Question 1

Individuals with Lesch-Nyhan syndrome exhibit

Accepted Answer

A) urine that turns black when exposed to air. 
B) compulsive self-mutilation behaviors. 
C) lighter than normal pigmentation of skin,hair,and eyes. 
D) severe anemia. 
E) a cherry-colored spot on the retina. 
A) urine that turns black when exposed to air. 
B) compulsive self-mutilation behaviors. 
C) lighter than normal pigmentation of skin,hair,and eyes. 
D) severe anemia. 
E) a cherry-colored spot on the retina. B

Question 2

What is an inborn error of metabolism? Give an example.

Accepted Answer

An inborn error of metabolism is a genetic disease caused by the absence of a particular enzyme necessary to fulfill a biochemical pathway.An example is alkaptonuria,in which an enzyme necessary for homogentisic acid (HA)metabolism is not made.Therefore,people with this disease cannot metabolize HA and it is excreted in their urine.

Question 3

How can enzyme assay be used to detect carriage of a recessive gene mutation in a person of normal phenotype?

Accepted Answer

If they were a carrier,the person,as a heterozygote,would be expected to produce only half the normal enzyme or protein product for the gene in question.

Question 4

What factor do the diseases PKU,albinism,and alkaptonuria all have in common?

Accepted Answer

They are all marked

Question 5

A person with PKU controls the buildup of phenylpyruvic acid in his or her blood by restricting dietary intake of phenylalanine,thus avoiding the severe symptoms of mental retardation,slow growth rate,and early death.Yet he or she still exhibits the symptoms of fair skin and low adrenaline levels.Why?

Accepted Answer

The PKU mutation is in the gene for phen

Question 6

A person who is homozygous for the gene for hemoglobin A will have sickle-cell disease.

Accepted Answer

A) True 
 B)False

Question 7

Genetic counseling is the best advice that a physician can give a person about his or her risk of having a child with a genetic disorder while lacking precise statistical evidence.

Accepted Answer

A) True 
 B)False

Question 8

The following is a representation of a metabolic pathway that involves genes for enzymes A,B,C,and D: A → B → C → D → product
A mutation in the B gene would result in an accumulation of which gene product?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
A)  A 
B)  B 
C)  C 
D)  D

Question 9

Tay-Sachs disease is most prevalent among populations of the Pennsylvania Amish in the United States.

Accepted Answer

A) True 
 B)False

Question 10

Why did Garrod define alkaptonuria as a recessive genetic disease?

Accepted Answer

A) It is expressed in male members of an affected family. 
B) It is expressed in all members of an affected family. 
C) It is expressed under certain environmental conditions. 
D) It is expressed when two alleles for the disease are present. 
E) It is expressed when one of the two alleles carries the disease trait. 
A) It is expressed in male members of an affected family. 
B) It is expressed in all members of an affected family. 
C) It is expressed under certain environmental conditions. 
D) It is expressed when two alleles for the disease are present. 
E) It is expressed when one of the two alleles carries the disease trait.

Question 11

What does a gene actually code for?

Accepted Answer

A) A polypeptide 
B) An enzyme 
C) An amino acid 
D) A protein 
E) A nucleotide 
A) A polypeptide 
B) An enzyme 
C) An amino acid 
D) A protein 
E) A nucleotide

Question 12

Sickle-cell disease is more common among people who are of African rather than European descent.

Accepted Answer

A) True 
 B)False

Question 13

In a molecule of hemoglobin C,an aspartic acid residue is changed into a ________ residue.

Accepted Answer

A) lysine 
B) tyrosine 
C) leucine 
D) phenylalanine 
E) glutamine 
A) lysine 
B) tyrosine 
C) leucine 
D) phenylalanine 
E) glutamine

Question 14

Cystic fibrosis is a pleiotropic disease.

Accepted Answer

A) True 
 B)False

Question 15

What advantages does chorionic villus sampling have over amniocentesis for fetal analysis of genetic defects?

Accepted Answer

Chorionic villus sampling is generally p

Question 16

Classic albinism is an autosomal recessive mutation.However,two parents with albinism may produce a child with normal pigment.How can this be so?

Accepted Answer

There are a number of biochemical steps

Question 17

A Neurospora mutant that is a tryptophan auxotroph does not need to be grown on a medium that contains tryptophan.

Accepted Answer

A) True 
 B)False

Question 18

Which genetic disease(s)are caused by defective proteins that are not enzymes?

Accepted Answer

A) Tay-Sachs disease and phenylketonuria 
B) Sickle-cell anemia and cystic fibrosis 
C) Lesch-Nyhan syndrome. 
D) Albinism and alkaptonuria 
E) All of these 
A) Tay-Sachs disease and phenylketonuria 
B) Sickle-cell anemia and cystic fibrosis 
C) Lesch-Nyhan syndrome. 
D) Albinism and alkaptonuria 
E) All of these

Question 19

Amniocentesis involves

Accepted Answer

A) prenatal diagnosis of genetic defects in a fetus. 
B) tests for enzyme and protein deficiencies in a fetus. 
C) taking a sample of amniotic fluid with a needle. 
D) analysis for DNA and chromosome defects in a fetus. 
E) All of these 
A) prenatal diagnosis of genetic defects in a fetus. 
B) tests for enzyme and protein deficiencies in a fetus. 
C) taking a sample of amniotic fluid with a needle. 
D) analysis for DNA and chromosome defects in a fetus. 
E) All of these

Question 20

Which of the following statements about phenylketonuria (PKU)is false?

Accepted Answer

A) Buildup of phenylpyruvic acid affects the nervous system. 
B) The amino acid tyrosine cannot be made. 
C) Production of the hormone thyroxin s affected. 
D) The skin color of those with phenylketonuria is light because of decreased levels of melanin. 
E) Adrenalin levels increase in the blood stream. 
A) Buildup of phenylpyruvic acid affects the nervous system. 
B) The amino acid tyrosine cannot be made. 
C) Production of the hormone thyroxin s affected. 
D) The skin color of those with phenylketonuria is light because of decreased levels of melanin. 
E) Adrenalin levels increase in the blood stream.

Exam 4: Gene Function

Individuals with Lesch-Nyhan syndrome exhibit

What is an inborn error of metabolism? Give an example.

How can enzyme assay be used to detect carriage of a recessive gene mutation in a person of normal phenotype?

What factor do the diseases PKU,albinism,and alkaptonuria all have in common?

A person who is homozygous for the gene for hemoglobin A will have sickle-cell disease.

Genetic counseling is the best advice that a physician can give a person about his or her risk of having a child with a genetic disorder while lacking precise statistical evidence.

The following is a representation of a metabolic pathway that involves genes for enzymes A,B,C,and D: A → B → C → D → product A mutation in the B gene would result in an accumulation of which gene product?

Tay-Sachs disease is most prevalent among populations of the Pennsylvania Amish in the United States.

Why did Garrod define alkaptonuria as a recessive genetic disease?

What does a gene actually code for?

Sickle-cell disease is more common among people who are of African rather than European descent.

In a molecule of hemoglobin C,an aspartic acid residue is changed into a ________ residue.

Cystic fibrosis is a pleiotropic disease.

What advantages does chorionic villus sampling have over amniocentesis for fetal analysis of genetic defects?

Classic albinism is an autosomal recessive mutation.However,two parents with albinism may produce a child with normal pigment.How can this be so?

A Neurospora mutant that is a tryptophan auxotroph does not need to be grown on a medium that contains tryptophan.

Which genetic disease(s)are caused by defective proteins that are not enzymes?

Amniocentesis involves

Which of the following statements about phenylketonuria (PKU)is false?

Genetics: An Introduction

DNA: The Genetic Material

DNA Replication

Gene Expression: Transcription

Gene Expression: Translation

Dna Mutation, DNA Repair, and Transposable Elements

Genomics: The Mapping and Sequencing of Genomes

Functional and Comparative Genomics

Recombinant DNA Technology

Mendelian Genetics

Chromosomal Basis of Inheritance

Extensions of and Deviations From Mendelian Genetic Principles

Genetic Mapping in Eukaryotes

Genetics of Bacteria and Bacteriophages

Variations in Chromosome Structure and Number

Regulation of Gene Expression in Bacteria and Bacteriophages

Regulation of Gene Expression in Eukaryotes

Genetic Analysis of Development

Genetics of Cancer

Population Genetics

Quantitative Genetics

Molecular Evolution

Filters