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BIO 235 - Final Exam Study Guide ALL 200
QUESTIONS AND CORRECT ANSWERS LATEST
UPDATE THIS YEAR
BIO 235 - Final Exam Study Guide
QUESTION: Through wobble, a single __________ can pair wit more than one __________.
A. codon; anticodon
B. group of three nucleotides in DNA; codon in mRNA
C. tRNA; amino acid
D. Anticodon; codon - ANSWER-D
QUESTION: The increase in number (expansion) of three-nucleotide repeats is responsible for?
A. Sickle-cell anemia
B. Xeroderma pigmentosum
C. Alkaptonuria
D. Trisomy 21
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E. Fragile X syndrome
F. None of the above - ANSWER-E
QUESTION: How many copies of the CGG repeat does a normal/unaffected person? (fragile X
syndrome) - ANSWER-Less than 55 (60)
QUESTION: How many copies of the CGG repeat does a premutated individual have? (fragile X
syndrome) - ANSWER-55-230
QUESTION: How many copies of the CGG repeat does an affected individual have? (fragile X
syndrome) - ANSWER-more than 230
QUESTION: Are somatic mutations inherited? - ANSWER-NO (produce patches - basis for
cancers)
QUESTION: Are germ-line mutations inherited? - ANSWER-YES
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QUESTION: Intragenic suppressor mutation - ANSWER-Takes place in the same gene as that
containing the mutation being suppressed (may change a second nucleotide in the SAME codon
altered by the original mutation OR suppress a frameshift mutation with an insertion or
deletion)
QUESTION: Intergenic suppressor mutation - ANSWER-Occurs in a gene other than the one
bearing the original
QUESTION: What causes xeroderma pigmentosum? - ANSWER-Autosomal recessive condition
where people lack nucleotide-excision repair enzymes
QUESTION: The Ames test relies on the rate of a mutation in a bacterium. What is the direction
of this mutation?
A. Auxotrophic bacterial cells turn into prototrophs
B. Prototrophic bacterial cells turn into auxotrophs
C. Heterotrophic organisms turn into phototrophic organism
D. A wild-type bacterium turns into a mutant bacterium
E. A heterozygous organism turns into homozygous one - ANSWER-A (his- to his+)
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QUESTION: A silent mutation is a nucleotide change in the DNA sequence which
A. Does not result in an amino change
B. Converts a sense codon to a non-sense codon
C. Causes a missense mutation, but the altered amino acid has similar characteristics as the
wild-type amino acid, and the altered polypeptide remains functional
D. Causes a missense mutation, and the altered amino acid differs from the wild-type amino
acid, and the altered polypeptide is dysfunctional
E. Results in a frameshift - ANSWER-A
QUESTION: Insertion - ANSWER-Addition of a nucleotide pair
QUESTION: Deletion - ANSWER-Deletion of a nucleotide pair
QUESTION: Frameshift mutations - ANSWER-Changes in the reading frame of a gene (results
from an insertion or a deletion)
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BIO 235 - Final Exam Study Guide ALL 200
QUESTIONS AND CORRECT ANSWERS LATEST
UPDATE THIS YEAR
BIO 235 - Final Exam Study Guide
QUESTION: Through wobble, a single __________ can pair wit more than one __________.
A. codon; anticodon
B. group of three nucleotides in DNA; codon in mRNA
C. tRNA; amino acid
D. Anticodon; codon - ANSWER-D
QUESTION: The increase in number (expansion) of three-nucleotide repeats is responsible for?
A. Sickle-cell anemia
B. Xeroderma pigmentosum
C. Alkaptonuria
D. Trisomy 21
1
, Page 2 of 47
E. Fragile X syndrome
F. None of the above - ANSWER-E
QUESTION: How many copies of the CGG repeat does a normal/unaffected person? (fragile X
syndrome) - ANSWER-Less than 55 (60)
QUESTION: How many copies of the CGG repeat does a premutated individual have? (fragile X
syndrome) - ANSWER-55-230
QUESTION: How many copies of the CGG repeat does an affected individual have? (fragile X
syndrome) - ANSWER-more than 230
QUESTION: Are somatic mutations inherited? - ANSWER-NO (produce patches - basis for
cancers)
QUESTION: Are germ-line mutations inherited? - ANSWER-YES
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QUESTION: Intragenic suppressor mutation - ANSWER-Takes place in the same gene as that
containing the mutation being suppressed (may change a second nucleotide in the SAME codon
altered by the original mutation OR suppress a frameshift mutation with an insertion or
deletion)
QUESTION: Intergenic suppressor mutation - ANSWER-Occurs in a gene other than the one
bearing the original
QUESTION: What causes xeroderma pigmentosum? - ANSWER-Autosomal recessive condition
where people lack nucleotide-excision repair enzymes
QUESTION: The Ames test relies on the rate of a mutation in a bacterium. What is the direction
of this mutation?
A. Auxotrophic bacterial cells turn into prototrophs
B. Prototrophic bacterial cells turn into auxotrophs
C. Heterotrophic organisms turn into phototrophic organism
D. A wild-type bacterium turns into a mutant bacterium
E. A heterozygous organism turns into homozygous one - ANSWER-A (his- to his+)
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QUESTION: A silent mutation is a nucleotide change in the DNA sequence which
A. Does not result in an amino change
B. Converts a sense codon to a non-sense codon
C. Causes a missense mutation, but the altered amino acid has similar characteristics as the
wild-type amino acid, and the altered polypeptide remains functional
D. Causes a missense mutation, and the altered amino acid differs from the wild-type amino
acid, and the altered polypeptide is dysfunctional
E. Results in a frameshift - ANSWER-A
QUESTION: Insertion - ANSWER-Addition of a nucleotide pair
QUESTION: Deletion - ANSWER-Deletion of a nucleotide pair
QUESTION: Frameshift mutations - ANSWER-Changes in the reading frame of a gene (results
from an insertion or a deletion)
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