DNA and protein synthesis：练习题

In eukaryotes, a specific gene contains both exons and introns. During the first stage of protein synthesis, RNA polymerase transcribes the entire gene. What is the immediate product of this process, and how is it modified before it can be used for translation?

A messenger RNA (mRNA) molecule has a different structure compared to a transfer RNA (tRNA) molecule. Which of the following is a structural feature unique to tRNA?

In eukaryotic protein synthesis, the transcription of a gene produces pre-mRNA. Which statement accurately describes the processing of this molecule before translation occurs?

Which of the following statements correctly identifies a structural feature of transfer RNA (tRNA) that is essential for its role in translation?

A polypeptide is produced during translation from an mRNA sequence. Which of the following statements correctly describes the role of ATP in this process?

In eukaryotes, transcription leads to the production of pre-mRNA. Explain why splicing is a necessary step before this molecule can be used in translation.

During translation, an mRNA codon is \( 5'-AUG-3' \). State the corresponding anticodon sequence found on the tRNA molecule and the orientation of its bases.

In eukaryotic protein synthesis, transcription occurs in the nucleus. Explain how the structure of DNA allows for the production of a pre-mRNA molecule that carries the exact same genetic information as the coding strand of the gene.

A specific segment of eukaryotic DNA has a base sequence that is transcribed into pre-mRNA and then processed.

a) Explain the difference between the genome and the proteome of a cell. (2 points)
b) Describe how the structure of pre-mRNA is modified to produce mRNA in a eukaryotic nucleus. (1 point)

Protein synthesis is a highly regulated process involving the transfer of genetic information from the nucleus to the cytoplasm. In eukaryotic cells, this involves several stages and modifications.

a) Describe the process of transcription in the nucleus and explain how the structure of the resulting pre-mRNA is modified to produce mRNA. (3 points)

b) Contrast the structure of tRNA with the structure of mRNA, specifically focusing on the presence of hydrogen bonds and the overall shape of the molecule. (2 points)

c) A mutation occurs in a gene where a single nucleotide is deleted. Explain why this deletion typically has a more significant effect on the structure of the resulting polypeptide than a base substitution mutation. (2 points)