Exam 17: Gene Expression: From Gene to Protein

Rank the following one-base point mutations with respect to their likelihood of affecting the structure of the corresponding polypeptide (from most likely to least likely). 1) insertion mutation deep within an intron 2) substitution mutation at the third position of a codon in an exon 3) substitution mutation at the second position of a codon in an exon 4) deletion mutation within the first exon of the gene

What would be the consequence of a mutation in a bacterial cell that produces a defective aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA?

In bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. Which of the following statements explains this fact?

Use the figure to answer the question. What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure?

Which of the following is not true of a codon?

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is ________.

Which of the following is not true of RNA processing?

The following question refers to this table of codons. Refer to the figure. Which of the triplets below is a possible anticodon for a tRNA that transports proline to a ribosome?

Once a peptide bond has been formed between the amino acid attached to the tRNA in the P site and the amino acid associated with the tRNA in the A site, what process occurs next?

Which of the following molecular structures contain codons?

Once researchers identified DNA as the molecule responsible for transmitting heritable traits, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. Which of the following statements correctly describes the mechanism of information transfer in eukaryotes that accomplishes this task?

Which of the following DNA mutations is most likely to damage the protein it specifies?

Which one of the following statements about RNA processing is correct?

Use the figure to answer the question. Refer to the metabolic pathway illustrated. If A, B, and C are all required for growth, a strain mutant for the gene encoding enzyme B would be able to grow on medium supplemented with which of the following nutrient(s)?

Which of the following statements correctly describes the function of a signal peptide?

Use the figure to answer the question. The figure shows a simple metabolic pathway. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway?

Which of the following processes occurs in prokaryotes but not in eukaryotes?

Use this model of a eukaryotic transcript to answer the following question. E = exon and I = intron 5′-UTR E₁ I₁ E₂ I₂ E₃ I₃ E₄ UTR-3′ Which components of the previous molecule will also be found in mRNA in the cytosol?

Which of the following processes occurs when termination of translation takes place?

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after she has removed its 5′ cap and poly-A tail. Which of the following processes would you expect her to find to have occurred?