Question 1

What is nondisjunction?

Accepted Answer

A) failure of sperm and egg to fuse in fertilization 
B) failure of cells to divide by cytokinesis in meiosis 
C) failure of chromosomes to duplicate before mitosis or meiosis 
D) failure of homologous chromosomes or sister chromatids to separate in meiosis 
E) an extra duplication of the chromosomes before mitosis or meiosis 
A) failure of sperm and egg to fuse in fertilization 
B) failure of cells to divide by cytokinesis in meiosis 
C) failure of chromosomes to duplicate before mitosis or meiosis 
D) failure of homologous chromosomes or sister chromatids to separate in meiosis 
E) an extra duplication of the chromosomes before mitosis or meiosis D

Question 2

If a diploid cell from an organism has 46 chromosomes,how many chromosomes are likely to be found in a gamete that is the result of nondisjunction?

Accepted Answer

A) 46 or 92 
B) 23 or 22 
C) 21 or 22 
D) 22 or 24 
E) 24 or 25 
A) 46 or 92 
B) 23 or 22 
C) 21 or 22 
D) 22 or 24 
E) 24 or 25 D

Question 3

A single nondisjunction event results in some gametes with more chromosomes and some gametes with fewer chromosomes.

Accepted Answer

A) True 
 B)False  True

Question 4

A person with the genotype XO is mainly female,phenotypically.A person with the genotype XXY is mainly male.What can you conclude about the Y chromosome?

Accepted Answer

A) It has the same genes as X, just different alleles. 
B) It has the same genes as X, in different orientation. 
C) A Y chromosome confers maleness, regardless of the number of X chromosomes. 
D) The only genes it carries are for female development. 
E) A human cannot survive without a Y chromosome. 
A) It has the same genes as X, just different alleles. 
B) It has the same genes as X, in different orientation. 
C) A Y chromosome confers maleness, regardless of the number of X chromosomes. 
D) The only genes it carries are for female development. 
E) A human cannot survive without a Y chromosome.

Question 5

Refer to the figure below, and then answer the question that follows.
  
-The last members of the Russian Royal Family were executed during the Russian Revolution.Assume the revolution never took place and Alexis,son of Czar Nicholas II and Alexandra,survived and married into the British Royal Family.What is the probability that his children would have hemophilia? What is the probability his children would be carriers for hemophilia?

Accepted Answer

Alexis had hemophilia,which is an X-link

Question 6

Down syndrome in humans is caused by:

Accepted Answer

A) an extra X chromosome. 
B) an extra y chromosome. 
C) three copies of chromosome 21. 
D) three copies of chromosome 13. 
E) a single copy of chromosome 21. 
A) an extra X chromosome. 
B) an extra y chromosome. 
C) three copies of chromosome 21. 
D) three copies of chromosome 13. 
E) a single copy of chromosome 21.

Question 7

What is a recessive disorder?

Accepted Answer

A) a genetic disorder with two functioning alleles 
B) a genetic disorder that will express itself in the presence of one functioning allele 
C) a genetic disorder that will express itself in the presence of two recessive alleles 
D) a genetic disorder that involves change in chromosome number 
E) a genetic disorder that involves change in chromosome structure 
A) a genetic disorder with two functioning alleles 
B) a genetic disorder that will express itself in the presence of one functioning allele 
C) a genetic disorder that will express itself in the presence of two recessive alleles 
D) a genetic disorder that involves change in chromosome number 
E) a genetic disorder that involves change in chromosome structure

Question 8

An autosomal recessive disorder:

Accepted Answer

A) requires that only one parent be a carrier. 
B) displays its symptoms only in heterozygotes. 
C) is more frequent in males than females. 
D) will appear only in children of parents who both carry the gene. 
E) is dominant in females. 
A) requires that only one parent be a carrier. 
B) displays its symptoms only in heterozygotes. 
C) is more frequent in males than females. 
D) will appear only in children of parents who both carry the gene. 
E) is dominant in females.

Question 9

A woman who is a carrier for the hemophilia gene has a child with a man who does not have hemophilia.Which prediction is correct?

Accepted Answer

A) All of the sons and none of the daughters will have hemophilia. 
B) All of the daughters and none of the sons will have hemophilia. 
C) Half of the sons and half of the daughters will have hemophilia. 
D) Half of the sons and none of the daughters will have hemophilia. 
E) Half of the daughters and none of the sons will have hemophilia. 
A) All of the sons and none of the daughters will have hemophilia. 
B) All of the daughters and none of the sons will have hemophilia. 
C) Half of the sons and half of the daughters will have hemophilia. 
D) Half of the sons and none of the daughters will have hemophilia. 
E) Half of the daughters and none of the sons will have hemophilia.

Question 10

The condition in which an organism has more than two sets of chromosomes is called ________,while having either more or fewer than the normal number of a particular chromosome is called ________.

Accepted Answer

polyploidy

Question 11

You have studied the presence of a trait in the members of three generations of a family.With this information,you constructed a ________ to track how the trait was passed down through the generations.

Accepted Answer

The answer of You have studied the presence of a...

Question 12

A trait such as albinism is seen with equal frequency in males and females.Two people who do not have the trait might have offspring who do have the trait,at a frequency of approximately one in four.What can you conclude about the inheritance of this trait?

Accepted Answer

A) recessive, X-linked 
B) recessive, autosomal 
C) recessive, caused by polyploidy 
D) dominant, X-linked 
E) dominant, autosomal 
A) recessive, X-linked 
B) recessive, autosomal 
C) recessive, caused by polyploidy 
D) dominant, X-linked 
E) dominant, autosomal

Question 13

A person with an inherited disorder has children with a person who does not have the condition.Half the children have the disorder,both sons and daughters.How is this condition inherited?

Accepted Answer

A) autosomal dominant 
B) autosomal recessive 
C) X-linked dominant 
D) X-linked recessive 
E) aneuploidy 
A) autosomal dominant 
B) autosomal recessive 
C) X-linked dominant 
D) X-linked recessive 
E) aneuploidy

Question 14

Who is a "carrier" of X-linked disorders,such as hemophilia and color blindness?

Accepted Answer

A) a person who has the X-linked disorder 
B) a heterozygous female who is normal but carries one nonfunctioning allele 
C) a homozygous female who carries the normal alleles 
D) a male who carries the nonfunctioning allele 
E) a male who carries the functioning allele 
A) a person who has the X-linked disorder 
B) a heterozygous female who is normal but carries one nonfunctioning allele 
C) a homozygous female who carries the normal alleles 
D) a male who carries the nonfunctioning allele 
E) a male who carries the functioning allele

Question 15

You are tracking the inheritance of a genetic disorder through a family's pedigree,and you notice that it shows up in every generation.The disorder is most likely:

Accepted Answer

A) recessive. 
B) dominant. 
C) X-linked recessive. 
A) recessive. 
B) dominant. 
C) X-linked recessive.

Question 16

What is the connection between sickle-cell anemia and malaria?

Accepted Answer

A) Both are X-linked. 
B) Both are autosomal recessive. 
C) Both are dominant. 
D) Heterozygotes for malaria have some resistance to sickle-cell anemia. 
E) Heterozygotes for sickle-cell anemia have some resistance to malaria. 
A) Both are X-linked. 
B) Both are autosomal recessive. 
C) Both are dominant. 
D) Heterozygotes for malaria have some resistance to sickle-cell anemia. 
E) Heterozygotes for sickle-cell anemia have some resistance to malaria.

Question 17

Color blindness is caused by an X-linked recessive gene.A color-blind man and a woman with normal vision whose father was color blind have a son.The probability that their son is color blind is:

Accepted Answer

A) 0)25 (or 25 percent). 
B) 0)50 (or 50 percent). 
C) 0)75 (or 75 percent). 
D) 1)00 (or 100 percent). 
E) none of these. 
A) 0)25 (or 25 percent). 
B) 0)50 (or 50 percent). 
C) 0)75 (or 75 percent). 
D) 1)00 (or 100 percent). 
E) none of these.

Question 18

Nondisjunction of the X chromosomes may occur during formation of gametes and produce two kinds of eggs.If normal sperm fertilizes these two kinds of eggs,which of the following pairs of genotypes are possible?

Accepted Answer

A) XX and XY 
B) XXY and XO 
C) XYY and XO 
D) XYY and YO 
A) XX and XY 
B) XXY and XO 
C) XYY and XO 
D) XYY and YO

Question 19

Regarding the human sex chromosomes,which statement is correct?

Accepted Answer

A) The Y chromosome carries a greater number of genes than does the X chromosome. 
B) X and Y are different in size but carry nearly equal numbers of genes. 
C) The X chromosome carries more genes than does the Y chromosome. 
D) The X chromosome carries only gender-related genes. 
E) The X chromosome carries the genes for the development of male phenotype. 
A) The Y chromosome carries a greater number of genes than does the X chromosome. 
B) X and Y are different in size but carry nearly equal numbers of genes. 
C) The X chromosome carries more genes than does the Y chromosome. 
D) The X chromosome carries only gender-related genes. 
E) The X chromosome carries the genes for the development of male phenotype.

Question 20

What is a possible cause of the chromosomal aberration called a "duplication"?

Accepted Answer

A) unequal crossing over 
B) exchange between non-homologous chromosomes 
C) a chromosome fragment that breaks off and does not rejoin any chromosome 
D) breaking of a chromosome fragment, then rejoining in a flipped orientation 
E) nondisjunction 
A) unequal crossing over 
B) exchange between non-homologous chromosomes 
C) a chromosome fragment that breaks off and does not rejoin any chromosome 
D) breaking of a chromosome fragment, then rejoining in a flipped orientation 
E) nondisjunction

Exam 12: Units of Heredity: Chromosomes and Inheritance

What is nondisjunction?

If a diploid cell from an organism has 46 chromosomes,how many chromosomes are likely to be found in a gamete that is the result of nondisjunction?

A single nondisjunction event results in some gametes with more chromosomes and some gametes with fewer chromosomes.

A person with the genotype XO is mainly female,phenotypically.A person with the genotype XXY is mainly male.What can you conclude about the Y chromosome?

Down syndrome in humans is caused by:

What is a recessive disorder?

An autosomal recessive disorder:

A woman who is a carrier for the hemophilia gene has a child with a man who does not have hemophilia.Which prediction is correct?

The condition in which an organism has more than two sets of chromosomes is called ________,while having either more or fewer than the normal number of a particular chromosome is called ________.

You have studied the presence of a trait in the members of three generations of a family.With this information,you constructed a ________ to track how the trait was passed down through the generations.

A trait such as albinism is seen with equal frequency in males and females.Two people who do not have the trait might have offspring who do have the trait,at a frequency of approximately one in four.What can you conclude about the inheritance of this trait?

A person with an inherited disorder has children with a person who does not have the condition.Half the children have the disorder,both sons and daughters.How is this condition inherited?

Who is a "carrier" of X-linked disorders,such as hemophilia and color blindness?

You are tracking the inheritance of a genetic disorder through a family's pedigree,and you notice that it shows up in every generation.The disorder is most likely:

What is the connection between sickle-cell anemia and malaria?

Color blindness is caused by an X-linked recessive gene.A color-blind man and a woman with normal vision whose father was color blind have a son.The probability that their son is color blind is:

Nondisjunction of the X chromosomes may occur during formation of gametes and produce two kinds of eggs.If normal sperm fertilizes these two kinds of eggs,which of the following pairs of genotypes are possible?

Regarding the human sex chromosomes,which statement is correct?

What is a possible cause of the chromosomal aberration called a "duplication"?

Science As a Way of Learning: a Guide to the Natural World

Fundamental Building Blocks: Chemistry, water, and Ph

Lifes Components: Biological Molecules

Lifes Home: the Cell

Lifes Border: the Plasma Membrane

Lifes Mainspring: an Introduction to Energy

Vital Harvest: Deriving Energy From Food

The Green Worlds Gift: Photosynthesis

The Links in Lifes Chain: Genetics and Cell Division

Preparing for Sexual Reproduction: Meiosis

The First Geneticist: Mendel and His Discoveries

Passing on Lifes Information: Dna Structure and Replication

How Proteins Are Made: Genetic Transcription, translation, and Regulation

The Future Isnt What It Used to Be: Biotechnology

An Introduction to Evolution: Charles Darwin, evolutionary Thought, and the Evidence for Evolution

The Means of Evolution: Microevolution

The Outcomes of Evolution: Macroevolution

A Slow Unfolding: the History of Life on Earth

Arriving Late,traveling Far: the Evolution of Human Beings

Viruses,bacteria,archaea,and Protists: the Diversity of Life 1

Fungi: the Diversity of Life 2

Animals: the Diversity of Life 3

Plants: the Diversity of Life 4

The Angiosperms: Form and Function in Flowering Plants

Body Support and Movement: the Integumentary, skeletal, and Muscular Systems

Communication and Control 1: the Nervous System

Communication and Control 2: the Endocrine System

Defending the Body: the Immune System

Transport and Exchange 1: Blood and Breath

Transport and Exchange 2: Digestion, nutrition, and Elimination

An Amazingly Detailed Script: Animal Development

How the Baby Came to Be: Human Reproduction

An Interactive Living World 1: Populations in Ecology

An Interactive Living World 2: Communities in Ecology

An Interactive Living World 3: Ecosystems and Biomes

Filters

The condition in which an organism has more than two sets of chromosomes is called ,while having either more or fewer than the normal number of a particular chromosome is called .