BIO 148 UK Osterhage Exam 2 Study
Guide Exam with All Correct Answers.
1. Many different types of protein molecules are made within cells. Which of the following could
be influenced by the actions of those protein molecules?
a. Both an organism's physical characteristics and the function of the organism's cells
b. An organism's physical characteristics but not the function of the organism's cells
c. The function of the organism's cells but not the organism's physical characteristics
d. Neither an organism's physical characteristics nor the function of the organism's cells -
Answer a. Both an organism's physical characteristics and the function of the organism's cells
Proteins have a variety of functions inside cells. The function of some proteins can be seen as an
observable, physical characteristic.
2. What happens to the intron sections of genes?
a. They are neither transcribed nor translated
b. They are transcribed and translated
c. They are transcribed but not translated
d. They are not transcribed but they are translated. - Answer c. They are transcribed but not
translated
They are removed from the primary transcript during splicing.
3. The DNA molecules in eye cells contain which of the following?
a. Genes that encode eye color and skin color, and switches that control both eye color and skin
color
b. Genes that encode eye color and skin color, and switches that control eye color only (not skin
color)
c. Genes and switches that encode eye color only (not skin color)
d. Genes that control eye and skin color, but not switches for either of these genes. - Answer
a. Genes that encode eye color and skin color, and switches that control both eye color and skin
color
Switches are DNA sequences. The DNA in every body cell is, for the most part, the same.
4. Which of the following is a part of a DNA molecule?
,a. Promoter
b. Switch
c. Gene
d. All of the above
e. A and C only - Answer d. All of the above
5. 5' caps and 3' poly(A) tails of eukaryotic mRNAs ______.
a. protect mRNA from degradation and enhance transcription
b. mark the beginning and end of introns, respectively
c. act as sites for the start and stop of translation, respectively
d. protect mRNA from degradation and enhance translation - Answer d. protect mRNA from
degradation and enhance translation
We didn't specifically talk about them enhancing translation (but they do). They definitely
protect the RNA from degradation. It wouldn't make sense for them to enhance transcription
because they are put on after transcription occurs.
6. Different cells in the same organism express different proteins in part because:
a. their genomes are different
b. they contain different gene switches
c. different gene switches are activated
d. they use different genetic codes
e. b and c only - Answer c. different gene switches are activated
All body cells from an organism have the same DNA. Since switches are part of the DNA, all cells
have the same switches. All organisms use the same genetic code, so d cannot be true.
The activation of switches by activator proteins helps explain why different cells from the same
organism express different proteins.
7. Which of the following is TRUE about translation in eukaryotes?
a. The first amino acid translated from all mRNAs is the same
b. Translation begins at the very 5' end of all mRNAs
c. Translation terminates (stops) after the polyA tail is translated into amino acids
d. Each nucleotide in an mRNA specifies one amino acid
e. There are 20 different codons in mRNA, corresponding to the 20 different amino acids -
Answer a. The first amino acid translated from all mRNAs is the same
, Since AUG is the only start codon, all newly synthesized polypeptides start with a Met amino
acid. B isn't true because translation starts at the start codon, not the very 5' end of the RNA. C
isn't true because translation stops at a stop codon. D isn't true because it's the combination of
three nucleotides that codes for one amino acid. D isn't true because there are 64 codons.
8. Which of the following about gene switches is TRUE?
a. They are proteins
b. RNA polymerase binds to them directly
c. They are located within the promoter
d. They regulate the number of times an RNA is translated
e. They can be bound by activator proteins to "turn on" transcription - Answer e. They can
be bound by activator proteins to "turn on" transcription
9. At what point in the central dogma does addition of the poly(A) tail occur?
a. Between the gene and synthesis of the primary transcript
b. Between synthesis of the primary transcript and formation of the mature mRNA
c. Between formation of the mature mRNA and synthesis of the polypeptide
d. Between synthesis of the polypeptide and formation of the finished protein - Answer b.
Between synthesis of the primary transcript and formation of the mature mRNA
Poly(A) tail addition is part of processing that prepares a primary transcript, converting it to a
mature mRNA
10. Which of the following would you expect to find in a mature mRNA?
a. Introns
b. Promoters
c. Codons
d. Amino acids
e. Switches - Answer c. Codons
Promoters and switches are not transcribed, so they can't be there. Introns aren't there either,
because they have been spliced out. Amino acids are part of proteins, not RNA.
Refer to the genetic code in this exam regarding the section of mRNA directly below.
5' UCUGAUGGGCUUU...
Guide Exam with All Correct Answers.
1. Many different types of protein molecules are made within cells. Which of the following could
be influenced by the actions of those protein molecules?
a. Both an organism's physical characteristics and the function of the organism's cells
b. An organism's physical characteristics but not the function of the organism's cells
c. The function of the organism's cells but not the organism's physical characteristics
d. Neither an organism's physical characteristics nor the function of the organism's cells -
Answer a. Both an organism's physical characteristics and the function of the organism's cells
Proteins have a variety of functions inside cells. The function of some proteins can be seen as an
observable, physical characteristic.
2. What happens to the intron sections of genes?
a. They are neither transcribed nor translated
b. They are transcribed and translated
c. They are transcribed but not translated
d. They are not transcribed but they are translated. - Answer c. They are transcribed but not
translated
They are removed from the primary transcript during splicing.
3. The DNA molecules in eye cells contain which of the following?
a. Genes that encode eye color and skin color, and switches that control both eye color and skin
color
b. Genes that encode eye color and skin color, and switches that control eye color only (not skin
color)
c. Genes and switches that encode eye color only (not skin color)
d. Genes that control eye and skin color, but not switches for either of these genes. - Answer
a. Genes that encode eye color and skin color, and switches that control both eye color and skin
color
Switches are DNA sequences. The DNA in every body cell is, for the most part, the same.
4. Which of the following is a part of a DNA molecule?
,a. Promoter
b. Switch
c. Gene
d. All of the above
e. A and C only - Answer d. All of the above
5. 5' caps and 3' poly(A) tails of eukaryotic mRNAs ______.
a. protect mRNA from degradation and enhance transcription
b. mark the beginning and end of introns, respectively
c. act as sites for the start and stop of translation, respectively
d. protect mRNA from degradation and enhance translation - Answer d. protect mRNA from
degradation and enhance translation
We didn't specifically talk about them enhancing translation (but they do). They definitely
protect the RNA from degradation. It wouldn't make sense for them to enhance transcription
because they are put on after transcription occurs.
6. Different cells in the same organism express different proteins in part because:
a. their genomes are different
b. they contain different gene switches
c. different gene switches are activated
d. they use different genetic codes
e. b and c only - Answer c. different gene switches are activated
All body cells from an organism have the same DNA. Since switches are part of the DNA, all cells
have the same switches. All organisms use the same genetic code, so d cannot be true.
The activation of switches by activator proteins helps explain why different cells from the same
organism express different proteins.
7. Which of the following is TRUE about translation in eukaryotes?
a. The first amino acid translated from all mRNAs is the same
b. Translation begins at the very 5' end of all mRNAs
c. Translation terminates (stops) after the polyA tail is translated into amino acids
d. Each nucleotide in an mRNA specifies one amino acid
e. There are 20 different codons in mRNA, corresponding to the 20 different amino acids -
Answer a. The first amino acid translated from all mRNAs is the same
, Since AUG is the only start codon, all newly synthesized polypeptides start with a Met amino
acid. B isn't true because translation starts at the start codon, not the very 5' end of the RNA. C
isn't true because translation stops at a stop codon. D isn't true because it's the combination of
three nucleotides that codes for one amino acid. D isn't true because there are 64 codons.
8. Which of the following about gene switches is TRUE?
a. They are proteins
b. RNA polymerase binds to them directly
c. They are located within the promoter
d. They regulate the number of times an RNA is translated
e. They can be bound by activator proteins to "turn on" transcription - Answer e. They can
be bound by activator proteins to "turn on" transcription
9. At what point in the central dogma does addition of the poly(A) tail occur?
a. Between the gene and synthesis of the primary transcript
b. Between synthesis of the primary transcript and formation of the mature mRNA
c. Between formation of the mature mRNA and synthesis of the polypeptide
d. Between synthesis of the polypeptide and formation of the finished protein - Answer b.
Between synthesis of the primary transcript and formation of the mature mRNA
Poly(A) tail addition is part of processing that prepares a primary transcript, converting it to a
mature mRNA
10. Which of the following would you expect to find in a mature mRNA?
a. Introns
b. Promoters
c. Codons
d. Amino acids
e. Switches - Answer c. Codons
Promoters and switches are not transcribed, so they can't be there. Introns aren't there either,
because they have been spliced out. Amino acids are part of proteins, not RNA.
Refer to the genetic code in this exam regarding the section of mRNA directly below.
5' UCUGAUGGGCUUU...
