Chapter 12 Gene Expression EZ Test
The most common eukaryotic ribosome carries out its function in the.
Cyrosol
In eukaryotes, 40S and 60S combine to form a 100S ribosome.
False
A(n) ______ is an organized unit of DNA sequences that enables a segment of DNA to be transcribed into RNA and ultimately results in the formation of a functional product.
Gene
Which of the following statements about RNA processing in eukaryotes is INCORRECT?
Introns are simply excised out of pre-mRNA to produce the mature mRNA.
Which of the following statements about RNA polymerase in bacteria is INCORRECT?
It catalyzes the addition of nucleotides to the 5′end of a growing RNA strand.
The following codons and the amino acids they encode is as follows: AUG = Start or Met; UUU, UUC = Phe; UUA, UUG = Leu; UCU, UCC = Ser; CCU, CCC = Pro; ACU, ACC = Thr; UGA = Stop. The 5′ACU-UUC-ACU-AUG-UUU-UUA-UCC-UCC-ACU-CCU-UGA3′ mRNA transcript results in which of the following polypeptide sequences?
Met-Phe-Leu-Ser-Ser-Thr-Pro
An mRNA sequence is 5′AUG-GGC-ACU-CAU-ACU-UAA3′, where AUG is the start codon and UAA is the stop codon. How many distinct aminoacyl-tRNA synthetases are required to translate the mRNA sequence?
4
If a DNA template strand has a sequence of 3′ TACAATGTAGCC 5′, then the RNA produced from it will be which sequence?
5′AUGUUACAUCGG3'
________ is directly produced from the transcription of a eukaryotic gene.
pre-mRNA
Transcription begins near a site in the DNA called the ______, while the terminator specifies the end of transcription.
promoter
Which of the following serves as the "translator" or intermediary between an mRNA codon and an amino acid?
tRNA
Which of the following statements about tRNA is FALSE?
tRNAs can be spliced by splicesomes.
Which of the following are products of nonstructural genes, and are therefore never translated?
transfer RNA and ribosomal RNA
What is the function of the poly A tail?
The poly A tail increases mRNA stability in eukaryotes.
Which of the following statements about the mRNA start codon is INCORRECT?
The start codon is usually GGA.
What enzyme catalyzes the attachment of amino acids to tRNA molecules?
aminoacyl-tRNA synthetase
Because more than one codon can specify the same amino acid, the genetic code is said to be
degenerate.
The processes of transcription and translation are collectively known as
gene expression.
Intervening sequences that are transcribed, but not translated into protein are called
introns.
The termination of translation occurs when a release factor recognizes the stop codon.
True
Which of the following proteins is involved in synthesizing messenger RNA in eukaryotes?
RNA polymerase II
________ is to transcription as ________ are to translation?
RNA polymerase; ribosomes
The process that produces mRNA from DNA is called
transcription
Which protein influences the ability of RNA polymerase to transcribe genes?
transcription factors
If an mRNA sequence is 5′AUG-GGC-ACU-CAU3′, what would the anticodon sequence be?
3′UAC-CCG-UGA-GUA5′
How many nucleotides are contained in a single codon?
3
________ enables a single gene to encode two or more polypeptides that are different in their amino acid sequence.
Alternative splicing
The term N-terminus refers to the presence of a(n) ________ at the 5′ end of a polypeptide.
Amino Group
A ________ bond holds the amino acids of a growing polypeptide chain together during the elongation stage of translation.
Peptide
On which of the following processes would a defective ribosome have the most detrimental effect?
Translation
DNA is used as a template to make mRNA, which contains the information to make a polypeptide.
True
More than one codon can specify the same amino acid.
True
RNA polymerase II of eukaryotes always requires more than one general transcription factor to initiate transcription.
True
Which of the following regions of a structural gene contains the information that specifies an amino acid sequence?
transcribed region
