be transported to the cytoplasm (where ribosomes are) for translation. So, the two processes are separated in space and time.
• Option A: Prokaryotic cells do not have mitochondria.
• Option C: Amino - acid synthesis is not the reason for the separation of transcription and translation.
• Option D: Eukaryotic cells have ribosomes.

Answer:

B. Prokaryotic cells lack a nucleus to separate the two processes.