Question 1

Which of the following mutations would be most likely to have a harmful effect on an organism?

Accepted Answer

A)  a nucleotide-pair substitution 
B)  a deletion of three nucleotides near the middle of a gene 
C)  a single nucleotide deletion in the middle of an intron 
D)  a single nucleotide deletion near the end of the coding sequence 
E)  a single nucleotide insertion downstream of, and close to, the start of the coding sequence 
A)  a nucleotide-pair substitution 
B)  a deletion of three nucleotides near the middle of a gene 
C)  a single nucleotide deletion in the middle of an intron 
D)  a single nucleotide deletion near the end of the coding sequence 
E)  a single nucleotide insertion downstream of, and close to, the start of the coding sequence

Question 2

According to the central dogma, what molecule should go in the blank?
DNA → ________ → Proteins

Accepted Answer

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

Question 3

A mutation that results in premature termination of translation ________.

Accepted Answer

A)  is a silent mutation 
B)  is a nonsense mutation 
C)  usually has no effect on the function of the protein 
D)  is a missense mutation 
A)  is a silent mutation 
B)  is a nonsense mutation 
C)  usually has no effect on the function of the protein 
D)  is a missense mutation

Question 4

HIV, the causative agent of AIDS, is a retrovirus. A retrovirus ________.

Accepted Answer

A)  uses DNA as a template in the process of translation 
B)  makes proteins directly from RNA 
C)  uses reverse transcriptase to make DNA from RNA 
D)  is a cellular virus that uses ribosomes to reproduce inside a living cell 
A)  uses DNA as a template in the process of translation 
B)  makes proteins directly from RNA 
C)  uses reverse transcriptase to make DNA from RNA 
D)  is a cellular virus that uses ribosomes to reproduce inside a living cell

Question 5

Why might a point mutation in DNA make a difference in the level of a protein's activity?

Accepted Answer

A)  It might result in a chromosomal translocation. 
B)  It might exchange one stop codon for another stop codon. 
C)  It might delay the rate of DNA replication. 
D)  It might substitute a different amino acid in the active site. 
E)  It might substitute the N-terminus of the polypeptide for the C-terminus. 
A)  It might result in a chromosomal translocation. 
B)  It might exchange one stop codon for another stop codon. 
C)  It might delay the rate of DNA replication. 
D)  It might substitute a different amino acid in the active site. 
E)  It might substitute the N-terminus of the polypeptide for the C-terminus.

Question 6

Which of the following is NOT synthesized from a DNA template?

Accepted Answer

A)  messenger RNA 
B)  amino acids 
C)  transfer RNA 
D)  ribosomal RNA 
A)  messenger RNA 
B)  amino acids 
C)  transfer RNA 
D)  ribosomal RNA

Question 7

Knockout mice have been genetically altered to knock out specific genes. How are these mice most often used in research?

Accepted Answer

A)  to study DNA replication in the defective genes (those that have been altered) 
B)  to determine the role of proteins coded for by those genes that are knocked out 
C)  to examine defects in DNA structure in those regions that have been altered 
D)  to study the effect of radiation on DNA 
A)  to study DNA replication in the defective genes (those that have been altered) 
B)  to determine the role of proteins coded for by those genes that are knocked out 
C)  to examine defects in DNA structure in those regions that have been altered 
D)  to study the effect of radiation on DNA

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

Refer to the associated figure. A branched metabolic pathway synthesizes two related amino acids (D and F) If there is a genetic defect, resulting in a nonfunctional enzyme (3), how could you ensure that adequate amounts of the amino acid F are synthesized?

Accepted Answer

A)  supplement intermediate B 
B)  supplement intermediate C 
C)  add enzyme 2 to the medium 
D)  supplement with intermediate E 
A)  supplement intermediate B 
B)  supplement intermediate C 
C)  add enzyme 2 to the medium 
D)  supplement with intermediate E

Question 10

Refer to the associated figure. In the branched metabolic pathway indicated in the figure, 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 or product?

Accepted Answer

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

Question 11

In the first step of their experiments, Jacob and Monod treated E. coli cells with ultraviolet light or X-rays to ________.

Accepted Answer

A)  decrease the rate of gene expression 
B)  induce DNA repair enzymes 
C)  increase the frequency of mutations in all genes 
D)  selectively mutate specific genes, leaving all other genes unmutated 
A)  decrease the rate of gene expression 
B)  induce DNA repair enzymes 
C)  increase the frequency of mutations in all genes 
D)  selectively mutate specific genes, leaving all other genes unmutated

Question 12

How does the simple primary and secondary structure of DNA hold the information needed to code for the many features of multicellular organisms?

Accepted Answer

A)  The hydrogen bonding among backbone constituents carries coded information. 
B)  The base sequence of DNA carries the information needed to code for proteins. 
C)  The width of the double helix changes at each gene due to differences in hydrogen bonds. 
D)  The amino acids that make up the DNA molecule contain the information needed to make cellular proteins. 
A)  The hydrogen bonding among backbone constituents carries coded information. 
B)  The base sequence of DNA carries the information needed to code for proteins. 
C)  The width of the double helix changes at each gene due to differences in hydrogen bonds. 
D)  The amino acids that make up the DNA molecule contain the information needed to make cellular proteins.

Question 13

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?

Accepted Answer

A)  a deletion of a codon 
B)  a deletion of two nucleotides 
C)  a substitution of the third nucleotide in an ACC codon 
D)  a substitution of the first nucleotide of a GGG codon 
E)  an insertion of a codon 
A)  a deletion of a codon 
B)  a deletion of two nucleotides 
C)  a substitution of the third nucleotide in an ACC codon 
D)  a substitution of the first nucleotide of a GGG codon 
E)  an insertion of a codon

Question 14

Point mutations are referred to as missense, silent, frameshift, or nonsense when they change the protein-coding potential of a gene. What is another group of mutations that may have important consequences for gene expression?

Accepted Answer

A)  mutations that exist outside coding sequences 
B)  combinations of missense and silent mutations 
C)  combinations of nonsense and silent mutations 
D)  mutations that alter the amino acid sequence of a gene 
E)  mutations that shift the reading frame of a gene 
A)  mutations that exist outside coding sequences 
B)  combinations of missense and silent mutations 
C)  combinations of nonsense and silent mutations 
D)  mutations that alter the amino acid sequence of a gene 
E)  mutations that shift the reading frame of a gene

Question 15

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is ________.

Accepted Answer

A)  3' UCA 5' 
B)  3' UGS 5' 
C)  5' TCA 3' 
D)  3' ACU 5' 
E)  either UCA or TCA, depending on wobble in the first base 
A)  3' UCA 5' 
B)  3' UGS 5' 
C)  5' TCA 3' 
D)  3' ACU 5' 
E)  either UCA or TCA, depending on wobble in the first base

Question 16

Genotype is to ________ as phenotype is to ________.

Accepted Answer

A)  DNA base sequence; physical traits that are products of the proteins produced 
B)  heredity; DNA base sequence 
C)  gene regulation; translation 
D)  transcription; amino acid sequence 
A)  DNA base sequence; physical traits that are products of the proteins produced 
B)  heredity; DNA base sequence 
C)  gene regulation; translation 
D)  transcription; amino acid sequence

Question 17

Consider the following section of mRNA:
UCUGAUGGGCUUU…
Beginning with the start codon, which amino acids, in order, are coded for by this section of mRNA? Consult the codon table provided if necessary.

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 18

The following question(s) refer to this table of codons.  
-A peptide has the sequence NH2-phe-pro-lys-gly-phe-pro-COOH. Which of the following sequences in the coding strand of the DNA could code for this peptide?

Accepted Answer

A)  3' UUU-CCC-AAA-GGG-UUU-CCC 
B)  3' AUG-AAA-GGG-TTT-CCC-AAA-GGG 
C)  5' TTT-CCC-AAA-GGG-TTT-CCC 
D)  5' GGG-AAA-TTT-AAA-CCC-ACT-GGG 
E)  5' ACT-TAC-CAT-AAA-CAT-TAC-UGA 
A)  3' UUU-CCC-AAA-GGG-UUU-CCC 
B)  3' AUG-AAA-GGG-TTT-CCC-AAA-GGG 
C)  5' TTT-CCC-AAA-GGG-TTT-CCC 
D)  5' GGG-AAA-TTT-AAA-CCC-ACT-GGG 
E)  5' ACT-TAC-CAT-AAA-CAT-TAC-UGA

Question 19

In the Morse code, a series of dots and dashes code for letters of the alphabet. How is this analogous to the genetic code?

Accepted Answer

A)  There is complementarity in the genetic code (A is complementary to T, and C is complementary to G). 
B)  The bases that make up DNA are coded by the sugar-phosphate backbone. 
C)  The machinery involved in DNA synthesis is analogous to the telegraph equipment used in sending Morse code. 
D)  The bases of DNA code for the more complex amino acid sequence of the proteins in cells. 
A)  There is complementarity in the genetic code (A is complementary to T, and C is complementary to G). 
B)  The bases that make up DNA are coded by the sugar-phosphate backbone. 
C)  The machinery involved in DNA synthesis is analogous to the telegraph equipment used in sending Morse code. 
D)  The bases of DNA code for the more complex amino acid sequence of the proteins in cells.

Question 20

The mutation resulting in sickle cell disease changes one base pair of DNA so that a codon now codes for a different amino acid, making it an example of a ________.

Accepted Answer

A)  nonsense mutation 
B)  frameshift mutation 
C)  silent mutation 
D)  missense mutation 
A)  nonsense mutation 
B)  frameshift mutation 
C)  silent mutation 
D)  missense mutation

Exam 16: How Genes Work

Which of the following mutations would be most likely to have a harmful effect on an organism?

According to the central dogma, what molecule should go in the blank? DNA → ________ → Proteins

A mutation that results in premature termination of translation ________.

HIV, the causative agent of AIDS, is a retrovirus. A retrovirus ________.

Why might a point mutation in DNA make a difference in the level of a protein's activity?

Which of the following is NOT synthesized from a DNA template?

Knockout mice have been genetically altered to knock out specific genes. How are these mice most often used in research?

In the process of transcription, ________.

Refer to the associated figure. A branched metabolic pathway synthesizes two related amino acids (D and F) If there is a genetic defect, resulting in a nonfunctional enzyme (3), how could you ensure that adequate amounts of the amino acid F are synthesized?

Refer to the associated figure. In the branched metabolic pathway indicated in the figure, 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 or product?

In the first step of their experiments, Jacob and Monod treated E. coli cells with ultraviolet light or X-rays to ________.

How does the simple primary and secondary structure of DNA hold the information needed to code for the many features of multicellular organisms?

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?

Point mutations are referred to as missense, silent, frameshift, or nonsense when they change the protein-coding potential of a gene. What is another group of mutations that may have important consequences for gene expression?

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is ________.

Genotype is to ________ as phenotype is to ________.

Consider the following section of mRNA: UCUGAUGGGCUUU… Beginning with the start codon, which amino acids, in order, are coded for by this section of mRNA? Consult the codon table provided if necessary.

The following question(s) refer to this table of codons. -A peptide has the sequence NH2-phe-pro-lys-gly-phe-pro-COOH. Which of the following sequences in the coding strand of the DNA could code for this peptide?

In the Morse code, a series of dots and dashes code for letters of the alphabet. How is this analogous to the genetic code?

The mutation resulting in sickle cell disease changes one base pair of DNA so that a codon now codes for a different amino acid, making it an example of a ________.

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

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land 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 and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

Filters

Genotype is to as phenotype is to .