Question 1

The genetic code is nearly universal.

Accepted Answer

A) True 
 B)False  True

Question 2

The lac operon

Accepted Answer

A)  is an example of positive control. 
B)  produces lactose. 
C)  is an example of a regulon. 
D)  is an example of negative control. 
E)  is an example of constitutive control. 
A)  is an example of positive control. 
B)  produces lactose. 
C)  is an example of a regulon. 
D)  is an example of negative control. 
E)  is an example of constitutive control. D

Question 3

Which of the following is/are True of DNA replication?

Accepted Answer

A)  It starts at the origin of duplication. 
B)  Nucleotides are added to the 3' end. 
C)  It requires a DNA primer to get started. 
D)  It is carried out by transcriptases. 
E)  All of the choices are True. 
A)  It starts at the origin of duplication. 
B)  Nucleotides are added to the 3' end. 
C)  It requires a DNA primer to get started. 
D)  It is carried out by transcriptases. 
E)  All of the choices are True. B

Question 4

A regulatory protein binds to the operator in a strand of DNA, blocking transcription. The protein is

Accepted Answer

A)  a repressor. 
B)  an inducer. 
C)  an operon. 
D)  a terminator. 
E)  an activator. 
A)  a repressor. 
B)  an inducer. 
C)  an operon. 
D)  a terminator. 
E)  an activator.

Question 5

Why is it a good idea for a bacterial cell to be able to use glucose FIRST as an energy source (until it is depleted), THEN switch to lactose?

Accepted Answer

A)  Lactose can only be used by a small number of bacteria as an energy source AND for conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown? 
B)  For conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown AND because breakdown of lactose produces inhibitory compounds. 
C)  Glucose is an easier compound to break down and obtain energy from than lactose AND for conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown? 
D)  Glucose provides 10x as much energy when broken down as lactose AND for conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown? 
E)  For conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown AND because lactose always triggers endospore formation, which may be unnecessary. 
A)  Lactose can only be used by a small number of bacteria as an energy source AND for conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown? 
B)  For conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown AND because breakdown of lactose produces inhibitory compounds. 
C)  Glucose is an easier compound to break down and obtain energy from than lactose AND for conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown? 
D)  Glucose provides 10x as much energy when broken down as lactose AND for conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown? 
E)  For conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown AND because lactose always triggers endospore formation, which may be unnecessary.

Question 6

CAP

Accepted Answer

A)  is involved in positive control AND stands for cyclic amp protein. 
B)  is involved in positive control AND works in conjunction with cAMP. 
C)  stands for cyclic amp protein AND is a regulon. 
D)  stands for cyclic amp protein AND works in conjunction with cAMP. 
E)  is involved in negative control AND works in conjunction with cAMP. 
A)  is involved in positive control AND stands for cyclic amp protein. 
B)  is involved in positive control AND works in conjunction with cAMP. 
C)  stands for cyclic amp protein AND is a regulon. 
D)  stands for cyclic amp protein AND works in conjunction with cAMP. 
E)  is involved in negative control AND works in conjunction with cAMP.

Question 7

AUG

Accepted Answer

A)  is only used as the start codon. 
B)  codes for methionine. 
C)  determines the reading frame. 
D)  is one of the stop codons. 
E)  codes for methionine AND determines the reading frame. 
A)  is only used as the start codon. 
B)  codes for methionine. 
C)  determines the reading frame. 
D)  is one of the stop codons. 
E)  codes for methionine AND determines the reading frame.

Question 8

The term antiparallel

Accepted Answer

A)  refers to the structure of single-stranded RNA. 
B)  is synonymous with semiconservative. 
C)  refers to the opposite orientation of the two strands in DNA. 
D)  refers to a type of prokaryotic replication. 
E)  refers to the sequence of nucleotides in DNA. 
A)  refers to the structure of single-stranded RNA. 
B)  is synonymous with semiconservative. 
C)  refers to the opposite orientation of the two strands in DNA. 
D)  refers to a type of prokaryotic replication. 
E)  refers to the sequence of nucleotides in DNA.

Question 9

Cells are often ground up with abrasive to get to their internal enzymes/molecules, followed by removal of the abrasives. Here are three situations and three outcomes. What is the correct interpretation of the results?
In situation #1, radioactive amino acids are added to cell material, and radioactive proteins are produced.
In situation #2, radioactive amino acids, cell material, and the enzyme DNAse (degrades DNA) are added together. Radioactive proteins are still produced.
In situation #3, the ground-up cell material is allowed to sit for 24 hours before radioactive amino acids and DNAse are added to it. No radioactive protein is produced. What is the most likely interpretation?

Accepted Answer

A)  RNA polymerase has no activity after 24 hours, so no mRNA is transcribed and translated into radioactive proteins in the last scenario. 
B)  The radioactivity in the amino acids is altering/degrading the tRNA molecules, leading to no protein production in the last scenario. 
C)  Natural RNAses present in the ground-up material will degrade any existing mRNAs in that 24-hour interval. Added DNAses break down DNA so that new RNAs are not synthesized. This will lead to a loss of capability to translate protein in the last scenario. 
D)  The radioactivity in the amino acids completely disappears within 24 hours. Transcription and translation occur as usual, but there is no radioactivity left in the system, so proteins are untagged. 
E)  No conclusions can be made from the information given. More results are needed to interpret these experiments. 
A)  RNA polymerase has no activity after 24 hours, so no mRNA is transcribed and translated into radioactive proteins in the last scenario. 
B)  The radioactivity in the amino acids is altering/degrading the tRNA molecules, leading to no protein production in the last scenario. 
C)  Natural RNAses present in the ground-up material will degrade any existing mRNAs in that 24-hour interval. Added DNAses break down DNA so that new RNAs are not synthesized. This will lead to a loss of capability to translate protein in the last scenario. 
D)  The radioactivity in the amino acids completely disappears within 24 hours. Transcription and translation occur as usual, but there is no radioactivity left in the system, so proteins are untagged. 
E)  No conclusions can be made from the information given. More results are needed to interpret these experiments.

Question 10

Your patient has a fever of 39S1U1P1oS1S1P0C, sore throat, cough, and chest pain. You ask her whether she has had pneumococcal vaccine this year, which protects against the the 23 most common strains of the causative bacterium Streptococcus pneumoniae. She says she has not. Your patient has a number of questions that you answer to help her understand the genetics of the organism causing her illness.
-You give your patient some general information on gene expression in cells. You explain that when cells divide, two processes are involved: replication and gene expression. Gene expression includes two related events: (i) copying the information encoded in DNA into RNA, a process called ________, followed by (ii) the interpretation of the information carried by the RNA to synthesize the encoded protein in a process called ________.

Accepted Answer

A)  transcription; translation 
B)  translation, transcription 
C)  replication; transcription 
D)  replication; translation 
E)  binary fission; transcription 
A)  transcription; translation 
B)  translation, transcription 
C)  replication; transcription 
D)  replication; translation 
E)  binary fission; transcription

Question 11

Your patient has a fever of 39S1U1P1oS1S1P0C, sore throat, cough, and chest pain. You ask her whether she has had pneumococcal vaccine this year, which protects against the the 23 most common strains of the causative bacterium Streptococcus pneumoniae. She says she has not. Your patient has a number of questions that you answer to help her understand the genetics of the organism causing her illness.
-Your patient took biology many years ago. You remind her of the structure of DNA and RNA. Which statement is NOT correct?

Accepted Answer

A)  DNA is usually a double-stranded, helical structure composed of nucleotides, each of which contains a sugar, a phosphate group, and a nucleobase (A, T, C or G). 
B)  The two strands of DNA are complementary and are held together by hydrogen bonds between the nucleobases. 
C)  RNA is a single-stranded molecule composed of nucleotides that contain the nucleobases adenine, thymine, uracil, or cytosine. 
D)  RNA nucleotides contain the 5-C sugar ribose while DNA nucleotides contain the 5-C sugar deoxyribose. 
E)  A single linear strand of DNA will always have a 5′PO4 at one end and a 3′OH at the other, referred to as the 5′ end (5 prime end) and the 3′ end (3 prime end) respectively. 
A)  DNA is usually a double-stranded, helical structure composed of nucleotides, each of which contains a sugar, a phosphate group, and a nucleobase (A, T, C or G). 
B)  The two strands of DNA are complementary and are held together by hydrogen bonds between the nucleobases. 
C)  RNA is a single-stranded molecule composed of nucleotides that contain the nucleobases adenine, thymine, uracil, or cytosine. 
D)  RNA nucleotides contain the 5-C sugar ribose while DNA nucleotides contain the 5-C sugar deoxyribose. 
E)  A single linear strand of DNA will always have a 5′PO4 at one end and a 3′OH at the other, referred to as the 5′ end (5 prime end) and the 3′ end (3 prime end) respectively.

Question 12

What is the number of tRNA molecules that may be associated with translation?

Accepted Answer

A)  20 
B)  Fewer than 20 
C)  64 
D)  Fewer than 64 
E)  2 
A)  20 
B)  Fewer than 20 
C)  64 
D)  Fewer than 64 
E)  2

Question 13

Bacteria use ________ attached to the polymerase to direct RNA polymerase to promoters; eukaryotic cells use ________ that attach directly to the DNA first instead.

Accepted Answer

A)  sigma factors; transcription factors 
B)  transcription factors; sigma factors 
C)  ribosomes; sigma factors 
D)  tRNA; rRNA 
E)  sigma factors; tRNA 
A)  sigma factors; transcription factors 
B)  transcription factors; sigma factors 
C)  ribosomes; sigma factors 
D)  tRNA; rRNA 
E)  sigma factors; tRNA

Question 14

DNA replication is usually unidirectional.

Accepted Answer

A) True 
 B)False

Question 15

A codon consists of two nucleotides.

Accepted Answer

A) True 
 B)False

Question 16

A stop codon

Accepted Answer

A)  codes for the stop amino acid s-methyl-methionine. 
B)  forms a hairpin loop forcing the ribosome to fall off. 
C)  codes for no amino acid. 
D)  enhances the binding of the e-polymerase. 
E)  codes for the stop amino acid AUG. 
A)  codes for the stop amino acid s-methyl-methionine. 
B)  forms a hairpin loop forcing the ribosome to fall off. 
C)  codes for no amino acid. 
D)  enhances the binding of the e-polymerase. 
E)  codes for the stop amino acid AUG.

Question 17

All of the following are True about DNA sequence analysis EXCEPT

Accepted Answer

A)  the (−) strand of DNA is used. 
B)  the start codon is ATG. 
C)  ORFs are searched for. 
D)  codon usage is a helpful indicator for protein coding areas. 
E)  All of the answer choices are correct. 
A)  the (−) strand of DNA is used. 
B)  the start codon is ATG. 
C)  ORFs are searched for. 
D)  codon usage is a helpful indicator for protein coding areas. 
E)  All of the answer choices are correct.

Question 18

The genetic code has more than one codon for some amino acids. This is an example of

Accepted Answer

A)  evolution. 
B)  stringency. 
C)  redundancy. 
D)  translation. 
E)  replication. 
A)  evolution. 
B)  stringency. 
C)  redundancy. 
D)  translation. 
E)  replication.

Question 19

Which may be or is an RNA molecule?

Accepted Answer

A)  AGCCTAC and GGGCCCA 
B)  GGGCCCA and AAATTTA 
C)  GGGCCCA and GCCCUUA 
D)  GCCCUUA and AAATTTA 
E)  AGCCTAC and GGUCCCU 
A)  AGCCTAC and GGGCCCA 
B)  GGGCCCA and AAATTTA 
C)  GGGCCCA and GCCCUUA 
D)  GCCCUUA and AAATTTA 
E)  AGCCTAC and GGUCCCU

Question 20

Does the presence of introns/exons in eukaryotic cells provide more potential diversity in gene products (proteins) than is possible in prokaryotic cells?

Accepted Answer

A)  It doesn't. There is the same potential for gene products (proteins) in a bacterium with 1,000 genes as there is in a eukaryotic cell with 1,000 genes. 
B)  It does. Each exon and each intron could be used individually and discretely to make a gene product (protein). Since bacteria lack these, they will have less ability to create different proteins. 
C)  It does. Exons/introns can be spliced together in different ways post-transcription to yield different mRNAs (and therefore, different proteins). Bacteria lack this system. 
D)  It does. Exons/introns can be spliced together in different ways at the DNA level to eventually yield different mRNAs (and therefore, different proteins). Bacteria lack this system. 
E)  It doesn't. Bacteria and eukaryotes have the same number of introns and exons, and can thus synthesize the same types and numbers of proteins. 
A)  It doesn't. There is the same potential for gene products (proteins) in a bacterium with 1,000 genes as there is in a eukaryotic cell with 1,000 genes. 
B)  It does. Each exon and each intron could be used individually and discretely to make a gene product (protein). Since bacteria lack these, they will have less ability to create different proteins. 
C)  It does. Exons/introns can be spliced together in different ways post-transcription to yield different mRNAs (and therefore, different proteins). Bacteria lack this system. 
D)  It does. Exons/introns can be spliced together in different ways at the DNA level to eventually yield different mRNAs (and therefore, different proteins). Bacteria lack this system. 
E)  It doesn't. Bacteria and eukaryotes have the same number of introns and exons, and can thus synthesize the same types and numbers of proteins.

Exam 7: The Blueprint of Life, from DNA to Protein

The genetic code is nearly universal.

The lac operon

Which of the following is/are True of DNA replication?

A regulatory protein binds to the operator in a strand of DNA, blocking transcription. The protein is

Why is it a good idea for a bacterial cell to be able to use glucose FIRST as an energy source (until it is depleted), THEN switch to lactose?

CAP

AUG

The term antiparallel

What is the number of tRNA molecules that may be associated with translation?

Bacteria use ________ attached to the polymerase to direct RNA polymerase to promoters; eukaryotic cells use ________ that attach directly to the DNA first instead.

DNA replication is usually unidirectional.

A codon consists of two nucleotides.

A stop codon

All of the following are True about DNA sequence analysis EXCEPT

The genetic code has more than one codon for some amino acids. This is an example of

Which may be or is an RNA molecule?

Does the presence of introns/exons in eukaryotic cells provide more potential diversity in gene products (proteins) than is possible in prokaryotic cells?

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Microbial Growth

Control of Microbial Growth

Microbial Metabolism: Fueling Cell Growth

Bacterial Genetics

Biotechnology

Identifying and Classifying Microorganisms

The Diversity of Bacteria and Archaea

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunological Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Blood and Lymphatic Infections

Nervous System Infections

Genitourinary Tract Infections

Microbial Ecology

Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Food Microbiology

Filters

Bacteria use attached to the polymerase to direct RNA polymerase to promoters; eukaryotic cells use that attach directly to the DNA first instead.