BIO 99 FINAL (QUIZZES) QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2026
The CRISPR/Cas system used in labs to modify many different organisms includes (select all that
apply): - Answers -an sgRNA molecule
-the nuclease domain of Cas9
What is the relationship between miR17-92 and tumor formation? - Answers miR17-92
overexpression leads to tumor formation.
What is the main difference between siRNA and miRNA? - Answers miRNAs are encoded by the
genome; siRNAs are not.
Which of the following is not true of miRNA processing? - Answers Dicer completes the processing by
cleaving the single-stranded form of the miRNA.
Mature siRNA annealed to its target usually leads to translational repression when: - Answers the
siRNA is only partially complementary to the target RNA.
Which one of the following is true of tRNA molecules? Select all that apply. - Answers -tRNA
molecules contain the unusual nucleotides dihydrouridine, pseudouridine, and ribothymine
-The 3' terminal nucleotide of tRNA is the site of amino acid attachment
-tRNA molecules are single stranded RNA.
How many codons of the genetic code are used for coding amino acids? - Answers None of the above
(61 codons)
The genetic code is degenerate because: - Answers one particular amino acid can be encoded by more
than one codon.
Which of the following statements is a feature of the wobble hypothesis? - Answers When inosine (I)
is the first nucleotide of an anticodon, up to three different codons can be recognized by that tRNA.
Because the genetic code is non-overlapping, a missense mutation (from a single nucleotide change)
results in the alteration of ___________, and the resulting protein has _____________. - Answers -1st
blank: only one codon
-2nd blank: at most, a single amino acid change
A frameshift of an entire coding region of an mRNA molecule is most likely to be caused by a: -
Answers Single nucleotide deletion.
Which of the following statements about the use of synthetic polynucleotides in cracking the genetic
code is true? - Answers -Poly(A) RNA directs the synthesis of only polylysine in vitro
-The codon table was completed by using RNA polymers of defined sequences
-Particular codons are generated in predictable ratios with random RNA polymers containing specific
ratios of different nucleotides
Which of the following best describes the procedure Nirenberg took to decipher the genetic code? -
Answers They added ribosomes, tRNA, and codons together to see which codons resulted in
tRNA/ribosome association.
Which of the following is true regarding the make-up of the ribosome? - Answers The RNA make up
more of the ribosome mass than the protein components.
Which one of the following experimental results does not support the hypothesis that the ribosome is
a ribozyme? - Answers Ribosomes from thermophilic organisms are more stable than from E. coli.
Which of the following best describes the tRNA binding sites of the ribosome? - Answers The P site
contains the tRNA molecule covalently bound to the growing chain of amino acids.
The changing or activation of a tRNA molecule includes: - Answers the covalent attachment of the
carboxyl group of an amino acid to the tRNA.
A difference between a Class I and a Class II tRNA synthetase is (select all that apply): - Answers -the
Class I synthetase uses the 2' OH of the 3' end of the tRNA as a nucleophile and the Class II uses the 3'
OH.
-the Class I synthetase reaction requires a transesterification reaction not necessary in the Class II
reaction.
What result allowed Dintzis to conclude that proteins are synthesized from the N terminus to C
terminus? - Answers The more newly synthesized peptides had greater levels of radiolabeled H.
The Shine-Dalgarno mRNA sequence is: - Answers the ribosomal binding site on the mRNA.
Which of the following statements explains how N-formylmethionine (fMet) is only associated with
the 5' AUG initiation codon and not with internal AUG codons, given that methionine in both cases in
encoded by an AUG in the mRNA. Select all that apply. - Answers -Only fMet-tRNA(fMet) can bind first
to the P site in the ribosome.
The CRISPR/Cas system used in labs to modify many different organisms includes (select all that
apply): - Answers -an sgRNA molecule
-the nuclease domain of Cas9
What is the relationship between miR17-92 and tumor formation? - Answers miR17-92
overexpression leads to tumor formation.
What is the main difference between siRNA and miRNA? - Answers miRNAs are encoded by the
genome; siRNAs are not.
Which of the following is not true of miRNA processing? - Answers Dicer completes the processing by
cleaving the single-stranded form of the miRNA.
Mature siRNA annealed to its target usually leads to translational repression when: - Answers the
siRNA is only partially complementary to the target RNA.
Which one of the following is true of tRNA molecules? Select all that apply. - Answers -tRNA
molecules contain the unusual nucleotides dihydrouridine, pseudouridine, and ribothymine
-The 3' terminal nucleotide of tRNA is the site of amino acid attachment
-tRNA molecules are single stranded RNA.
How many codons of the genetic code are used for coding amino acids? - Answers None of the above
(61 codons)
The genetic code is degenerate because: - Answers one particular amino acid can be encoded by more
than one codon.
Which of the following statements is a feature of the wobble hypothesis? - Answers When inosine (I)
is the first nucleotide of an anticodon, up to three different codons can be recognized by that tRNA.
Because the genetic code is non-overlapping, a missense mutation (from a single nucleotide change)
results in the alteration of ___________, and the resulting protein has _____________. - Answers -1st
blank: only one codon
-2nd blank: at most, a single amino acid change
A frameshift of an entire coding region of an mRNA molecule is most likely to be caused by a: -
Answers Single nucleotide deletion.
Which of the following statements about the use of synthetic polynucleotides in cracking the genetic
code is true? - Answers -Poly(A) RNA directs the synthesis of only polylysine in vitro
-The codon table was completed by using RNA polymers of defined sequences
-Particular codons are generated in predictable ratios with random RNA polymers containing specific
ratios of different nucleotides
Which of the following best describes the procedure Nirenberg took to decipher the genetic code? -
Answers They added ribosomes, tRNA, and codons together to see which codons resulted in
tRNA/ribosome association.
Which of the following is true regarding the make-up of the ribosome? - Answers The RNA make up
more of the ribosome mass than the protein components.
Which one of the following experimental results does not support the hypothesis that the ribosome is
a ribozyme? - Answers Ribosomes from thermophilic organisms are more stable than from E. coli.
Which of the following best describes the tRNA binding sites of the ribosome? - Answers The P site
contains the tRNA molecule covalently bound to the growing chain of amino acids.
The changing or activation of a tRNA molecule includes: - Answers the covalent attachment of the
carboxyl group of an amino acid to the tRNA.
A difference between a Class I and a Class II tRNA synthetase is (select all that apply): - Answers -the
Class I synthetase uses the 2' OH of the 3' end of the tRNA as a nucleophile and the Class II uses the 3'
OH.
-the Class I synthetase reaction requires a transesterification reaction not necessary in the Class II
reaction.
What result allowed Dintzis to conclude that proteins are synthesized from the N terminus to C
terminus? - Answers The more newly synthesized peptides had greater levels of radiolabeled H.
The Shine-Dalgarno mRNA sequence is: - Answers the ribosomal binding site on the mRNA.
Which of the following statements explains how N-formylmethionine (fMet) is only associated with
the 5' AUG initiation codon and not with internal AUG codons, given that methionine in both cases in
encoded by an AUG in the mRNA. Select all that apply. - Answers -Only fMet-tRNA(fMet) can bind first
to the P site in the ribosome.
