BIO 101 Ch. 14 NVCC Study Guide

Given the locally unwound double strand in Figure 14.3, in which direction does the RNA polymerase move? A) 3' → 5' along the template strand B) 5' → 3' along the template strand C) 3' → 5' along the complementary strand D) 5' → 3' along the complementary strand E) 5' → 3' along the double-stranded DNA

A) 3' → 5' along the template strand

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5'-CCG-ACG-3' (mRNA). The charged transfer RNA molecules shown in Figure 14.4 (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form. The anticodon loop of the first tRNA that will complement this mRNA is A) 3'-GGC-5' B) 5'-GGC-3' C) 5'-ACG-3' D) 5'-UGC-3' E) 3'-UGC-5'

A) 3'-GGC-5'

A particular triplet of bases in the template strand of DNA is 5'-AGT-3'. The corresponding codon for the mRNA transcribed is A) 3'-UCA-5' B) 3'-UGA-5' C) 5'-TCA-3' D) 3'-ACU-5' E) either UCA or TCA, depending on wobble in the first base

A) 3'-UCA-5'

The genetic code is essentially the same for all organisms. Based on this information, one can logically assume which of the following statements to be correct? A) A gene from an organism can theoretically be expressed by any other organism B) All organisms have experienced convergent evolution C) DNA was the first genetic material D) The same codons in different organisms translate into the different amino acids E) Different organisms have different numbers of different types of amino acids

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

Which of the following DNA mutations is likely to have the most negative effect on the protein it specifies? A) a base-pair deletion B) a codon substitution C) a substitution in the last base of a codon D) a codon deletion

A) a base-pair deletion

The "universal" genetic code is now known to have exceptions. Evidence for this can be found if which of the following is true? A) if UGA, usually a stop codon, is found to code for an amino acid such as tryptophan (usually coded for by UGG only) B) if one stop codon, such as UGA, is found to have the same effect on translation as another stop codon, such as UAA C) if prokaryotic organisms are able to translate a eukaryotic mRNA and produce the same polypeptide D) if several codons are found to translate to the same amino acid, such as serine

A) if UGA, usually a stop codon, is found to code for an amino acid such as tryptophan (usually coded for by UGG only)

A eukaryotic transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that A) many noncoding stretches of nucleotides are present in eukaryotic DNA B) there is redundancy in the genetic code C) many nucleotides are needed to code for each amino acid D) there are termination exons near the beginning of mRNA

A) many noncoding stretches of nucleotides are present in eukaryotic DNA

RNA polymerase moves in which direction along the DNA? A) 5' to 3' along whichever strand it's on B) 3' to 5' along the template strand C) 5' to 3' along the template strand D) 5' to 3' along the double-stranded DNA E) 3' to 5' along the nontemplate strand

B) 3' to 5' along the template strand

Which of the following statements correctly describes alternative RNA splicing? A) It is a mechanism that can increase the rate of transcription B) It can allow the production of proteins of different sizes and functions from a single mRNA C) It allows the production of similar proteins from different RNAs D) It increases the rate of transcription

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

RNA polymerase in a prokaryote is composed of several subunits. Most of these subunits are the same for the transcription of any gene, but one, known as sigma, varies considerably. Which of the following is the most probable advantage for the organism in having such variability in RNA polymerase? A) It might allow the translation process to vary from one cell to another B) It might allow the polymerase to recognize different promoters under certain environmental conditions C) It might allow the polymerase to react differently to each stop codon D) It might alter the rate of translation and of exon splicing

B) It might allow the polymerase to recognize different promoters under certain environmental conditions

Which of the following statements best describes the termination of transcription in prokaryotes? A) RNA polymerase transcribes through the polyadenylation signal, causing proteins to associate with the transcript and cut it free from the polymerase B) RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript C) RNA polymerase transcribes through an intron, which causes the polymerase to let go of the transcript D) Once transcription has initiated, RNA polymerase transcribes until it reaches the end of the chromosome E) RNA polymerase transcribes through a stop codon, causing the polymerase to stop advancing through the gene and release the mRNA

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

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 multiple 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

Which small-scale mutation would be most likely to have the greatest negative effect on the functioning of a protein? A) a base substitution B) a base deletion near the start of a gene C) a base deletion near the end of the coding sequence, but not in the terminator codon D) deletion of three bases near the start of the coding sequence, but not in the initiator codon E) a base insertion near the end of the coding sequence, but not in the terminator codon

B) a base deletion near the start of a gene

When translating secretory or membrane proteins, ribosomes are directed to the ER membrane by A) a specific characteristic of the ribosome itself, which distinguishes free ribosomes from bound ribosomes B) a signal-recognition particle that brings ribosomes to a receptor protein in the ER membrane C) moving through a specialized channel of the nucleus D) a chemical signal given off by the ER E) a signal sequence of RNA that precedes the start codon of the message

B) a signal-recognition particle that brings ribosomes to a receptor protein in the ER membrane

What is a ribozyme? A) an enzyme that uses RNA as a substrate B) an RNA with enzymatic 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 E) an enzyme that synthesizes RNA primers during DNA replication

B) an RNA with enzymatic activity

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5'-CCG-ACG-3' (mRNA). The charged transfer RNA molecules shown in Figure 14.4 (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form. The dipeptide that will form will be A) cysteine-alanine B) proline-threonine C) glycine-cysteine D) alanine-alanine E) threonine-glycine

B) proline-threonine

In the transcription event of the DNA in Figure 14.3, where would the promoter be located? A) at the 3' end of the newly made RNA B) to the right of the template strand C) to the left of the template strand D) to the right of the sense strand E) to the left of the sense strand

B) to the right of the template strand

Examine the table of codons in Figure 14.2. A peptide has the sequence NH2-phe-pro-lys-gly-phe-pro-COOH. Which of the following sequences in the coding strand of the DNA could code for this peptide? A) 3'-UUU-CCC-AAA-GGG-UUU-CCC B) 3'-AUG-AAA-GGG-TTT-CCC-AAA-GGG C) 5'-TTT-CCC-AAA-GGG-TTT-CCC D) 5'-GGG-AAA-TTT-AAA-CCC-ACT-GGG E) 5'-ACT-TAC-CAT-AAA-CAT-TAC-UGA

C) 5'-TTT-CCC-AAA-GGG-TTT-CCC

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 poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end D) Transcription can begin as soon as translation has begun even a little E) RNA polymerase requires a primer to elongate the molecule

C) A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end

The nitrogenous base adenine is found in all members of which of the following groups of molecules? A) proteins, triglycerides, and testosterone B) proteins, ATP, and DNA C) ATP, RNA, and DNA D) glucose, ATP, and DNA E) proteins, carbohydrates, and ATP

C) ATP, RNA, and DNA

What is the effect of a nucleotide-pair substitution that results in a nonsense mutation in a gene? A) It changes an amino acid in the encoded protein B) It has no effect on the amino acid sequence of the encoded protein C) It introduces a premature stop codon into the mRNA D) It alters the reading frame of the mRNA

C) It introduces a premature stop codon into the mRNA

During splicing, which molecular component of the spliceosome catalyzes the excision reaction? A) protein B) DNA C) RNA D) lipid E) sugar

C) RNA

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is A) TTT B) UUA C) UUU D) AAA E) either UAA or TAA, depending on first base wobble

C) UUU

Of the following, which is the most current and complete 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 DNA-RNA sequence combination that results in an enzymatic product E) 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

Which of the following mutations is most likely to cause a phenotypic change? A) a duplication of all or most introns B) a nucleotide substitution in an exon coding for a transmembrane protein C) a single nucleotide deletion in an exon coding for an active site of a protein D) a frameshift mutation one codon away from the 3' end of the nontemplate strand

C) a single nucleotide deletion in an exon coding for an active site of a protein

Which of the following statements correctly describes the function of a signal peptide? A) It directs an mRNA molecule into the Golgi apparatus B) It causes RNA polymerase to bind DNA and initiate transcription C) It terminates translation of the messenger RNA D) It assists in the translocation of polypeptides across the ER membrane E) It leads the initiation of transcription

D) It assists in the translocation of polypeptides across the ER membrane

Which of the following is a function of a poly-A tail in mRNA? A) It adds the modified guanine to the 3' end of the mRNA B) It indicates the site of translational termination C) It is a sequence that codes for the binding of RNA polymerase to the DNA D) It helps protect the mRNA from degradation by hydrolytic enzymes

D) It helps protect the mRNA from degradation by hydrolytic enzymes

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after he has removed its 5' cap and poly-A tail. Which of the following would you expect him to find? A) The mRNA would not be transported out of the nucleus B) The cell recognizes the absence of the tail and adds a new poly-A tail to the mRNA C) The molecule is digested by restriction enzymes in the nucleus D) The molecule is degraded by hydrolytic enzymes because it is no longer protected at the 5' end and the 3' end E) The molecule attaches to a ribosome and is translated, but more slowly

D) The molecule is degraded by hydrolytic enzymes because it is no longer protected at the 5' end and the 3' end

The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the most likely result of this mutation in the protein product? A) a base-pair substitution B) a nucleotide mismatch C) a frameshift mutation D) a polypeptide missing an amino acid E) a nonsense mutation

D) a polypeptide missing an amino acid

Which of the following descriptions of nucleotide triplets best represents a codon? A) a triplet separated spatially from other triplets B) a triplet that has no corresponding amino acid C) a triplet at the opposite end of tRNA from the attachment site of the amino acid D) a triplet in the same reading frame as an upstream AUG E) a sequence in tRNA at the 3' end

D) a triplet in the same reading frame as an upstream AUG

Accuracy in the translation of mRNA into the sequence of amino acids in a polypeptide depends on specificity in which of the following? A) binding of ribosomes to mRNA B) shape of the A and P sites of ribosomes C) attachment of amino acids to tRNAs D) bonding of the anticodon to the codon and the attachment of amino acids to tRNAs

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

In order for a eukaryotic gene to be engineered into a bacterial colony to be expressed, what must be included in addition to the coding exons of the gene? A) the introns B) eukaryotic polymerases C) a bacterial promoter sequence D) eukaryotic ribosomal subunits E) eukaryotic tRNAs

D) eukaryotic ribosomal subunits

Garrod hypothesized that inherited diseases such as alkaptonuria, the inability to metabolize the chemical alkapton, occur because A) metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies B) many metabolic enzymes use DNA as a cofactor, and affected individuals have mutations that prevent their enzymes from interacting efficiently with DNA C) certain metabolic reactions are carried out by ribozymes, and affected individuals lack key splicing factors D) genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes

D) genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes

Examine the table of codons in Figure 14.2. What amino acid sequence will be produced based on the following mRNA codon sequence? 5'-AUG-UCU-UCG-UUA-UCC-UUG-3' A) met-arg-glu-arg-glu-arg B) met-glu-arg-arg-glu-leu C) met-ser-leu-ser-leu-ser D) met-ser-ser-leu-ser-leu E) met-leu-phe-arg-glu-glu

D) met-ser-ser-leu-ser-leu

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

D) several transcription factors

Examine the table of codons in Figure 14.2. A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be A) 5'-TTG-CTA-CAG-TAG-3' B) 3'-AAC-GAC-GUC-AUA-5' C) 5'-AUG-CTG-CAG-TAT-3' D) 3'-AAA-AAT-ATA-ACA-5' E) 3'-AAA-GAA-TAA-CAA-5'

E) 3'-AAA-GAA-TAA-CAA-5'

In comparing DNA replication with RNA transcription in the same cell, which of the following is true only of replication? A) It uses RNA polymerase B) It makes a new molecule from its 5' end to its 3' end C) The process is extremely fast once it is initiated D) The process occurs in the nucleus of a eukaryotic cell E) The entire template molecule is represented in the product

E) The entire template molecule is represented in the product

Which of the following types of mutations could result in a frameshift mutation? A) a base insertion only B) a base deletion only C) a base substitution only D) deletion of three consecutive bases E) either an insertion or a deletion of a base

E) either an insertion or a deletion of a base