Ch. 17 Gene to protein

Which of the following statements best supports the one gene-one enzyme hypothesis?

A mutation in a single gene can result in a defective protein.

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

simultaneous transcription and translation of the same mRNA

A particular triplet of bases in the coding sequence of DNA is 5'-AAA-3'. The anticodon on the tRNA that binds the mRNA codon is ________.

3′-AAA-5′

An mRNA molecule with the sequence 5′-CCG-ACG-3′is being read by a ribosome. During translation which of the following tRNA anticodons will be the first to productively bind with this mRNA?

3′-GGC-5′

What is the function of the release factor during translation in eukaryotes?

It binds to the stop codon in the A site in place of a tRNA.

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

It helps target a protein to the ER.

Which of the following statements best describes the significance of the TATA box in the promoters of eukaryotes?

It is the recognition site for the binding of a specific transcription factor.

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 that accomplishes this task in eukaryotes?

Messenger RNA is transcribed from a single gene and transfers information to the cytoplasm, where protein synthesis takes place.

Which of the following best describes the redundancy in the genetic code?

More than one codon can specify the addition of the same amino acid.

Which answer correctly compares prokaryotic and eukaryotic codons?

Organisms utilize codons that are nearly universal among all organisms.

Which of the following processes occurs as part of transcription?

RNA is synthesized

In eukaryotes, there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a protein?

RNA polymerase II

Which of the following statements best describes the termination of transcription in prokaryotes?

RNA polymerase transcribes to the terminator sequence, causing the polymerase to separate from the DNA and release the transcript

Which of the following characteristics of gene expression is shared by eukaryotic and prokaryotic cells?

Signal sequences are needed for the production of membrane proteins.

Accuracy in translation of mRNA into the primary structure of a polypeptide depends on specificity in the ________.

attachment of amino acids to tRNAs

According to the central dogma, which of the following intermediate molecules correctly completes the flow chart describing the flow of information in a cell blank? DNA → ________ → Proteins

mRNA

Which of the following molecular structures contains codons?

mRNA

Which of the following molecules carries information from DNA and directs incorporation of amino acids at the ribosome?

mRNA

If a bacteria contained a mutant aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA which of the following would occur?

proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU

Which answer correctly compares the primary transcript in the nucleus of a eukaryotic cell with the functional mRNA?

the primary transcript is larger than the mRNA

Which answer correctly compares the primary transcript in a prokaryotic cell with the functional mRNA?

the primary transcript is the same size as the mRNA

Which of the following best explains the observation that in bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs?

the rules for base pairing between the third base of a codon and tRNA are flexible

In eukaryotes which of the following is the first step in translation?

the small subunit of the ribosome recognizes and attaches near the 5' cap of mRNA

Which of the following characteristics is directly related to the coding of a single amino acid during the process of translation?

the three-base sequence of mRNA

Transcription in eukaryotes requires which of the following molecules in addition to RNA polymerase?

transcription factors