Deck 15: Gene Expression: From Dna to Protein

Question 1

The ____ , located ____ of the transcription start point, is the site at which RNA polymerase associates with DNA to begin transcription.

A) promoter; upstream
B) initiator; downstream
C) initiator; upstream
D) promoter; downstream
E) intron; downstream

Answer 1

A

Question 2

Srb and Horowitz's research led to the ____ hypothesis, which has since been modified to the ____ hypothesis.

A) one gene-one enzyme; one gene-one polypeptide
B) one gene-one polypeptide; one gene-one enzyme
C) one gene-one protein; one gene-one enzyme
D) one gene-one polypeptide; one gene-one protein
E) one gene-one enzyme; one gene-one protein

Answer 2

A

Question 3

Enzymes are ____.

A) lipid molecules
B) proteins
C) DNA molecules
D) transposable elements
E) codons

Answer 3

B

Question 4

Consider a mutant organism that is unable to make the amino acid arginine. Knowing that the metabolic pathway for arginine production is ornithine ->citrulline ->arginine, you test the ability of the mutant to grow in the presence of just one of these compounds. You find that the mutant can grow in the presence of arginine, but not in the presence of citrulline or ornithine. From this, you can conclude that the product of the mutant gene is most directly involved in the production of ____.

A) arginine from ornithine
B) arginine from citrulline
C) citrulline from ornithine
D) ornithine from arginine
E) citrulline from arginine

Question 5

Beadle and Tatum used nutritional mutants called ____ to study the relationship between genes and proteins in Neurospora .

A) transposons
B) chaperones
C) polysomes
D) auxotrophs
E) wild types

Question 6

The TATA box is a key element of the ____ of most eukaryotic protein-coding genes.

A) terminator
B) coding region
C) promoter
D) transcription start point
E) introns

Question 7

The central dogma describes the flow of information of gene expression as ____.

A) DNA ->RNA ->protein
B) RNA ->DNA
C) RNA ->DNA ->protein
D) protein ->DNA ->RNA
E) DNA ->protein ->RNA

Question 8

Proteins called transcription factors are involved in ____ of transcription.

A) both initiation and termination stages
B) both initiation and elongation stages
C) the termination stage
D) the initiation stage
E) the initiation, elongation, and termination stages

Question 9

Which bases are found in RNA?

A) adenine and uracil only
B) adenine, thymine, and cytosine only
C) adenine, uracil, and cytosine only
D) adenine, uracil, guanine, and cytosine
E) adenine, thymine, guanine, and cytosine

Question 10

With minor exceptions, the genetic code ____.

A) is the same for all living organisms and viruses
B) is specialized so that viruses use a different code from all living organisms
C) differs between different organisms and viruses
D) is the same for all viruses and for single-celled organisms, but is more complex in multicellular organisms
E) has three versions: one for viruses, one for single-celled organisms, and one for multicellular organisms

Question 11

The process of translation refers to the use of information encoded in ____ to make ____.

A) RNA; a complementary DNA copy
B) DNA; a polypeptide
C) DNA; a complementary RNA copy
D) a polypeptide; RNA
E) RNA; a polypeptide

Question 12

The genetic code is said to be degenerate because ____.

A) some codons do not specify an amino acid
B) most amino acids are represented by more than one codon
C) the code varies considerably between different organisms
D) the code is commaless with no indicators of spaces between codons
E) the code varies considerably between different cell types within a multicellular organism

Question 13

Protein-encoding genes in eukaryotes are transcribed by ____.

A) RNA polymerase I
B) RNA polymerase II
C) RNA polymerase III
D) either RNA polymerase I or III
E) either RNA polymerase II or III

Question 14

Transcription is terminated in prokaryotes by ____.

A) generation of a stop codon
B) transcription of an mRNA terminator sequence
C) splicing introns out and pasting exons together
D) generation of a guanine cap
E) generation of a poly-A tail

Question 15

The process of transcription refers to the use of information encoded in ____ to make ____.

A) RNA; a complementary DNA copy
B) DNA; a polypeptide
C) DNA; a complementary RNA copy
D) a polypeptide; RNA
E) RNA; a polypeptide

Question 16

During transcription, ____.

A) double-stranded RNA chains are produced
B) the entire DNA molecule is copied to RNA
C) primase creates an RNA primer to start the RNA strand
D) only one of the two DNA strands acts as a template
E) protein is made from RNA

Question 17

Every protein is assembled on a(n) ____ according to instructions copied from ____, using ____ as an intermediate.

A) mRNA; tRNA; DNA
B) tRNA; mRNA; DNA
C) ribosome; mRNA; tRNA
D) tRNA; DNA; mRNA
E) ribosome; DNA; mRNA

Question 18

In both prokaryotes and eukaryotes, the start codon (or initiator codon) is ____, which codes for the amino acid ____.

A) UGA; proline
B) UUU; phenylalanine
C) AAA; lysine
D) ACG; threonine
E) AUG; methionine

Question 19

Except for the stop codons, the codons in the genetic code specify which of the ____ amino acids will be added to a growing polypeptide chain.

A) 5
B) 64
C) 4
D) 20
E) 3

Question 20

During the elongation stage of transcription ____.

A) DNA nucleotides are added to the transcript
B) the transcript grows in the 5'->3' direction
C) transcription factors recruit RNA polymerase to the template strand
D) the double helix remains single-stranded after being used as a template
E) RNA polymerase binds to the promoter region

Question 21

In which process are existing protein regions or domains mixed in novel combinations to produce new proteins?

A) alternative splicing
B) degeneracy
C) exon shuffling
D) the wobble hypothesis
E) aminoacylation

Question 22

The pre-mRNA transcript of mammalian α-tropomyosin undergoes ____ to produce different mRNAs in smooth and striated muscles.

A) aminoacylation
B) alternative splicing
C) polyadenylation
D) degeneracy
E) exon shuffling

Question 23

The number of proteins humans can produce vastly exceeds the number of genes in the human genome. This is best explained by ____.

A) aminoacylation
B) exon shuffling
C) the wobble hypothesis
D) degeneracy
E) alternative splicing

Question 24

A ribosome consists of ____.

A) two small subunits
B) two large subunits
C) three subunits of different size
D) rRNA and ribosomal proteins
E) tRNA and ribosomal proteins

Question 25

The regions retained in finished mRNA transcripts after pre-mRNA processing are called ____.

A) spliceosomes
B) snRNPs
C) exons
D) domains
E) introns

Question 26

Small ribonucleoprotein particles (snRNPs) are involved in ____.

A) mRNA splicing
B) initiation of transcription
C) aminoacylation of tRNA
D) initiation of translation
E) termination of translation

Question 27

The cap on an mRNA transcript is the site where ____.

A) ribosomes attach at the start of translation
B) the start codon is located
C) translation is terminated
D) the stop codon is covered until needed
E) the 3' end of the mRNA is protected from attack by RNA-digesting enzymes

Question 28

The region in a tRNA molecule that base-pairs with mRNA during translation is the ____.

A) anticodon
B) aminoacylation site
C) TATA box
D) cloverleaf
E) reading frame

Question 29

The antibiotics streptomycin and erythromycin work by inhibiting the function of ____ in bacteria, but not eukaryotes.

A) RNA polymerases
B) aminoacyl-tRNA synthetases
C) spliceosomes
D) DNA polymerases
E) ribosomes

Question 30

In the process of mRNA splicing, the lariat structure is the ____.

A) splicing complex
B) region where two exons are pasted together
C) enzyme that cuts the pre-mRNA
D) released intron
E) region where two introns are pasted together

Question 31

Figure 15.1
The structure in the figure above represents a molecule of ____.

A) pre-mRNA
B) tRNA
C) snRNA
D) mRNA
E) rRNA

Question 32

The complete set of 61 sense codons can be read by fewer than 61 distinct tRNA molecules according to ____.

A) alternative splicing
B) degeneracy
C) exon shuffling
D) the wobble hypothesis
E) aminoacylation

Question 33

The formation of peptide bonds during translation is catalyzed by ____ found in the ____.

A) RNA polymerase; large ribosomal subunit
B) peptidyl transferase; small ribosomal subunit
C) peptidyl transferase; large ribosomal subunit
D) aminoacyl-tRNA synthetase; small ribosomal subunit
E) aminoacyl-tRNA synthetase; tRNA

Question 34

For most eukaryotic genes, translation begins in the____.

A) cytoplasm
B) nucleolus
C) nucleus
D) mitochondria
E) Golgi apparatus

Question 35

The process of linking the correct amino acid to a tRNA molecule is catalyzed by ____.

A) the tRNA itself
B) RNA polymerase
C) an mRNA
D) the ribosome
E) an aminoacyl-tRNA synthetase

Question 36

The process of removing introns from mRNA and joining exons together occurs in a complex called the ____.

A) ribosome
B) anticodon
C) lariat
D) polysome
E) spliceosome

Question 37

The poly(A) tail of an mRNA ____.

A) is where the start codon is located
B) covers the stop codon until it is needed
C) protects the 3' end of the mRNA from attack by RNA-digesting enzymes
D) is where ribosomes attach at the start of translation
E) is where translation terminates

Question 38

Pre-mRNA is modified on its 5' end by ____.

A) exon shuffling
B) the addition of a poly(A) tail
C) mRNA splicing
D) the addition of a guanine cap
E) aminoacylation

Question 39

In an mRNA transcript, the 3' UTR refers to the region of the mRNA that is ____.

A) upstream from the start codon
B) upstream from the site for initiation of transcription
C) downstream from the stop codon
D) the coding region
E) downstream from the site for termination of transcription

Question 40

Pre-mRNA is found____.

A) only in prokaryotes
B) in both the nucleus and cytoplasm of eukaryotes
C) only in the cytoplasm of eukaryotes
D) in both prokaryotes and eukaryotes
E) only in the nucleus of eukaryotes

Question 41

The ribosome binding site in an mRNA transcript is located ____ and is where ____.

A) at the start codon; the large ribosomal subunit binds to the mRNA-tRNA complex in prokaryotes
B) just upstream of the start codon; the large ribosomal subunit binds to mRNA in eukaryotes
C) at the start codon; the small ribosomal subunit binds to the mRNA-tRNA complex in eukaryotes
D) on aminoacyl-tRNA; the large ribosomal subunit binds to tRNA in prokaryotes
E) just upstream of the start codon; the small ribosomal subunit binds to mRNA in prokaryotes

Question 42

Initiation factors are ____ that assist in the initiation of translation.

A) mRNAs
B) proteins
C) tRNAs
D) amino acids
E) snRNPs

Question 43

Substitution of one base pair for another in a coding region of a gene can result in a ____ mutation where the changed codon specifies a different amino acid.

A) missense
B) chromosomal
C) frameshift
D) silent
E) nonsense

Question 44

Substitution of one base pair for another in a coding region of a gene can result in a ____ mutation where a codon specifying an amino acid is changed to a stop codon.

A) missense
B) chromosomal
C) frameshift
D) silent
E) nonsense

Question 45

The routing of proteins to their final destinations in eukaryotic cells is ____.

A) essentially random
B) based on transcription factors
C) controlled by the type of ribosome used
D) directed by signals that are part of the proteins
E) primarily determined by mRNA splicing

Question 46

If a codon in the mRNA is 5'-ACG-3', then the anticodon of the proper tRNA will be ____.

A) 5'-UGC-3'
B) 3'-CGU-5'
C) 5'-CGT-3'
D) 3'-CGT-5'
E) 5'-GCA-3'

Question 47

During translation, tRNAs bind to mRNA through ____.

A) ionic bonds
B) van der Waals forces
C) nonpolar covalent bonds
D) hydrogen bonds
E) polar covalent bonds

Question 48

Helper proteins that assist in protein folding are called ____.

A) snRNPs
B) molecular chaperones
C) ribosomes
D) spliceosomes
E) polysomes

Question 49

Translation ends when a stop codon in the ____ site allows a ____ to bind there.

A) P; release factor
B) A; terminator tRNA
C) E; terminator tRNA
D) A; release factor
E) P; terminator tRNA

Question 50

Substitution of one base pair for another in the coding region of a gene can result in a ____ mutation where the changed codon still specifies the same amino acid.

A) missense
B) chromosomal
C) frameshift
D) silent
E) nonsense

Question 51

Proteins that function in the cytosol are synthesized ____.

A) on free ribosomes in the cytosol
B) on the rough ER before being transported to the cytosol
C) in the Golgi apparatus
D) on the rough ER before being transported to the Golgi apparatus
E) in the nucleus before being transported to the cytosol

Question 52

The reading frame for translation is established by ____.

A) removal of the cap from the mRNA
B) pairing of the initiator tRNA with the start codon
C) the first base in the mRNA molecule
D) the ribosome binding site
E) the poly(A) tail

Question 53

Insertion of two bases into the coding region of a gene just after the start codon of a gene will result in a ____ mutation.

A) missense
B) chromosomal
C) frameshift
D) silent
E) nonsense

Question 54

At the start of translation, the initiator tRNA pairs with the start codon at the ____ of the ribosome.

A) A (aminoacyl) site
B) promoter
C) P (peptidyl) site
D) ribosomal binding site
E) E (exit) site

Question 55

Which region(s) of the ribosome accept(s) charged tRNA molecules during the elongation phase of translation?

A) the A site
B) the A site or the E site
C) the P site
D) the P site or the E site
E) the E site

Question 56

A polysome is ____.

A) the combination of a large and a small ribosomal subunit
B) the complex where mRNA splicing occurs
C) the promoter assembly at the site of transcription initiation
D) an mRNA transcript to which multiple ribosomes are attached
E) the complex that adds a poly(A) tail onto an mRNA

Question 57

Relative to the mRNA, which of the following moves during translocation?

A) attached tRNAs and the ribosome
B) attached tRNAs and the polypeptide chain
C) the ribosome only
D) the ribosome and the polypeptide chain
E) the polypeptide chain only

Question 58

The first part of a new polypeptide chain being produced in a eukaryotic cell has a signal peptide. Translation of this polypeptide ____.

A) occurs on a free ribosome in the cytosol
B) begins on a free ribosome in the cytosol and is completed on the rough ER
C) occurs in the Golgi apparatus
D) begins on the rough ER and is completed in the Golgi apparatus
E) occurs on the rough ER

Question 59

Energy for the three stages of translation is directly provided by ____.

A) sugars
B) ATP
C) GTP
D) dNTP
E) fats

Question 60

During translation, mRNA is read in the ____ direction and the polypeptide is assembled from the ____.

A) 5'->3'; N-terminal end to the C-terminal end
B) 5'->3'; C-terminal end to the N-terminal end
C) 3'->5'; N-terminal end to the C-terminal end
D) 3'->5'; C-terminal end to the N-terminal end
E) 5'->5'; N-terminal end to the C-terminal end

Question 61

Use the table above for questions 67-69.
Assume that an mRNA transcript is synthesized complementary to this DNA sequence:
3'-CTTACATGGCATCC-5'
See the provided genetic code table. If the start codon is considered the first codon, which amino acid is specified by the second codon?

A) asparagine
B) tyrosine
C) arginine
D) proline
E) cysteine

Question 62

Which process occurs in the cytoplasm of a eukaryotic cell?

A) translation
B) DNA replication and transcription
C) transcription
D) DNA replication
E) translation and transcription

Question 63

Segments of DNA that can move from one place to another within a cell's genome are called ____.

A) target sites
B) transposases
C) transposable elements
D) replicative factors
E) release factors

Question 67

Use the table above for questions 67-69.
See the provided genetic code table. A change in a single base pair could cause which missense mutation?

A) glutamic acid to threonine
B) glycine to proline
C) threonine to glutamine
D) glutamic acid to methionine
E) valine to methionine

Question 68

Use the table above for questions 67-69.
See the provided genetic code table. The start codon for translation directs incorporation of which amino acid?

A) lysine
B) phenylalanine
C) methionine
D) glycine
E) no amino acid is encoded; the start codon simply begins the process

Question 70

Missense, nonsense, and silent mutations are all caused by single base changes in the coding region of a gene. How are these three types of mutations different?

Question 71

Describe the process of transcription in prokaryotes.

Question 72

Which proteins below are made only on free ribosomes in the cytosol?

A) glycolytic enzymes
B) digestive enzymes
C) microtubule proteins
D) cell surface receptors
E) both microtubules and glycolytic enzymes

Question 73

Mutagenesis ____.

A) is an example of spontaneous mutation
B) acts directly on proteins by causing them to unfold
C) occurs due to a single mRNA being translated by too many ribosomes simultaneously
D) is the production of mutations in a laboratory by exposure of a living organism to a mutagen
E) occurs when errors made by DNA polymerase are not repaired

Question 74

Using the genetic code shown here, predict the amino acid sequence that would be produced from the following partial DNA sequence if the top strand is the template strand:
3'-...TAC ACG TGG ACG TGA TTC TTA...-5'
5'-...ATG TGC ACC TGC ACT AAG AAT...-3'

Question 75

Explain how proteins that are produced in a cell are correctly directed to the cytosol, the endomembrane system, and the mitochondria.

Question 76

Proteins are sorted to mitochondria, chloroplasts, and the nucleus after they have been made on _________.  This sorting mechanism is called ___________.

A) ribosomes bound to the endoplasmic reticulum; posttranslational import
B) ribosomes bound to the endoplasmic reticulum; cotranslational import
C) ribosomes bound to the Golgi complex; posttranslational import
D) free ribosomes in the cytosol; posttranslational import
E) free ribosomes in the cytosol; cotranslational import

Question 77

A gene being transcribed uses transcription factors to recruit RNA polymerase II to the DNA at the promoter region. After the polymerase is recruited, transcription elongation occurs, and nucleotides are added to the transcript in the      5'->3' direction. How do you know that the gene being transcribed is not a prokaryotic gene?

A) In prokaryotes, the promoter comes after the transcription unit.
B) Prokaryotes do not have promoters.
C) In prokaryotes, nucleotides are added to the transcript in the 3'->5' direction.
D) Prokaryotes use ribosomes rather than RNA polymerase to transcribe genes.
E) In prokaryotes, RNA polymerase binds directly to DNA at the promoter without transcription factors.

Question 78

Briefly describe the positions of tRNA in the ribosome and relate them to the process of translation elongation.

Question 79

Noller's research with ribosomes showed that the site of peptide bond formation is located on ____.

A) the tRNA molecules
B) ribosomal DNA
C) proteins of the small ribosomal subunit
D) ribosomal RNA
E) proteins of the large ribosomal subunit

Question 80

Describe the process of mRNA splicing.