Deck 16: How Genes Work

Question 1

Which of the following is NOT synthesized from a DNA template?

A) messenger RNA
B) amino acids
C) transfer RNA
D) ribosomal RNA

Answer 1

B

Question 2

According to the central dogma, what molecule should go in the blank?
DNA → ________ → Proteins

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

Answer 2

C

Question 3

In the process of transcription, ________.

A) DNA is replicated
B) RNA is synthesized
C) proteins are synthesized
D) mRNA attaches to ribosomes

Answer 3

B

Question 4

Refer to the associated figure. A branched metabolic pathway synthesizes two related amino acids (D and

A) supplement intermediate B
B) supplement intermediate C
C) add enzyme 2 to the medium
D) supplement with intermediate E
F)) If there is a genetic defect, resulting in a nonfunctional enzyme (3), how could you ensure that adequate amounts of the amino acid F are synthesized?

Question 5

The statement "DNA → RNA → Proteins" ________.

A) is known as the central dogma
B) depicts the regulation of gene expression
C) is the same in all organisms, as well as viruses and prions
D) describes a series of catalytic reactions

Question 6

All three domains (Bacteria, Archaea, and Eukarya) follow the same genetic code. Therefore, which of the following statements would most likely be correct?

A) The genetic code evolved three times.
B) The genetic code evolved before DNA replaced RNA as the unit of genetic information.
C) There were no mutations following the evolution of the genetic code.
D) The genetic code evolved before the different domains diverged.

Question 7

Knockout mice have been genetically altered to knock out specific genes. How are these mice most often used in research?

A) to study DNA replication in the defective genes (those that have been altered)
B) to determine the role of proteins coded for by those genes that are knocked out
C) to examine defects in DNA structure in those regions that have been altered
D) to study the effect of radiation on DNA

Question 8

Beadle and Tatum discovered that metabolic pathways are studied most effectively using which of the following techniques?

A) using multiple gene mutations resulting in nonfunctional enzymes specific to a metabolic pathway
B) adding intermediates to a metabolic pathway
C) removing all intermediates of a metabolic pathway
D) using single gene mutations resulting in nonfunctional enzymes specific to a metabolic pathway

Question 9

Genotype is to ________ as phenotype is to ________.

A) DNA base sequence; physical traits that are products of the proteins produced
B) heredity; DNA base sequence
C) gene regulation; translation
D) transcription; amino acid sequence

Question 10

Given the DNA template shown in the associated figure, which of the following bases would you find in a complementary RNA strand and where would they be synthesized?

A) A-A-A-A-A; nucleus
B) U-U-U-U-U; nucleus
C) A-A-A-A-A; ribosome
D) U-U-U-U-U; ribosome

Question 11

In the Morse code, a series of dots and dashes code for letters of the alphabet. How is this analogous to the genetic code?

A) There is complementarity in the genetic code (A is complementary to T, and C is complementary to
B) The bases that make up DNA are coded by the sugar-phosphate backbone.
C) The machinery involved in DNA synthesis is analogous to the telegraph equipment used in sending Morse code.
D) The bases of DNA code for the more complex amino acid sequence of the proteins in cells.
G))

Question 12

Once researchers identified DNA as the unit of inheritance, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. What is the mechanism of information transfer in eukaryotes?

A) DNA from a single gene is replicated and transferred to the cytoplasm, where it serves as a template for protein synthesis.
B) Messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place.
C) Proteins transfer information from the nucleus to the ribosome, where protein synthesis takes place.
D) Transfer RNA takes information from DNA directly to a ribosome, where protein synthesis takes place.

Question 13

In the first step of their experiments, Jacob and Monod treated E. coli cells with ultraviolet light or X-rays to ________.

A) decrease the rate of gene expression
B) induce DNA repair enzymes
C) increase the frequency of mutations in all genes
D) selectively mutate specific genes, leaving all other genes unmutated

Question 14

Which of the following contradicts the one-gene, one-enzyme hypothesis?

A) A mutation in a single gene can result in a defective protein.
B) Alkaptonuria results when individuals lack a single enzyme involved in the catalysis of homogentisic acid.
C) Sickle cell anemia results in defective hemoglobin.
D) A single antibody gene can code for different related proteins, depending on the splicing that takes place post-transcriptionally.

Question 15

According to the table and the figure associated with this question, which enzyme is defective in the strain with the arg2 mutation?

A) the enzyme that converts the precursor to ornithine
B) the enzyme that converts ornithine to citrulline
C) the enzyme that converts citrulline to arginine
D) the enzyme that converts the precursor to citrulline

Question 16

Refer to the associated figure. In the branched metabolic pathway indicated in the figure, if enzyme 3 is defective and the amount of each enzyme is constant, you might expect to see an increase in the amount of which intermediate or product?

A) E
B) B
C) F
D) D

Question 17

HIV, the causative agent of AIDS, is a retrovirus. A retrovirus ________.

A) uses DNA as a template in the process of translation
B) makes proteins directly from RNA
C) uses reverse transcriptase to make DNA from RNA
D) is a cellular virus that uses ribosomes to reproduce inside a living cell

Question 18

Refer to the metabolic pathway illustrated in the associated figure. If A, B, and C are all required for growth, a strain mutant for the gene encoding enzyme B would be able to grow on medium supplemented with ________.

A) nutrient A only
B) nutrient B only
C) nutrient C only
D) nutrients A and C

Question 19

The proteome is all the proteins produced by an organism. The genome is the totality of all genes of an organism. If the proteome is much larger than the genome, which of the following statements would be accurate?

A) This finding lends support to a one-gene, two-enzyme hypothesis.
B) The number of monomeric subunits found in proteins is fewer than the number of monomeric subunits found in genes.
C) At least in some cases, a single gene must code for more than one protein.
D) Noncoding DNA is important in determining the proteome.

Question 20

Which of the following is an exception to the central dogma?

A) the discovery of RNA viruses that synthesize DNA using reverse transcriptase
B) the discovery that the Archaea and Bacteria are more distantly related than are Archaea and Eukarya
C) the discovery of ribozymes
D) the discovery of DNA as the unit of genetic inheritance

Question 21

How does the simple primary and secondary structure of DNA hold the information needed to code for the many features of multicellular organisms?

A) The hydrogen bonding among backbone constituents carries coded information.
B) The base sequence of DNA carries the information needed to code for proteins.
C) The width of the double helix changes at each gene due to differences in hydrogen bonds.
D) The amino acids that make up the DNA molecule contain the information needed to make cellular proteins.

Question 22

Which one of the following is TRUE? A codon ________.

A) consists of four nucleotides
B) can code for up to four different amino acids
C) extends from one end of a tRNA molecule
D) is the basic unit of the genetic code

Question 23

The mutation resulting in sickle cell disease changes one base pair of DNA so that a codon now codes for a different amino acid, making it an example of a ________.

A) nonsense mutation
B) frameshift mutation
C) silent mutation
D) missense mutation

Question 24

The following question(s) refer to this table of codons.
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'

Question 25

Use this representation to answer the following question.
DNA template strand 5' ________ 3'
DNA nontemplate strand 3' ________ 5'
Given the locally unwound double strand above, in which direction does the RNA polymerase move while transcribing DNA?

A) 3' → 5' along the template DNA strand
B) 5' → 3' along the template DNA strand
C) 3' → 5' along the nontemplate DNA strand
D) 5' → 3' along the nontemplate DNA strand
E) 5' → 3' along the double-stranded DNA

Question 26

Which of the following is directly related to a single amino acid?

A) the base sequence of the tRNA
B) the type of RNA polymerase used to carry out transcription
C) the three-base sequence of mRNA
D) the complementarity of DNA and RNA

Question 27

The following question(s) refer to this table of codons.
What amino acid sequence will be generated, 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

Question 28

Codons are part of the molecular structure of ________.

A) a protein
B) mRNA
C) tRNA
D) rRNA

Question 29

Consider the following section of mRNA:
UCUGAUGGGCUUU…
Beginning with the start codon, which amino acids, in order, are coded for by this section of mRNA? Consult the codon table provided if necessary.

A) serine, aspartic acid, glycine, leucine
B) methionine, glycine, phenylalanine
C) methionine, valine, glycine, phenylalanine
D) threonine, methionine, glycine

Question 30

Which of the following nucleotide triplets best represents a codon?

A) a triplet separated spatially from other triplets
B) a triplet in the middle of a ribosomal RNA molecule
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

Question 31

Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?

A) a deletion of a codon
B) a deletion of two nucleotides
C) a substitution of the third nucleotide in an ACC codon
D) a substitution of the first nucleotide of a GGG codon
E) an insertion of a codon

Question 32

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' UGS 5'
C) 5' TCA 3'
D) 3' ACU 5'
E) either UCA or TCA, depending on wobble in the first base

Question 33

A mutation that results in premature termination of translation ________.

A) is a silent mutation
B) is a nonsense mutation
C) usually has no effect on the function of the protein
D) is a missense mutation

Question 34

The following question(s) refer to this table of codons.
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

Question 35

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?

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 different amino acids.
E) Different organisms have different types of amino acids.

Question 36

Why might a point mutation in DNA make a difference in the level of a protein's activity?

A) It might result in a chromosomal translocation.
B) It might exchange one stop codon for another stop codon.
C) It might delay the rate of DNA replication.
D) It might substitute a different amino acid in the active site.
E) It might substitute the N-terminus of the polypeptide for the C-terminus.

Question 37

Which of the following observations may have resulted in the hypothesis that a codon is made up of three bases?

A) A codon of two bases in length, from four different bases, would code for a maximum of thirty-two different amino acids.
B) A codon of three bases in length, from four different bases, would code for a maximum of twelve different amino acids.
C) A codon of four bases in length, from four different bases, would code for a maximum of twenty-four different amino acids.
D) A codon of three bases in length, from four different bases, would code for a maximum of sixty-four different amino acids.

Question 38

What does it mean when we say the genetic code is redundant?

A) A single codon can specify the addition of more than one amino acid.
B) The genetic code is different for different domains of organisms.
C) The genetic code is universal (the same for all organisms).
D) More than one codon can specify the addition of the same amino acid.

Question 39

Point mutations are referred to as missense, silent, frameshift, or nonsense when they change the protein-coding potential of a gene. What is another group of mutations that may have important consequences for gene expression?

A) mutations that exist outside coding sequences
B) combinations of missense and silent mutations
C) combinations of nonsense and silent mutations
D) mutations that alter the amino acid sequence of a gene
E) mutations that shift the reading frame of a gene

Question 40

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) in a different organism
B) if one stop codon, such as UGA, is found to have a different effect on translation than 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
E) if a single mRNA molecule is found to translate to more than one polypeptide when there are two or more AUG sites

Question 41

Which of the following mutations is likely to cause the most dramatic phenotypic change?

A) a duplication of all or most introns
B) a large inversion whose ends are each in the same region between genes
C) a nucleotide substitution in an exon coding for a transmembrane domain
D) a single nucleotide deletion in an exon coding for an active site
E) a frameshift mutation one codon away from the 3' end of the nontemplate strand

Question 42

Which of the following DNA mutations is most likely to damage the protein it specifies?

A) a base-pair deletion
B) an addition of three nucleotides
C) a substitution in the last base of a codon
D) a codon deletion

Question 43

A nonsense mutation in a gene ________.

A) changes an amino acid in the encoded protein
B) has no effect on the amino acid sequence of the encoded protein
C) introduces a premature stop codon into the mRNA
D) alters the reading frame of the mRNA
E) prevents introns from being excised

Question 44

The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. This results in ________.

A) a base-pair substitution
B) a nucleotide mismatch
C) a frameshift mutation
D) a polypeptide missing an amino acid
E) a nonsense mutation

Question 45

A frameshift mutation could result from ________.

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

Question 46

Which small-scale mutation would be most likely to have a catastrophic 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

Question 47

Which of the following mutations would be most likely to have a harmful effect on an organism?

A) a nucleotide-pair substitution
B) a deletion of three nucleotides near the middle of a gene
C) a single nucleotide deletion in the middle of an intron
D) a single nucleotide deletion near the end of the coding sequence
E) a single nucleotide insertion downstream of, and close to, the start of the coding sequence

Question 48

The associated figure shows a diagram of blocks of genes on human chromosome 16 and the locations of blocks of similar genes on four chromosomes of the mouse.
The movement of these blocks suggests that ________.

A) during evolutionary time, these sequences have separated and have returned to their original positions
B) DNA sequences within these blocks have become increasingly divergent
C) sequences represented have duplicated at least three times
D) chromosomal translocations have moved blocks of sequences to other chromosomes
E) higher mammals have more convergence of gene sequences related in function