Deck 26: Gene Expression and Protein Synthesis

Question 1

Which of the following is true?

A) There is a single promoter for all genes.
B) There are a few promoters, but each is a promoter for many genes.
C) There are many promoters and each is a promoter for a few genes.
D) Each gene has a unique promoter.

Answer 1

D

Question 2

Which of the following has a sequence that matches that of the RNA being produced?

A) the DNA antisense strand
B) the DNA (−) strand
C) the DNA sense strand
D) the DNA template strand

Answer 2

C

Question 3

The TATA box is an example of which of the following?

A) a consensus initiation signal
B) a promoter
C) a termination sequence
D) a transcription factor

Answer 3

A

Question 4

In eukaryotes which of the following is true?

A) Transcription never occurs in the nucleus.
B) Translation always occurs in the nucleus.
C) Translation sometimes occurs in the nucleus.
D) Translation never occurs in the nucleus.

Question 5

A sequence of how many bases is needed to code for an amino acid?

A) 1
B) 2
C) 3
D) 4

Question 6

Which of the following occurs in retroviruses?

A) DNA is replicated in the 3' → 5' direction
B) DNA is replicated in the 5' → 3' direction
C) DNA is transcribed to RNA
D) RNA is transcribed to DNA

Question 7

Which of the following has a sequence that serves as a template for the RNA being produced?

A) the DNA coding strand
B) the DNA (−) strand
C) the DNA (+ ) strand
D) the DNA sense strand

Question 8

Which portion of a eukaryotic gene carries information which will be transcribed to the RNA?

A) the entire gene
B) the promoter
C) the regulatory portion
D) the structural gene

Question 9

Which of the following is true?

A) We know more about transcription and translation in eukaryotes than about these processes in prokaryotes.
B) We know more about transcription and translation in prokaryotes than about these processes in eukaryotes.
C) We know the same amount about transcription and translation in prokaryotes eukaryotes.
D) The processes of transcription and translation are identical in eukaryotes and prokaryote.

Question 10

In eukaryotes which of the following is true?

A) Transcription always occurs in the nucleus.
B) Transcription never occurs in the nucleus.
C) Translation always occurs in the nucleus.
D) Translation never occurs in the nucleus.

Question 11

Which of the following is true during transcription?

A) Both strands of DNA serve as a template for RNA.
B) Only the antisense strand of DNA serves as a template for RNA.
C) Only the sense strand of DNA serves as a template for RNA.
D) Transcription involves merging information from both strands of DNA.

Question 12

Where in the gene is the promoter located?

A) in the exons
B) in the introns
C) in the regulatory portion
D) It can be in any of these.

Question 13

Which of the following is involved in making the DNA less dense and more accessible?

A) acetylase
B) helicase
C) binding proteins
D) polymerases

Question 14

HIV, the retrovirus which causes AIDS, does which of the following?

A) uses reverse transcriptase to synthesize DNA
B) uses RNA replicase replicate it own RNA
C) both a and b
D) neither a nor b

Question 15

RNA polymerase I (pol I) catalyzes the formation of which type of RNA?

A) mRNA
B) rRNA
C) snRNA
D) tRNA

Question 16

Which base will be added to the growing mRNA if the base on the DNA template is adenine?

A) cytosine
B) guanine
C) thymine
D) uracil

Question 17

Which of the following is involved in unwinding the DNA double helix?

A) acetylase
B) helicase
C) binding proteins
D) polymerases

Question 18

RNA polymerase II (pol II) catalyzes the formation of which type of RNA?

A) mRNA
B) rRNA
C) snRNA
D) tRNA

Question 19

Which of the following is the consensus base sequence of a TATA box?

A) TATA
B) TATATA
C) TATAAT
D) TTAATTAA

Question 20

In eukaryotes how many polymerases catalyze transcription?

A) 1
B) 2
C) 3
D) 4

Question 21

Which of the following is true at the time introns are spliced out of mRNA?

A) Neither end of the mRNA has been processed.
B) Both ends of the mRNA have been processed.
C) Only the 3' end of mRNA has been processed.
D) Only the 5' end of the mRNA is has been processed.

Question 22

Which polymerases interact with their promoters via transcription factors?

A) pol I
B) pol II
C) pol III
D) all of these

Question 23

Pol II has how many different forms (conformations)?

A) 1
B) 2
C) 3
D) 4

Question 24

Which of the following must occur to insure that mRNA is functional?

A) Nothing, the newly synthesized mRNA is always already functional.
B) The mRNA must be processed at the 3' end.
C) The mRNA must be processed on the 5' end.
D) The mRNA must be processed at both ends.

Question 25

How does mRNA bind to the ribosomal units?

A) It doesn't bind to either ribosomal unit.
B) It binds to the smaller unit first and then to the larger unit.
C) It binds to the larger unit first and then to the smaller unit.
D) It binds to both units simultaneously.

Question 26

tRNA has a shape similar to which letter of the alphabet?

A) C
B) L
C) S
D) T

Question 27

Which of the following is true of enhancers?

A) They are always located next to the TATA box.
B) They are always part of the promoter.
C) They are always located far from the promoter.
D) They may be located far from the promoter.

Question 28

What is the relationship between the bases of the codon on mRNA and the anticodon on tRNA?

A) They have complementary base sequences.
B) They have identical base sequences.
C) They have similar base sequences.
D) They have palindromic base sequences.

Question 29

Which amino acids are found at the C-terminal domain of pol II?

A) alanine and serine
B) alanine and glycine
C) glycine and threonine
D) serine and threonine

Question 30

What is the name given to a sequence of three bases on mRNA?

A) anticodon
B) codon
C) recognition site
D) synthesis site

Question 31

How is an amino acid transported by tRNA?

A) It is bound to the 3' end.
B) It is bound to the 5' end.
C) It is bound to either the 3' or the 5' end.
D) It is enveloped by the tRNA.

Question 32

What are the sizes of the ribosomal units in prokaryotes?

A) 30S and 50S
B) 30S and 60S
C) 40S and 60S
D) 40S and 50S

Question 33

Which of the following is true?

A) mRNA is synthesized in the 3' → 5' direction and the polymerase moves along the DNA template in the 3' → 5' direction.
B) mRNA is synthesized in the 5' → 3' direction and the polymerase moves along DNA template in the 5' → 3' direction.
C) mRNA is synthesized in the 3' → 5' direction but the polymerase moves along the DNA template in the 5' → 3'direction.
D) mRNA is synthesized in the 5' → 3' direction but the polymerase moves along the DNA template in the 3' → 5' direction.

Question 34

Which of the following is the correct name for the enzymes which bind an amino acid to its matching tRNA?

A) acyl-tRNA synthetases
B) aminyl-tRNA synthetases
C) aminoacyl-tRNA synthetases
D) aminoacetyl-tRNA synthetases

Question 35

The size of ribosomal subunits is given in "S" units. "S" stands for which of the following?

A) selectivity
B) size
C) Svedberg units
D) synthesizing ability

Question 36

Where on the tRNA molecule is the anticodon located?

A) at the 3' end
B) at the 5' end
C) in a loop in the molecule which is physically far from the 3' end
D) in a loop in the molecule which is physically near to the 3' end

Question 37

Which of the following scientists is most closely associated with deciphering the genetic code?

A) O. Avery
B) E. Chargaff
C) M. Nirenberg
D) J. Watson

Question 38

Which of the following is true of pol II?

A) It must be in its phosphorylated form to cause both the initiation and elongation.
B) It must be in its dephosphorylated form to cause both the initiation and elongation.
C) It must be in its phosphorylated form to initiate transcription but must be in its dephosphorylated form to cause elongation.
D) It must be in its dephosphorylated form to initiate transcription but must be in its phosphorylated form to cause elongation.

Question 39

What happens to the mRNA when it binds to the two ribosomal bodies?

A) Nothing, it retains its original three-dimensional shape.
B) It forms a double helix.
C) It is stretched out.
D) It splits into two parts, each of which is associated with a ribosomal unit.

Question 40

During elongation what kind of bond is formed as the RNA is synthesized?

A) a diphosphate
B) a phosphate ester
C) phosphate ether
D) none of these

Question 41

Which of the following is true of methionine?

A) It is the C-terminus of all active proteins.
B) It is the N-terminus of all active proteins.
C) During protein synthesis it is always the C-terminus.
D) During protein synthesis it is always the N-terminus.

Question 42

How many initiation codons are there?

A) 1
B) 3
C) 4
D) 20

Question 43

How many different codons are there?

A) 3
B) 20
C) 64
D) 256

Question 44

What type of bond is formed when an amino acid binds to its tRNA?

A) an amide bond
B) an ester bond
C) an ionic bond
D) The type of bond depends on the specific amino acid.

Question 45

The term "second genetic code" refers to which of the following?

A) The ability of the codon and anticodon to recognize each other.
B) The ability of aminoacyl-tRNA synthetases to correctly pair an amino acid with its correct tRNA.
C) The ability of DNA to transfer genetic information to RNA.
D) None of these is correct.

Question 46

Which amino acids are coded for by the most codons?

A) glycine and alanine
B) glycine and leucine
C) leucine and serine
D) leucine and methionine

Question 47

Which of the following is true?

A) Every organism has its own genetic code.
B) All prokaryotes have a common genetic code, but each eukaryotic organism has its own genetic code.
C) All prokaryotes have a common genetic code and all eukaryotes have a common genetic code, but these codes are different.
D) The genetic code is virtually universal, and is shared by all organisms.

Question 48

Which amino acid other than methionine is coded for by only a single codon?

A) glycine
B) phenylalanine
C) proline
D) tryptophan

Question 49

Which of the following is true if an amino acid is incorrectly paired with a tRNA?

A) This is not important since the complex will be very unstable.
B) This is not important since the anticodon will not match up with its codon.
C) This is not important since the incorrectly placed amino acid can be removed later.
D) This can be a serious problem since the anticodon will match up with its codon even if the tRNA is carrying the wrong amino acid.

Question 50

During protein synthesis how is the code on mRNA read?

A) in the 3' → 5'direction
B) in the 5' → 3' direction
C) Starting from the methionine codon it is read in both directions.
D) Starting from the middle codon it is read in both directions.

Question 51

How many codons, including redundant codons, would there be if proteins involved 100 different amino acids rather than 20?

A) 4
B) 128
C) 256
D) 512

Question 52

How many stop codons are there?

A) 1
B) 3
C) 4
D) 20

Question 53

How does a specific aminoacyl-tRNA synthetase recognize its tRNA?

A) by the anticodon loop of tRNA
B) by the residue at the 3' end of the tRNA
C) by the residue at the 5' end of the tRNA
D) By a nucleotide sequence on the tRNA which may or may not include the anticodon loop.

Question 54

One of the codons for threonine is 5'ACG3'. What is the anticodon for this codon?

A) 5'GCA3'
B) 5'ACG3'
C) 5'CGT3'
D) 5'CGU3'

Question 55

Which of the following is suggestive that mitochondria may have been an ancient entity?

A) Mitochondria produce energy
B) Some exceptions to the genetic code are found in mitochondrial DNA.
C) Mitochondrial DNA is passed only through the female line.
D) None of the above is correct.

Question 56

One of the codons for histidine is 5'CAU3'. What is the anticodon for this codon?

A) 5'UAC3'
B) 5'AUG3'
C) 5'AUG3'
D) 5'CAU3'

Question 57

Which position of a codon is generally the least important in determining which amino acid the codon codes for?

A) the first
B) the second
C) the third
D) None of them, they are all equally important.

Question 58

The genetic code is associated with which of the following processes?

A) DNA replication
B) translation
C) transcription
D) all of these

Question 59

Which of the following is true?

A) There is a single aminoacyl-tRNA synthetase.
B) There are four different aminoacyl-tRNA synthetases, one for each different type of amino acid side chain.
C) A different aminoacyl-tRNA synthetase is required for each amino acid.
D) None of the above is correct.

Question 60

Where on the tRNA does the amino acid bind?

A) at the 3' end
B) at the 5' end
C) at the anticodon loop
D) at a methionine residue

Question 61

Which of the following is carried by tRNA^fMet during the formation of the pre-initiation complex?

A) flavinmethionine
B) fluoromethionine
C) formylmethionine
D) fullermethionine

Question 62

Which of the following is involved in the termination of protein synthesis?

A) ATP
B) CTP
C) GTP
D) TTP

Question 63

Which of the following is not involved in regulating control at the transcriptional level?

A) enhancers
B) promoters
C) response elements
D) tRNAs

Question 64

Which of the following enzymes is involved in adding the new amino acid to the growing protein?

A) amididase
B) peptidyl synthetase
C) peptidyl transferase
D) ribosomal synthetase

Question 65

How many sites are associated with the full ribosomal complex?

A) 1
B) 2
C) 3
D) 4

Question 66

How many transcription factors are required for the initiation of transcription?

A) 1
B) 2
C) 4
D) 6

Question 67

Which of the following is involved in the formation of the pre-initiation complex?

A) ATP
B) CTP
C) GTP
D) UTP

Question 68

As a protein is synthesized the amino acid to be added is brought by its aminoacyl-tRNA to which of the following?

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

Question 69

Which of the following is the mechanism of peptide bond formation during protein synthesis?

A) Nucleophilic attack on the carbon of a carbonyl group by an amino group.
B) Nucleophilic attack on the nitrogen of an amino group by the carbon of a carbonyl group.
C) Nucleophilic attack on the nitrogen of an amino group by the oxygen of a carbonyl group.
D) Nucleophilic attack on the oxygen of a carbonyl group by an amino group.

Question 70

Which of the following is involved in ensuring that the small ribosomal unit is properly aligned on the mRNA

A) the anticodon
B) the codon
C) the Shine-Dalgarno sequence
D) the Svedberg sequence

Question 71

Which of the following is not one of the 20 standard amino acids which are the building blocks of proteins, but is in fact sometimes found in proteins?

A) citrulline
B) ornithine
C) selenocysteine
D) xanadine

Question 72

How many fundamental types of transcription factors are there?

A) 1
B) 2
C) 4
D) 6

Question 73

Which of the following must occur so that the pre-initiation complex can be converted to the open complex?

A) The C terminal end of the RNA polymerase must be dephosphorylated.
B) The C terminal end of the RNA polymerase must be phosphorylated.
C) The N terminal end of the RNA polymerase must be dephosphorylated.
D) The N terminal end of the RNA polymerase must be phosphorylated.

Question 74

When gene regulation occurs at the transcriptional level where are the control sites for gene regulation?

A) at the 3' end of the transcribed mRNA
B) at the 5' end of the transcribed mRNA
C) in front of the 3' end the structural gene
D) in front of the 5' end of the structural gene

Question 75

What is the size of the full prokaryotic ribosomal complex?

A) 30S
B) 50S
C) 70S
D) 80S

Question 76

Which of the following catalyzes peptide bond formation during protein synthesis?

A) a purine of the ribosomal RNA
B) a pyrimidine of the ribosomal RNA
C) a specialized protein found in the ribosome
D) all of the above

Question 77

How many general transcription factors are there?

A) 1
B) 2
C) 4
D) 6

Question 78

During elongation how many of the general transcription factors are totally released?

A) 0
B) 2
C) 3
D) 6

Question 79

After an amino acid has formed a peptide bond, where is its tRNA translocated to?

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

Question 80

To which of the following does the pre-initiation complex migrate during protein synthesis?

A) the entire ribosome
B) the larger ribosomal subunit
C) small ribosomal subunit
D) the mRNA