Transcription and Translation Test - Genetics
what is the most abundant type of rna?
C) rRNA
a particular triplet of bases in the template of bases in the template strand of DNA is 5' AGT 3'. the corresponding codon for the mRNA transcribed is
A) 3' UCA 5'
RNA polymerase moves in which direction along the DNA?
A) 3ʹ → 5ʹ along the template strand
which of the following DNA mutations is the most likely to be damaging to the protein it specifies?
A) a base-pair deletion
When the ribosome reaches a stop codon on the mRNA, no corresponding tRNA enters the A site. If the translation reaction were to be experimentally stopped at this point, which of the following would you be able to isolate?
A) an assembled ribosome with a polypeptide attached to the tRNA in the P site
the anticodon of a particular tRNA molecule is
A) complementary to the corresponding mRNA codon
which of the following is not true of RNA processing?
A) exons are cut out before mRNA leaves the nucleus
What are polyribosomes?
A) groups of ribosomes reading a single mRNA simultaneously
the "universal" genetic code is now known to have exceptions. evidence for this could 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)
sickle-cell disease is probably the result of which kind of mutation?
A) point
the tata sequence is found only several nucleotides away from the start site of transcription. this most probably relates to which of the following?
A) the number of hydrogen bonds between A and T in DNA
As a ribosome translocates along an mRNA molecule by one codon, which of the following occurs?
A) the tRNA that was in the A site moves into the P site
Introns are significant to biological evolution because
A) their presence allows exons to be shuffled.
If proteins were composed of only 12 different kinds of amino acids, what would be the smallest possible codon size in a genetic system with four different nucleotides?
B) 2
choose the answer that has these events of protein synthesis in the proper sequence
B) 4, 1, 2, 5, 3
Which component is not directly involved in translation?
B) DNA
which of these is the function of a poly (A) signal sequence?
B) It codes for a sequence in eukaryotic transcripts that signals enzymatic cleavage ~10—35 nucleotides away
What are the coding segments of a stretch of eukaryotic DNA called?
B) exons
using RNA as a template for protein synthesis instead of translating proteins directly from the DNA is advantageous for the cell because
B) RNA acts as an expendable copy of the genetic material
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 of the following statements are true about protein synthesis in prokaryotes?
B) Translation can begin while transcription is still in progress
When translating secretory or membrane proteins, ribosomes are directed to the ER membrane by
B) a signal-recognition particle that brings ribosomes to a receptor protein in the ER membrane.
when does translation begin in prokaryotic cells?
B) as soon as transcription has begun
a mutation in which the following parts of a gene is likely to be most damaging to a cell?
B) exon
the process of translation, whether in prokaryotes or eukaryotes, requires tRNAs, amino acids, ribosomal subunits, and which of the following?
B) polypeptide factors plus GTP
in eukaryotic cells, transcription cannot begin until
B) several transcription factors have bound to the promoter.
the tRNA shown in figure 17.4 has its 3' end projecting beyond its 5' end. what will occur at this 3' end?
B) the amino acid binds covalently
There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that
B) the rules for base pairing between the third base of a codon and tRNA are flexible.
Each eukaryotic mRNA, even after post-transcriptional modification, includes 5' and 3' UTRs. Which are these?
B) the untranslated regions at either end of the coding sequence
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?
C) 5' TTT-CCC-AAA-GGG-TTT-CCC
the enzyme polynucleotide randomly assembles nucleotides into a polynucleotide polymer. you add polynucleotide phosphorylase to a solution of adenosine triphosphate and guanosine triphosphate. how many artificial mRna 3 nucleotide codons would be possible?
C) 8
the nitrogenous base adenine is found in all members of which group?
C) ATP, RNA, and DNA
A part of the promoter, called the TATA box, is said to be highly conserved in evolution. Which of the following might this illustrate?
C) Any mutation in the sequence is selected against.
The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following except
C) DNA was the first genetic material
Where does tRNA #2 move to after this bonding of lysine to the polypeptide?
C) E site
What is the effect of a nonsense mutation in a gene?
C) It introduces a premature stop codon into the mRNA.
During splicing, which molecular component of the spliceosome catalyzes the excision reaction?
C) RNA
in eukaryotes there are several different types of RNA polymerase. which type is involved in transcription of mRNA for a globin protein?
C) RNA polymerase II
which of the following is true for both prokaryotic and eukaryotic gene expression?
C) RNA polymerase binds to the promoter region to begin transcription
which of the following is (are) true of snRNPs?
C) They join together to form a large structure called the spliceosome.
A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is
C) UUU
Of the following, which is the most current description of a gene?
C) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide
What type of bonding is responsible for maintaining the shape of the tRNA molecule?
C) hydrogen bonding between base pairs
When a tRNA molecule is shown twisted into an L shape, the form represented is
C) its 3-dimensional shape.
an experimenter has altered the 3' end of the tRNA corresponding to the amino acid methionine in such a way as to remove the 3' AC. Which of the following hypotheses describes the most likely result?
C) the amino acid methionine will not bind
in the structural organization of many eukaryotic genes, individual exons may be related to which of the following?
C) the various domains of the polypeptide product
Using Figure 17.5, identify a 5'-->3' sequence of nucleotides in the DNA template strand for an mRNA coding for the polypeptide sequence Phe-Pro-Lys
D) 5'-CTTCGGGAA-3'
which of the following is not true of a codon?
D) It extends from one end of a tRNA molecule
in which of the following actions does RNA polymerase differ from the DNA polymerase?
D) RNA polymerase can initiate RNA synthesis, but DNA polymerase requires a primer to initiate DNA synthesis
Figure 17.4 represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine). Which codon on the mRNA strand codes for this amino acid?
D) UUC
In the 1920s Muller discovered that X-rays caused mutation in Drosophila. In a related series of experiments in the 1940s, Charlotte Auerbach discovered that chemicals-she used nitrogen mustards-have a similar effect. A new chemical food additive is developed by a cereal manufacturer. Why do we test for its ability to induce mutation?
D) We want to prevent any increase in mutation frequency.
which of the following nucleotide triplets best represents a codon
D) a triplet in the same reading frame as an upstream AUG
Once transcribed, eukaryotic mRNA typically undergoes substantial alteration that includes
D) excision of introns.
which component of the complex described enters the exit tunnel through the large subunit of the ribosome?
D) newly formed polypeptide
Transcription in eukaryotes requires which of the following in addition to RNA polymerase?
D) several transcription factors (TFs)
in an experimental situation a student researcher inserts an mRNA molecule into a eukaryotic cell after he has removed into 5' cap and poly(A) tail. which of the following would you expect him to find?
D) the molecule is digested by exonucleases since it is no longer protected at the 5' end
which of the following is a function of a signal peptide?
D) to translocate polypeptides across the ER membrane
which of the following mutations would be most likely to have a harmful effect on an organism?
E) a single nucleotide insertion downstream of, and close to, the start of the coding sequence
gene expression in Archaea differs from that in other prokaryotes. it shares features with which of the following?
E) bacteria and eukaryotes
Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the
E) bonding of the anticodon to the codon and the attachment of amino acids to tRNAs.
A frameshift mutation could result from
E) either an insertion or a deletion of a base
which enzyme causes a covalent bond to attach lysine to the polypeptide?
E) peptidyl transferase
what is the sequence of a peptide based on the following mRNA sequence?
E) phe-ser-tyr-cys-leu
From the following list, which is the first event in translation in eukaryotes?
E) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA