51 notecards = 13 pages (4 cards per page)
1) Garrod hypothesized that "inborn errors of metabolism"
such as alkaptonuria occur because _____.
B) enzymes are made of DNA, and affected individuals lack DNA
2) A particular triplet of bases in the template strand of DNA is 5'
AGT 3'. The corresponding codon for the mRNA transcribed is
C) 3' TCA 5'
3) The genetic code is essentially the same for all organisms. From
this, one can logically assume which of the following?
C) The same codons in different organisms translate into different amino acids.
D) Different organisms have different types of amino acids.
4) The figure above shows a simple metabolic pathway. According to
Beadle and Tatum's hypothesis, how many genes are necessary for this
5) Refer to the metabolic pathway illustrated above. If A, B, and C
are all required for growth, a strain that is mutant for the
gene-encoding enzyme A would be able to grow on medium supplemented
B) nutrient B only
C) nutrient C only
D) nutrients A and C
6) Refer to the metabolic pathway illustrated above. 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
B) nutrient B only
C) nutrient C only
D) nutrients A and C
10) Which of the following contradicts the one-gene, one-enzyme
11) Which of the following is directly related to a single amino acid?
A) the base sequence of the tRNA
D) the complementarity of DNA and RNA
12) In the process of transcription, _____.
A) DNA is replicated
D) mRNA attaches to ribosomes
13) Codons are part of the molecular structure of _____.
A) a protein
14) What does it mean when we say the genetic code is
B) The genetic code is different for different domains of
15) 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 eukarotes?
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.
D) Transfer RNA takes information from DNA directly to a ribosome, where protein synthesis takes place.
16) According to the central dogma, what molecule should go in the
blank? DNA → _____ → Proteins
17) Codons are three-base sequences that specify the addition of a
single amino acid. How do eukaryotic codons and prokaryotic codons
C) The translation of codons is mediated by tRNAs in eukaryotes, but
translation requires no intermediate molecules such as tRNAs in
18) Which of the following occurs in prokaryotes but not in eukaryotes?
A) post-transcriptional splicing
D) gene regulation
19) Which of the following statements best describes the termination
of transcription in prokaryotes?
20) In eukaryotes there are several different types of RNA
polymerase. Which type is involved in transcription of mRNA for a
C) RNA polymerase III
21) Transcription in eukaryotes requires which of the following in addition to RNA polymerase?
A) start and stop codons
D) aminoacyl-tRNA synthetase
22) Which of the following best describes the significance of the
TATA box in eukaryotic promoters?
C) It is the recognition site for ribosomal binding.
D) Its significance has not yet been determined.
23) Which of the following does not occur in prokaryotic gene
expression, but does occur in eukaryotic gene expression?
C) A cap is added to the 5' end of the mRNA.
24) A ribozyme is _____.
D) an enzyme that synthesizes RNA as part of the transcription process
25) Alternative RNA splicing _____.
C) can allow the production of similar proteins from different
26) 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
D) the number of start sites for transcription
27) In an experimental situation, a student researcher inserts an
mRNA molecule into a eukaryotic cell after she has removed its 5' cap
and poly-A tail. Which of the following would you expect her to
29) Which one of the following statements about RNA processing is true?
A) Exons are cut out before mRNA leaves the nucleus.
D) A primary transcript is often much shorter than the final RNA molecule that leaves the nucleus.
30) A primary transcript in the nucleus of a eukaryotic cell is _____
the functional mRNA, while a primary transcript in a prokaryotic cell
is _____ the functional mRNA.
C) larger than; smaller than
31) A particular triplet of bases in the coding sequence of DNA is
AAA. The anticodon on the tRNA that binds the mRNA codon is
32) Accuracy in the translation of mRNA into the primary structure of
a polypeptide depends on specificity in the _____.
C) attachment of amino acids to rRNAs
33) A mutant bacterial cell has a defective aminoacyl-tRNA synthetase
that attaches a lysine to tRNAs with the anticodon AAA instead of the
normal phenylalanine. The consequence of this for the cell will be
B) proteins in the cell will include lysine instead of phenylalanine
at amino acid positions specified by the codon UUU
D) the ribosome will skip a codon every time a UUU is encountered
34) There are sixty-one mRNA codons that specify an amino acid, but
only forty-five tRNAs. This is best explained by the fact that
C) many codons are never used, so the tRNAs that recognize them are dispensable D) the DNA codes for all sixty-one tRNAs, but some are then destroyed
35) Which of the following is the first event to take place in
translation in eukaryotes? A) base pairing of activated
methionine-tRNA to AUG of the messenger RNA
D) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA
36) A signal peptide _____.
B) terminates translation of messenger RNA
37) The release factor (RF) _____.
43) What must occur before a newly made polypeptide is secreted from
44) Translation requires _____.
45) During elongation, which site in the ribosome represents the
location where a codon is being read?
C) A site
46) Once a peptide has been formed between the amino acid attached to
the tRNA in the P site and the amino acid associated with the tRNA in
the A site, what occurs next?
47) Which one of the following, if missing, would usually prevent translation from starting?
D) poly-A tail
48) Put the following events of elongation in prokaryotic translation
in chronological order. 1. Binding of mRNA with small ribosomal
4. Base pairing of the mRNA codon following the initiator codon with
its complementary tRNA 5. Attachment of the large subunit
C) 5, 4, 3, 2, 1
49) How does termination of translation take place?
A) The end of the mRNA molecule is reached.
D) The poly-A tail is reached.
50) Post-translational modifications of proteins may include the _____.
A) removal of introns
D) addition of carbohydrates to form a glycoprotein
51) Which of the following statements is true about protein synthesis
B) Translation can begin while transcription is still in
52) 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
C) a substitution of the third nucleotide in an ACC codon
D) a substitution of the first nucleotide of a GGG codon
53) A nonsense mutation in a gene _____.
C) introduces a premature stop codon into the mRNA
54) Which of the following DNA mutations is most likely to damage the protein it specifies?
A) a base-pair deletion
D) a codon deletion
55) The most commonly occurring mutation in people with cystic
fibrosis is a deletion of a single codon. This results in _____.
C) a polypeptide missing an amino acid
D) a nonsense mutation
56) Of the following, which is the most current description of a
D) a discrete unit of hereditary information that consists of a sequence of amino acids
57) How might a single base substitution in the sequence of a gene
affect the amino acid sequence of a protein encoded by the gene, and
C) All amino acids following the substitution would be affected,
because the reading frame would be shifted.
58) An original section of DNA has the base sequence AGCGTTACCGT. A mutation in this DNA strand results in the base sequence AGGCGTTACCGT. This change represents _____.
A) a missense mutation
C) a silent mutation
59) A single base substitution mutation is least likely to be
deleterious when the base change results in _____.
C) an amino acid substitution that alters the tertiary structure of the protein
D) an amino acid substitution at the active site of an enzyme
60) Rank the following one-base point mutations (from most likely to
least likely) with respect to their likelihood of affecting the
structure of the corresponding polypeptide.
3. substitution mutation at the second position of an exonic codon
4. deletion mutation within the first exon of the gene
C) 2, 1, 4, 3