Question

1. a student argues that mrna is unnecessary in protein synthesis because dna already carries the genetic code. which response best explains why the students model is inaccurate? mrna carries the dna code to the ribosome, where proteins are built. dna can leave the nucleus, so mrna is not needed. trna makes copies of dna directly in the cytoplasm. proteins are assembled in the nucleus without rna. clear all

Explanation:

• mRNA (messenger RNA) is crucial in protein synthesis. DNA is located in the nucleus and cannot leave it. mRNA is transcribed from DNA in the nucleus and then travels to the ribosome (in the cytoplasm) where protein synthesis occurs. It carries the genetic code (from DNA) to the ribosome.
• DNA cannot leave the nucleus, so the statement “DNA can leave the nucleus, so mRNA is not needed” is wrong.
• tRNA (transfer RNA) does not make copies of DNA. tRNA brings amino acids to the ribosome during translation.
• Proteins are assembled at the ribosome (in the cytoplasm), not in the nucleus, and RNA (including mRNA, tRNA, rRNA - ribosomal RNA) is essential for protein synthesis.

Answer:

mRNA carries the DNA code to the ribosome, where proteins are built.