Chapter 24: Genetics and Genomics

I. The Emerging Role of Genetics and Genomics in Medicine

A. Genetics is____________________________________________________________

B. Genes are_____________________________________________________________

C. Genes are part of structures called _________________________________________

D. A gene’s nucleotide sequence tells a cell____________________________________

________________________________________________________________________

E. A genome is___________________________________________________________

F. Somatic cells have______________________________________________________

G. Diploid means_________________________________________________________

H. Sex cells have_________________________________________________________

I. Haploid means_________________________________________________________

J. Genomics is____________________________________________________________

K. Proteonomics focuses on_________________________________________________

________________________________________________________________________

L. Environmental factors that affect how genes are expressed are___________________

________________________________________________________________________

II. Modes of Inheritance

A. Introduction

1. The probability that a certain trait will occur in the offspring of two individuals

can be determined by________________________________________________

__________________________________________________________________

B. Chromosomes and Genes Come in Pairs

1. Karyotypes are___________________________________________________

__________________________________________________________________

2. Autosomes are___________________________________________________

3. Sex chromosomes are______________________________________________

__________________________________________________________________

4. Most chromosomes contain____________________________________ genes.

5. Alleles are_______________________________________________________

6. Homozygous alleles are____________________________________________

7. Heterozygous alleles are____________________________________________

8. Genotype is_____________________________________________________

9. Phenotype is_____________________________________________________

10. A wild type allele is______________________________________________

11. A mutant allele is________________________________________________

C. Dominant and Recessive Inheritance

1. A dominant allele is_______________________________________________

2. A recessive allele is________________________________________________

__________________________________________________________________

3. An autosomal gene is located________________________________________

4. An X-linked gene is located_________________________________________

5. A Y-linked gene is located__________________________________________

6. Mode of inheritance refers to________________________________________

__________________________________________________________________

7. An autosomal condition is equally likely to affect________________________

8. X-linked characteristics affect_______________________________________

9. Recessive conditions can skip a generation because______________________

__________________________________________________________________

10. Dominant conditions do not skip generations because___________________

__________________________________________________________________

11. The disease_____________________________ is an example of an autosomal

recessive disorder.

12. If both parents are heterozygotes for the trait that causes cystic fibrosis, there

is a_________________ chance that their offspring will be homozygous dominant,

a______________________________ chance their offspring will be heterozygous,

and a___________________ chance their offspring will be homozygous recessive.

13. A Punnet square is_______________________________________________

__________________________________________________________________

14. A pedigree is___________________________________________________

__________________________________________________________________

15. An example of an autosomal dominant disorder is______________________

__________________________________________________________________

D. Different Dominance Relationships

1. Incomplete dominance is___________________________________________

__________________________________________________________________

2. An example of a trait inherited through incomplete dominance is___________

__________________________________________________________________

3. Codominant means________________________________________________

__________________________________________________________________

4. The genotypes of individuals with the following blood types are:

type A

type B

type AB

type O

III. Gene Expression

A. Introduction

1. The same allele combination can produce different phenotypes because______

__________________________________________________________________

2. A major goal of genomics is_________________________________________

__________________________________________________________________

B. Penetrance and Expressivity

1. Completely penetrant means________________________________________

__________________________________________________________________

2. Incompletely penetrant means_______________________________________

__________________________________________________________________

3. A phenotype is variably expressive if__________________________________

__________________________________________________________________

C. Pleiotropy

1. Pleiotropy is_____________________________________________________

__________________________________________________________________

2. An example of a disease that exhibits pleiotropy is_______________________

D. Genetic Heterogeneity

1. Genetic heterogeneity is____________________________________________

__________________________________________________________________

2. An example of a condition that exhibits genetic heterogeneity is____________

__________________________________________________________________

IV. Complex Traits

A. Polygenic means_______________________________________________________

B. Variations in height are due to____________________________________________

________________________________________________________________________

C. Variations in skin color are due to__________________________________________

________________________________________________________________________

D. Variations in eye color are due to__________________________________________

________________________________________________________________________

E. Multifactorial traits are__________________________________________________

F. Examples of complex traits are____________________________________________

V. Matters of Sex

A. Introduction

1. A human female is termed homogametic because________________________

__________________________________________________________________

2. A human male is termed heterogametic because_________________________

__________________________________________________________________

B. Sex Determination

1. A male is conceived when__________________________________________

__________________________________________________________________

2. A female is conceived when________________________________________

__________________________________________________________________

3. The gene responsible for being male is_________________________________

C. Sex Chromosomes and Their Genes

1. The X chromosome has_______________________________________ genes.

2. The Y chromosome has_______________________________________ genes.

3. The three groups of Y-linked genes are________________________________

__________________________________________________________________

__________________________________________________________________

4. Y-linked genes are transmitted from father to___________________________

5. Any gene on the X chromosome of a male is expressed in his phenotype because

__________________________________________________________________

6. An allele on an X chromosome of a female may or may not be expressed because

__________________________________________________________________

__________________________________________________________________

7. The male is said to be hemizygous for X-linked traits because______________

__________________________________________________________________

8. Examples of X-linked recessive traits are______________________________

__________________________________________________________________

9. If a mother is heterozygous for a particular X-linked gene, her son has a______

________________________________ chance of inheriting either allele from her.

10. X-linked genes are passed on from__________________________________

11. A daughter can inherit an X-linked disorder only if______________________

__________________________________________________________________

D. Gender Effects and Phenotypes

1. A sex-linked trait is_______________________________________________

__________________________________________________________________

2. Sex-influenced inheritance is________________________________________

__________________________________________________________________

3. A heterozygous male is bald and a heterozygous female is not bald because___

__________________________________________________________________

4. Genomic imprinting is_____________________________________________

__________________________________________________________________

VII. Chromosome Disorders

A. Polyploidy

1. Polyploidy is_____________________________________________________

__________________________________________________________________

2. Polyploidy results from____________________________________________

__________________________________________________________________

3. The fate of a polyploid human is_____________________________________

B. Aneuploidy

1. Aneuploid means_________________________________________________

2. Euploid means___________________________________________________

3. Anueploidy results from____________________________________________

4. Nondisjunction is_________________________________________________

__________________________________________________________________

5. Autosomal aneuploidy often results in_________________________________

__________________________________________________________________

5. Trisomy is_______________________________________________________

6. Monosomy is____________________________________________________

7. Translocation is___________________________________________________

__________________________________________________________________

8. Trisomy 21 is known as____________________________________________

9. Other common autosomal trisomies are________________________________

10. Turner syndrome results from______________________________________

11. Klinefelter syndrome results from___________________________________

12. Jacobs syndrome results from______________________________________

C. Prenatal Tests

1. An ultrasound can detect___________________________________________

__________________________________________________________________

__________________________________________________________________

2. Maternal serum markers can detect___________________________________

__________________________________________________________________

3. Amniocentesis is__________________________________________________

_______________________________________________________________and

it can detect________________________________________________________

4. Chorionic villus sampling is_________________________________________

_______________________________________________________________and

it can detect________________________________________________________

5. Fetal cell sorting is_____________________________________________ and

it can detect________________________________________________________

VIII. Gene Therapy

A. Introduction

1. Functions of gene therapy are_______________________________________

__________________________________________________________________

2. Gene therapy operates at___________________________________________

B. Two Approaches to Gene Therapy

1. Two types of gene therapy are_______________________________________

__________________________________________________________________

2. Heritable gene therapy is___________________________________________

__________________________________________________________________

3. Heritable gene therapy is most commonly performed in___________________

4. Nonheritable gene therapy is________________________________________

__________________________________________________________________

5. A nonheritable gene therapy for cystic fibrosis is________________________

__________________________________________________________________

C. Gene Therapy Targets

1. Introduction

a. Some methods used to introduce therapeutic genes into cells include the

use of_______________________________________________________

____________________________________________________________

b. The challenge in nonheritable gene therapy is_____________________

____________________________________________________________

2. Bone Marrow

a. Bone marrow tissue includes__________________________________

b. Many gene therapy targets might be reached by bone marrow because

____________________________________________________________

____________________________________________________________

3. Skin

a. In the laboratory, skin cells grow_______________________________

b. Skin grafts can be used to____________________________________

____________________________________________________________

4. Muscle

a. The reasons muscle tissue is a good target for gene therapy are_______

____________________________________________________________

____________________________________________________________

b. A challenge with muscle is____________________________________

____________________________________________________________

5. Endothelium

a. Endothelium is_____________________________________________

b. Endothelium can be altered to_________________________________

____________________________________________________________

6. Liver

a. The liver controls___________________________________________

____________________________________________________________

b. Liver cells that are genetically altered can relieve__________________

____________________________________________________________

7. Lungs

a. An aerosol can directly reach respiratory tube lining cells___________

____________________________________________________________

____________________________________________________________

b. A form of gene therapy used to treat emphysema is________________

____________________________________________________________

8. Nerve Tissue

a. Gene therapy of neurons is not feasible because___________________

____________________________________________________________

b. Routes of nerve cell gene therapy could include___________________

____________________________________________________________

D. Genomics and a New View of Anatomy and Physiology

1. Today, human genetics and genomics have shifted focus_____________________

as well as conditions molded by interactions among __________________________

_________________________________________________________________.

2. Physiology is not only being dissected at _______________________________,

but at the level of ___________________________________________________

_________________________________________________________________.