Question 1

Chemical compounds released during tobacco use can cause ____.

Accepted Answer

A)  sickle-cell anemia 
B)  color blindness 
C)  cancer 
D)  cystic fibrosis 
E)  hemophilia 
A)  sickle-cell anemia 
B)  color blindness 
C)  cancer 
D)  cystic fibrosis 
E)  hemophilia C

Question 2

Turner Syndrome (XO) is the only viable monosomy found in humans. Some sex chromosome trisomies are also viable, including XXX, XXY, and XYY. There are no viable autosomal monosomies, and a small handful of viable autosomal trisomies exist, such as trisomy 21 (Down syndrome), and trisomy 13 and 18, both of which are lethal within the first year of life. Clearly, aneuploidy is not tolerated well in humans. Speculate as to why there are so few viable monosomies (only one) in humans, and why there are so few viable trisomies. Also, speculate as to why aneuploidy involving the sex chromosomes is better tolerated than those involving autosomes.

Accepted Answer

Monosomic cells are missing an entire chromosome. Because only one monosomy is viable, this suggests human cells must require two of each chromosome to function normally. Possibly, some autosomal genes must be present in two copies to achieve adequate expression levels in order to be functional for the cell. Trisomic cells have an extra copy of a chromosome. Due to the low tolerance for human trisomies, human cells seem to require only two copies of each gene, and having three copies of some genes is lethal as there may be too much gene function. The few viable autosomal trisomies are either lethal shortly after birth (trisomy 13 and 18) or have a variety of associated symptoms, including a slightly shortened lifespan (trisomy 21). During human development, all X chromosomes beyond one per cell are inactivated. Therefore, aneuploidy is better tolerated when involving sex chromosomes because there is already a natural process in place for partially "haploidizing" those chromosomes. Despite this, there are symptoms associated with XO, XXY, XYY, and XXX individuals.

Question 3

What is another name for map unit?

Accepted Answer

A)  linkage 
B)  genotype 
C)  locus 
D)  centimorgan 
E)  autosome 
A)  linkage 
B)  genotype 
C)  locus 
D)  centimorgan 
E)  autosome D

Question 4

In Drosophila melanogaster, the gene for eye color is located on the X chromosome. The allele for red eye color (Xw+) is dominant over the allele for white eye color (Xw). You examine a vial of 100 flies that are all offspring from a single genetic cross. You see only red-eyed females present, but you see both red-eyed and white-eyed males present. The genotypes of the parents were ____.

Accepted Answer

A)  Xw+Xw+; Xw+Y 
B)  XwXw; Xw+Y 
C)  Xw+Xw; XwY 
D)  Xw+Xw; Xw+Y 
E)  XwXw; XwY 
A)  Xw+Xw+; Xw+Y 
B)  XwXw; Xw+Y 
C)  Xw+Xw; XwY 
D)  Xw+Xw; Xw+Y 
E)  XwXw; XwY

Question 5

Which statement correctly describes autosomal recessive inheritance?

Accepted Answer

A)  Individuals who are heterozygous for the recessive allele display the trait. 
B)  Individuals who are homozygous for the recessive allele display the trait. 
C)  Individuals who are homozygous for the dominant allele are known as carriers. 
D)  Autosomal alleles are found on the X and Y chromosomes. 
E)  Individuals will never express these traits. 
A)  Individuals who are heterozygous for the recessive allele display the trait. 
B)  Individuals who are homozygous for the recessive allele display the trait. 
C)  Individuals who are homozygous for the dominant allele are known as carriers. 
D)  Autosomal alleles are found on the X and Y chromosomes. 
E)  Individuals will never express these traits.

Question 6

You are genetic counselor, and a couple comes to you with concerns that if they have a child together, he or she could have sickle-cell anemia. Genetic tests reveal that both the man and woman are carriers for sickle-cell anemia. How should you advise them?

Accepted Answer

A)  Half of their children will have sickle-cell anemia, and the other half will be carriers. 
B)  All of their children will have sickle-cell anemia. 
C)  There are no concerns, because none of their offspring have a chance of inheriting the sickle-cell allele. 
D)  While none of their children will have sickle-cell anemia, each child will have a 50% chance of being a carrier. 
E)  Each of their children will have a 25% chance of having sickle-cell anemia. 
A)  Half of their children will have sickle-cell anemia, and the other half will be carriers. 
B)  All of their children will have sickle-cell anemia. 
C)  There are no concerns, because none of their offspring have a chance of inheriting the sickle-cell allele. 
D)  While none of their children will have sickle-cell anemia, each child will have a 50% chance of being a carrier. 
E)  Each of their children will have a 25% chance of having sickle-cell anemia.

Question 7

During normal human embryonic development, if ____, then the SRY gene switches development toward ____.

Accepted Answer

A)  a Y chromosome is present; maleness 
B)  an X chromosome is present; femaleness 
C)  two X chromosomes are present; femaleness 
D)  the X chromosome is absent; maleness 
E)  a Y chromosome is present; femaleness 
A)  a Y chromosome is present; maleness 
B)  an X chromosome is present; femaleness 
C)  two X chromosomes are present; femaleness 
D)  the X chromosome is absent; maleness 
E)  a Y chromosome is present; femaleness

Question 8

Cytoplasmic inheritance refers to genes found in ____.

Accepted Answer

A)  sex chromosomes 
B)  mitochondria and chloroplasts 
C)  viruses 
D)  bacteria 
E)  linkages 
A)  sex chromosomes 
B)  mitochondria and chloroplasts 
C)  viruses 
D)  bacteria 
E)  linkages

Question 9

For most multicellular eukaryotes, including humans, mitochondria are inherited ____.

Accepted Answer

A)  only from the father 
B)  from both the father and the mother 
C)  from the mother for female offspring and from the father for male offspring 
D)  randomly from either the father or the mother 
E)  only from the mother 
A)  only from the father 
B)  from both the father and the mother 
C)  from the mother for female offspring and from the father for male offspring 
D)  randomly from either the father or the mother 
E)  only from the mother

Question 10

Sex-linked genes are ____.

Accepted Answer

A)  expressed differently based on the sex of an individual 
B)  linked to the SRY sex-determining gene 
C)  located on sex chromosomes 
D)  determinants of the sex of an individual 
E)  found exclusively in one sex or the other 
A)  expressed differently based on the sex of an individual 
B)  linked to the SRY sex-determining gene 
C)  located on sex chromosomes 
D)  determinants of the sex of an individual 
E)  found exclusively in one sex or the other

Question 11

Explain the difference in meiotic products that arise when nondisjunction occurs during the first meiotic division versus those that arise when nondisjunction occurs during the second meiotic division.

Accepted Answer

If nondisjunction occurs during the firs

Question 12

When two genes are located on different chromosomes, ____ of the offspring from a testcross for genetic linkage should have a recombinant phenotype.

Accepted Answer

A)  over 75% 
B)  about 50% 
C)  about 25% 
D)  about 10% 
E)  about 5% 
A)  over 75% 
B)  about 50% 
C)  about 25% 
D)  about 10% 
E)  about 5%

Question 13

Which process results in the production of offspring who are recombinant for two genes on the same chromosome?

Accepted Answer

A)  movement of transposable elements 
B)  pairing of nonhomologous chromosomes 
C)  gene duplication 
D)  exon shuffling 
E)  crossing over between homologous chromosomes 
A)  movement of transposable elements 
B)  pairing of nonhomologous chromosomes 
C)  gene duplication 
D)  exon shuffling 
E)  crossing over between homologous chromosomes

Question 14

In humans, a deletion from chromosome 5 typically leads to severe mental retardation and a malformed larynx; this disorder is known as ____.

Accepted Answer

A)  Turner syndrome 
B)  Down syndrome 
C)  cri-du-chat 
D)  Triple-X syndrome 
E)  Klinefelter syndrome 
A)  Turner syndrome 
B)  Down syndrome 
C)  cri-du-chat 
D)  Triple-X syndrome 
E)  Klinefelter syndrome

Question 15

An individual who is a carrier of a genetically inherited disease ____.

Accepted Answer

A)  has the disease, and all of their offspring will have the disease 
B)  does not have the disease, but must have a parent with the disease 
C)  does not have the disease, but may have offspring with the disease 
D)  has the disease and must have a parent with the disease 
E)  does not have the disease, but must have a parent with the disease and may have offspring with the disease 
A)  has the disease, and all of their offspring will have the disease 
B)  does not have the disease, but must have a parent with the disease 
C)  does not have the disease, but may have offspring with the disease 
D)  has the disease and must have a parent with the disease 
E)  does not have the disease, but must have a parent with the disease and may have offspring with the disease

Question 16

If you see a male calico cat, you can be fairly certain that his diploid cells have a sex chromosome combination of ____.

Accepted Answer

A)  XYY 
B)  XY 
C)  XX 
D)  XXY 
E)  XO 
A)  XYY 
B)  XY 
C)  XX 
D)  XXY 
E)  XO

Question 17

You are a genetic counselor, and a couple comes to you with concerns that if they have a child together, he or she could have cystic fibrosis. Genetic tests reveal that the woman is a carrier for cystic fibrosis, but the man is not. How should you advise them?

Accepted Answer

A)  Half of their children will have cystic fibrosis, and the other half will be carriers. 
B)  All of their children will have cystic fibrosis. 
C)  There are no concerns, because none of their offspring have a chance of inheriting the cystic fibrosis allele. 
D)  While none of their children will have cystic fibrosis, each child will have a 50% chance of being a carrier. 
E)  All of their children will have a 25% chance of having cystic fibrosis. 
A)  Half of their children will have cystic fibrosis, and the other half will be carriers. 
B)  All of their children will have cystic fibrosis. 
C)  There are no concerns, because none of their offspring have a chance of inheriting the cystic fibrosis allele. 
D)  While none of their children will have cystic fibrosis, each child will have a 50% chance of being a carrier. 
E)  All of their children will have a 25% chance of having cystic fibrosis.

Question 18

A mutation in the human gene for a fibroblast growth factor receptor (FGFR) appears to be responsible for ____.

Accepted Answer

A)  Duchenne muscular dystrophy 
B)  phenylketonuria 
C)  achondroplasia 
D)  sickle-cell anemia 
E)  cystic fibrosis 
A)  Duchenne muscular dystrophy 
B)  phenylketonuria 
C)  achondroplasia 
D)  sickle-cell anemia 
E)  cystic fibrosis

Question 19

Figure 13.5a
Which genetic condition is revealed in the karyotype display shown in the accompanying figure?

Accepted Answer

A)  Turner syndrome 
B)  Down syndrome 
C)  cri-du-chat 
D)  Triple-X syndrome 
E)  Klinefelter syndrome 
A)  Turner syndrome 
B)  Down syndrome 
C)  cri-du-chat 
D)  Triple-X syndrome 
E)  Klinefelter syndrome

Question 20

Linked genes are ____.

Accepted Answer

A)  genes whose effects combine to influence a single characteristic 
B)  different alleles of the same gene 
C)  genes that affect two different traits and lead to a 9:3:3:1 phenotype ratio in a dihybrid cross 
D)  genes that do not sort independently because they are physically near each other on the same chromosome 
E)  genes on two different chromosomes 
A)  genes whose effects combine to influence a single characteristic 
B)  different alleles of the same gene 
C)  genes that affect two different traits and lead to a 9:3:3:1 phenotype ratio in a dihybrid cross 
D)  genes that do not sort independently because they are physically near each other on the same chromosome 
E)  genes on two different chromosomes

Exam 13: Genes, Chromosomes, and Human Genetics

Chemical compounds released during tobacco use can cause ____.

What is another name for map unit?

Which statement correctly describes autosomal recessive inheritance?

You are genetic counselor, and a couple comes to you with concerns that if they have a child together, he or she could have sickle-cell anemia. Genetic tests reveal that both the man and woman are carriers for sickle-cell anemia. How should you advise them?

During normal human embryonic development, if ____, then the SRY gene switches development toward ____.

Cytoplasmic inheritance refers to genes found in ____.

For most multicellular eukaryotes, including humans, mitochondria are inherited ____.

Sex-linked genes are ____.

Explain the difference in meiotic products that arise when nondisjunction occurs during the first meiotic division versus those that arise when nondisjunction occurs during the second meiotic division.

When two genes are located on different chromosomes, ____ of the offspring from a testcross for genetic linkage should have a recombinant phenotype.

Which process results in the production of offspring who are recombinant for two genes on the same chromosome?

In humans, a deletion from chromosome 5 typically leads to severe mental retardation and a malformed larynx; this disorder is known as ____.

An individual who is a carrier of a genetically inherited disease ____.

If you see a male calico cat, you can be fairly certain that his diploid cells have a sex chromosome combination of ____.

You are a genetic counselor, and a couple comes to you with concerns that if they have a child together, he or she could have cystic fibrosis. Genetic tests reveal that the woman is a carrier for cystic fibrosis, but the man is not. How should you advise them?

A mutation in the human gene for a fibroblast growth factor receptor (FGFR) appears to be responsible for ____.

Figure 13.5a Which genetic condition is revealed in the karyotype display shown in the accompanying figure?

Linked genes are ____.

Introduction to Biological Concepts and Research

Life, Chemistry, and Water

Biological Molecules: the Carbon Compounds of Life

Cells

Membranes and Transport

Energy, Enzymes, and Biological Reactions

Cellular Respiration: Harvesting Chemical Energy

Photosynthesis

Cell Communication

Cell Division and Mitosis

Meiosis: the Cellular Basis of Sexual Reproduction

Mendel, Genes, and Inheritance

Dna Structure, Replication, and Organization

Gene Expression: From Dna to Protein

Regulation of Gene Expression

Bacterial and Viral Genetics

Dna Technology: Making and Using Genetically Altered Organisms, and Other Applications

Genomes and Proteomes

The Development of Evolutionary Thought

Microevolution: Genetic Changes Within Populations

Speciation

Paleobiology and Macroevolution

Systematic Biology: Phylogeny and Classification

The Origin of Life

Prokaryotes and Viruses

Protists

Seedless Plants

Seed Plants

Fungi

Animal Phylogeny, Acoelomates, and Protostomes

Deuterostomes: Vertebrates and Their Closest Relatives

The Plant Body

Transport in Plants

Plant Nutrition

Reproduction and Development in Flowering Plants

Plant Signals and Responses to the Environment

Introduction to Animal Organization and Physiology

Information Flow and the Neuron

Nervous Systems

Sensory Systems

The Endocrine System

Muscles, Bones, and Body Movements

The Circulatory System

Defenses Against Disease

Gas Exchange: the Respiratory System

Digestive Systems and Animal Nutrition

Regulating the Internal Environment: Osmoregulation, Excretion, and Thermoregulation

Animal Reproduction

Animal Development

Ecology and the Biosphere

Population Ecology

Population Interactions and Community Ecology

Ecosystems

Biodiversity and Conservation Biology

Animal Behavior

Filters

During normal human embryonic development, if , then the SRY gene switches development toward .