Test bank: Ch.17 Gene Expression Bio 1

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is _____.

3 UCA 5

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?

A) A gene from an organism can theoretically be expressed by any other organism.

Which of the following best describes the significance of the TATA box in eukaryotic promoters? A) It is the recognition site for a specific transcription factor. B) It sets the reading frame of the mRNA. C) It is the recognition site for ribosomal binding. D) Its significance has not yet been determined.

A) It is the recognition site for a specific transcription factor.

The release factor (RF) _____. A) binds to the stop codon in the A site in place of a tRNA B) releases the amino acid from its tRNA to allow the amino acid to form a peptide bond C) supplies a source of energy for termination of translation D) releases the ribosome from the ER to allow polypeptides into the cytosol

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

Once a peptide 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 occurs next? A) translocation B) reading of the next codon of mRNA C) initiation D) The codon-anticodon hydrogen bonds holding the tRNA in the A site are broken.

A) translocation

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

B) 2

How does termination of translation take place? A) The end of the mRNA molecule is reached. B) A stop codon is reached. C) The cap is reached. D) The poly-A tail is reached.

B) A stop codon is reached

Once researchers identified DNA as the unit of inheritance, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. What is the mechanism of information transfer in eukaryotes?

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

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

B) RNA polymerase II

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

B) RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.

Which one of the following statements about RNA processing is true? A) Exons are cut out before mRNA leaves the nucleus. B) Ribozymes may function in RNA splicing. C) RNA splicing can be catalyzed by tRNA. D) A primary transcript is often much shorter than the final RNA molecule that leaves the nucleus.

B) Ribozymes may function in RNA splicing.

Which of the following statements is true about protein synthesis in prokaryotes? A) Extensive RNA processing is required before prokaryotic transcripts can be translated. B) Translation can begin while transcription is still in progress. C) Prokaryotic cells have complicated mechanisms for targeting proteins to the appropriate cellular organelles. D) Unlike eukaryotes, prokaryotes require no initiation or elongation factors.

B) Translation can begin while transcription is still in progress.

A ribozyme is _____. A) a catalyst that uses RNA as a substrate B) an RNA with catalytic activity C) an enzyme that catalyzes the association between the large and small ribosomal subunits D) an enzyme that synthesizes RNA as part of the transcription process

B) an RNA with catalytic activity

Alternative RNA splicing _____. A) is a mechanism for increasing the rate of translation B) can allow the production of proteins of different sizes and functions from a single mRNA C) can allow the production of similar proteins from different RNAs D) increases the rate of transcription

B) can allow the production of proteins of different sizes and functions from a single mRNA

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

B) concurrent transcription and translation

What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure above? A) ionic bonding between phosphates B) hydrogen bonding between base pairs C) van der Waals interactions between hydrogen atoms D) peptide bonding between amino acids

B) hydrogen bonding between base pairs

A primary transcript in the nucleus of a eukaryotic cell is _____ the functional mRNA, while a primary transcript in a prokaryotic cell is _____ the functional mRNA. A) the same size as; smaller than B) larger than; the same size as C) larger than; smaller than D) the same size as; larger than

B) larger than; the same size as

Codons are part of the molecular structure of _____.

B) mRNA

Which of the following does not occur in prokaryotic gene expression, but does occur in eukaryotic gene expression? A) mRNA, tRNA, and rRNA are transcribed. B) RNA polymerase binds to the promoter. C) A cap is added to the 5' end of the mRNA. D) RNA polymerase requires a primer to elongate the molecule.

C) A cap is added to the end of the mRNA.

During elongation, which site in the ribosome represents the location where a codon is being read? A) E site B) P site C) A site D) the small ribosomal subunit

C) A site

Which one of the following, if missing, would usually prevent translation from starting? A) exon B) cap C) AUG codon D) poly-A tail

C) AUG codon

Of the following, which is the most current description of a gene? A) a unit of heredity that causes formation of a phenotypic characteristic B) a DNA subunit that codes for a single complete protein C) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide D) a discrete unit of hereditary information that consists of a sequence of amino acids

C) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide

A signal peptide _____. A) directs an mRNA molecule into the cisternal space of the ER B) terminates translation of messenger RNA C) helps target a protein to the ER D) signals the initiation of transcription

C) helps target a protein to the ER

According to the central dogma, what molecule should go in the blank? DNA → _____ → Proteins

C) mRNA

Translation requires _____. A) mRNA, tRNA, DNA, and rRNA B) mRNA, DNA, and rRNA C) mRNA, tRNA, and rRNA D) mRNA, tRNA, and DNA

C) mRNA, tRNA, and rRNA

Transcription in eukaryotes requires which of the following in addition to RNA polymerase? A) start and stop codons B) ribosomes and tRNA C) several transcription factors D) aminoacyl-tRNA synthetase

C) several transcription factors

Which of the following is directly related to a single amino acid?

C) the three-base sequence of mRNA

In the structural organization of many eukaryotic genes, individual exons may be related to which of the following? A) the sequence of the intron that immediately precedes each exon B) the number of polypeptides making up the functional protein C) the various domains of the polypeptide product D) the number of start sites for transcription

C) the various domains of the polypeptide product

Codons are three-base sequences that specify the addition of a single amino acid. How do eukaryotic codons and prokaryotic codons compare?

D) Codons are a nearly universal language among all organisms.

What does it mean when we say the genetic code is redundant?

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

Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the _____. A) binding of ribosomes to mRNA B) binding of the anticodon to small subunit of the ribosome C) attachment of amino acids to rRNAs D) binding of the anticodon to the codon and the attachment of amino acids to tRNAs

D) binding of the anticodon to the codon and the attachment of amino acids to tRNAs

Which of the following is the first event to take place in translation in eukaryotes? A) base pairing of activated methionine-tRNA to AUG of the messenger RNA B) binding of the larger ribosomal subunit to smaller ribosomal subunits C) covalent bonding between the first two amino acids D) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA

D) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA

In the process of transcription,

RNA is synthesized