Question 1

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

Accepted Answer

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. 
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 2

When is a single base substitution mutation least likely to be deleterious?

Accepted Answer

A) when the single base change results in a stop codon 
B) when the single base change results in a codon that specifies the same amino acid as the original codon 
C) when the base change results in an amino acid substitution that alters the tertiary structure of the protein 
D) when the base change results in an amino acid substitution at the active site of an enzyme 
A) when the single base change results in a stop codon 
B) when the single base change results in a codon that specifies the same amino acid as the original codon 
C) when the base change results in an amino acid substitution that alters the tertiary structure of the protein 
D) when the base change results in an amino acid substitution at the active site of an enzyme

Question 3

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 why?

Accepted Answer

A) Only a single amino acid could change,because the reading frame is unaffected. 
B) The amino acid sequence would be substantially altered,because the reading frame would change with a single base substitution. 
C) All amino acids following the substitution would be affected,because the reading frame would be shifted. 
D) It is not possible for a single base substitution to affect protein structure,because each codon is three bases long. 
A) Only a single amino acid could change,because the reading frame is unaffected. 
B) The amino acid sequence would be substantially altered,because the reading frame would change with a single base substitution. 
C) All amino acids following the substitution would be affected,because the reading frame would be shifted. 
D) It is not possible for a single base substitution to affect protein structure,because each codon is three bases long.

Question 4

Figure 15.5.
Use the figure to answer the following question(s).
  
-Refer to Figure 15.5.If you had a mRNA for which the codons were read beginning from the start codon,which amino acids would be added (in order)? UCUGAUGGGCUUU…

Accepted Answer

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

Question 5

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

Accepted Answer

A) the base sequence of the tRNA 
B) the amino acetyl tRNA synthase 
C) the three-base sequence of mRNA 
D) the complementarity of DNA and RNA 
A) the base sequence of the tRNA 
B) the amino acetyl tRNA synthase 
C) the three-base sequence of mRNA 
D) the complementarity of DNA and RNA

Question 6

Figure 15.5.
Use the figure to answer the following question(s).
  
-Refer to Figure 15.5.If a DNA sequence is GAG,then the amino acid it codes for is _____.

Accepted Answer

A) phenylalanine 
B) methionine 
C) aspartic acid 
D) histidine 
A) phenylalanine 
B) methionine 
C) aspartic acid 
D) histidine

Question 7

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

Accepted Answer

A) A codon of 2 bases in length,from 4 different bases,would code for a maximum of 16 different amino acids. 
B) A codon of 3 bases in length,from 4 different bases,would code for a maximum of 12 different amino acids. 
C) A codon of 4 bases in length,from 4 different bases,would code for a maximum of 24 different amino acids. 
D) A codon of 3 bases in length,from 4 different bases,would code for a maximum of 64 different amino acids. 
A) A codon of 2 bases in length,from 4 different bases,would code for a maximum of 16 different amino acids. 
B) A codon of 3 bases in length,from 4 different bases,would code for a maximum of 12 different amino acids. 
C) A codon of 4 bases in length,from 4 different bases,would code for a maximum of 24 different amino acids. 
D) A codon of 3 bases in length,from 4 different bases,would code for a maximum of 64 different amino acids.

Question 8

In the process of transcription,_____.

Accepted Answer

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

Question 9

Figure 15.2
  
-Refer to Figure 15.2.In the branched metabolic pathway,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/product?

Accepted Answer

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

Question 10

Figure 15.5.
Use the figure to answer the following question(s).
  
-Refer to Figure 15.5.Transfer RNA contains the anticodon XXX (three-base sequence that is complementary to the mRNA codon).tRNA with which anticodon would transport phenylalanine to the ribosome?

Accepted Answer

A) UUU 
B) AAA 
C) TTT 
D) CCC 
A) UUU 
B) AAA 
C) TTT 
D) CCC

Question 11

Which of the following findings violated the central dogma?

Accepted Answer

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 
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 12

Which of the following molecules must move across the membrane after being synthesized from a DNA sequence and is then translated by a ribosome?

Accepted Answer

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

Question 13

The central dogma has been challenged on several levels (e.g. ,the discovery of RNA viruses,which use their RNA to directly synthesize proteins;and the discovery of reverse transcriptase,which makes DNA from RNA).Which of the following is another example of an exception to the central dogma?

Accepted Answer

A) DNA from viruses can insert themselves into host cell chromosomes. 
B) Chaperone molecules guide the folding of protein molecules. 
C) Gene mutations result in altered amino acid sequences of proteins. 
D) Prions are infectious protein molecules capable of altering the folding of normal proteins. 
A) DNA from viruses can insert themselves into host cell chromosomes. 
B) Chaperone molecules guide the folding of protein molecules. 
C) Gene mutations result in altered amino acid sequences of proteins. 
D) Prions are infectious protein molecules capable of altering the folding of normal proteins.

Question 14

All three domains (Bacteria,Archaea,and Eukarya)follow the same genetic code.Which of the following statements would most likely be accurate given that information?

Accepted Answer

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. 
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.

Exam 15: How Genes Work

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

When is a single base substitution mutation least likely to be deleterious?

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 why?

Figure 15.5. Use the figure to answer the following question(s). -Refer to Figure 15.5.If you had a mRNA for which the codons were read beginning from the start codon,which amino acids would be added (in order)? UCUGAUGGGCUUU…

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

Figure 15.5. Use the figure to answer the following question(s). -Refer to Figure 15.5.If a DNA sequence is GAG,then the amino acid it codes for is _____.

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

In the process of transcription,_____.

Figure 15.2 -Refer to Figure 15.2.In the branched metabolic pathway,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/product?

Figure 15.5. Use the figure to answer the following question(s). -Refer to Figure 15.5.Transfer RNA contains the anticodon XXX (three-base sequence that is complementary to the mRNA codon).tRNA with which anticodon would transport phenylalanine to the ribosome?

Which of the following findings violated the central dogma?

Which of the following molecules must move across the membrane after being synthesized from a DNA sequence and is then translated by a ribosome?

The central dogma has been challenged on several levels (e.g. ,the discovery of RNA viruses,which use their RNA to directly synthesize proteins;and the discovery of reverse transcriptase,which makes DNA from RNA).Which of the following is another example of an exception to the central dogma?

All three domains (Bacteria,Archaea,and Eukarya)follow the same genetic code.Which of the following statements would most likely be accurate given that information?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, membranes, and the First Cells

Inside the Cell

Cell-Cell Interactions

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

Transcription and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

Analyzing and Engineering Genes

Genomics

Principles of Development

An Introduction to Animal Development

An Introduction to Plant Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, signals, and Responses

Plant Reproduction

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Electrical Signals in Animals

Animal Sensory Systems and Movement

Chemical Signals in Animals

Animal Reproduction

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

Filters