lesson 3 2/23/12 heredity & genetics name a few traits that you inherited from a family member?...

Lesson Lesson 33

2/23/12 Heredity & Genetics

Name a few traits that you inherited from a family member?

What family member did you inherit the trait from?

Lesson Lesson 33Family members often share a strong physical

resemblance.

What inherited characteristics are visible in this family?

Heredity and Genetics

Lesson Lesson 33In this lesson, you will learn to:

• Examine genetics and its role in fetal development

• Identify common genetic disorders

• Analyze genetic research and technology and their impact on the health of people with genetic disorders

Lesson Objectives

Lesson Lesson 33Inheriting Traits

• No two individuals are exactly alike. Even identical twins have some differences.

• Heredity is a significant factor that influences the way an individual develops.

• Some traits that you inherit from your parents are your eye and hair color.

• Environment can also influence inherited traits.

Heredity

Lesson Lesson 33Chromosomes and Genes

• Most cells of your body contain a nucleus—the cell’s control center.

• Inside each nucleus is a set of chromosomes.

• Most cells in the body contain 46 chromosomes arranged as 23 pairs.

• Sections of chromosomes, called genes, carry codes for specific traits.

• Like chromosomes, genes occur in pairs. One gene from each pair is inherited from each parent.

Heredity

Lesson Lesson 33DNA

• All living things are made of DNA.

• Chemical compounds, called bases, make up the structure of DNA.

• The order of the bases is called the genetic code. Cells use the genetic code to make proteins.

• Unless you have an identical twin, your DNA is different from that of any other person.

Heredity

Lesson Lesson 33

Lesson Lesson 33Dominant and Recessive Genes

• At least one pair of genes is responsible for each human trait.

• Some genes are dominant, and others are recessive. The traits of dominant genes generally appear in offspring whenever they are present.

• The traits of recessive genes usually appear only when dominant genes are not present.

Genetics and Fetal Development

Lesson Lesson 33

Lesson Lesson 33Genes and Gender

• In humans, one pair of chromosomes determines the gender of an individual.

• If you are female, these two chromosomes look exactly alike and are called X chromosomes.

• If you are male, the two chromosomes differ—one is shorter than the other and is called a Y chromosome.


Lesson Lesson 33Genetic Makeup

• Sperm contain an X or a Y chromosome. Eggs have only an X chromosome.

• The gender of a child is determined by which type of sperm—X or Y—unites with an egg.


Lesson Lesson 33Mutation

• Sometimes the genes that an individual inherits contain a mutation, or abnormality, in the base sequence of the genetic code.

• Often the mutation has little or no effect on the individual, but sometimes the mutation can result in defects or other health problems.

• Some genetic disorders, such as those that cause birth defects, are apparent right away.

Genetic Disorders

Lesson Lesson 33Common Human Genetic Disorders

Genetic Disorders

Down Syndrome Video

Lesson Lesson 33Test for Genetic Disorders

Two common technologies used to test for genetic disorders are:

1. Amniocentesis

2. Chorionic villi sampling (CVS)

Genetic Disorders

Lesson Lesson 33Genetic Counseling

• Research for diagnosing, preventing, and treating genetically related diseases has resulted in a wide variety of programs.

• Genetic counselors can advise families about the probability of having a child with a genetically related disease.

• They also can guide families of children with genetic disorders about possible treatment options.

Genetic Disorders

Lesson Lesson 33Gene Therapy

• When the defective gene is replaced with a normal one using

the gene therapy, the cells with the new gene begin to make the missing substance.

• The practice of placing fragments of DNA from one organism into another is called genetic engineering, and it is

considered highly experimental.

• Genetic diseases for which scientists are researching gene therapies include cystic fibrosis and various types of cancer.

Genetic Research to Cure Disease

Lesson Lesson 33Genetically Engineered Drugs

• Genes used to treat disease aren’t usually inserted directly into human beings.

• Instead they are placed into other organisms, causing them to produce substances that can be used to treat human diseases and disorders.

• Genetically produced medicines include treatments for burns and ulcers, growth defects, and ovarian and breast cancers.

• Factor VIII medicines treat hemophilia. Genetic engineering also is used to produce some vaccines that prevent diseases.


Lesson Lesson 33

1. heredity

2. DNA

3. genes

4. genetic disorder

Quick Review

Q. The passing of traits from parents to their children is called _________.

Choose the appropriate option.

Lesson Lesson 33

A. 1. heredity

The passing of traits from parents to their children is called heredity.

Click Next to attempt another question.

Quick Review - Answer

Lesson Lesson 33Quick Review

1. Sickle-cell anemia

2. Cirrhosis

3. Cystic fibrosis

4. Tay-Sachs disease


Q. Which of the following is not a genetic disorder?

Lesson Lesson 33



A. 2. cirrhosis

Genetic disorders do not include cirrhosis.

Lesson Lesson 33Quick Review

Q. Amniocentesis is a procedure in which a syringe is inserted through a pregnant female’s abdominal wall and into the amniotic fluid surrounding the developing fetus.

True

False


Lesson Lesson 33

A. True. Amniocentesis is a procedure in which a syringe is

inserted through a pregnant female’s abdominal wall and into the amniotic fluid surrounding the developing fetus.



Lesson Lesson 33

Q. Fetal development is the making of a new and unique human being. Genetics play only a marginal role in the development of the fetus.

True

False

Quick Review


Lesson Lesson 33

A. False. Fetal development is the making of a new and

unique human being. Genetics play an important role in the development of the fetus.



Lesson Lesson 33

End of Lesson 3

Click Home to view the Main menu.

Lesson Lesson 33

A. Correct! The passing of traits from parents to their

children is called heredity.



Lesson Lesson 33

You have answered the question incorrectly. Go back to try again, or click Next to view the correct answer.


Lesson Lesson 33

• No two individuals are exactly alike. Even identical twins have some differences.

• Heredity is a significant factor that influences the way an individual develops.

• Some traits that you inherit from your parents are your eye and hair color.

• Environment can also influence inherited traits.

Inheriting Traits

Heredity is the passing of traits that are biological from parents to their children.

Heredity is the passing of traits that are biological from parents to their children.

Heredity

Lesson Lesson 33






Chromosomes and Genes

A chromosome is a threadlike structure found within the nucleus of a cell that carries the code for inherited traits.

A chromosome is a threadlike structure found within the nucleus of a cell that carries the code for inherited traits.

Heredity

Lesson Lesson 33






Chromosomes and Genes

A gene is the basic unit of heredity.

A gene is the basic unit of heredity.

Heredity

Lesson Lesson 33DNA

• All living things are made of DNA.

• Chemical compounds, called bases, make up the structure of DNA.

• The order of the bases is called the genetic code. Cells use the genetic code to make proteins.

• Unless you have an identical twin, your DNA is different from that of any other person.

DNA, or deoxyribonucleic acid, is the chemical unit that makes up chromosomes.

DNA, or deoxyribonucleic acid, is the chemical unit that makes up chromosomes.

Heredity

Lesson Lesson 33

• Sometimes the genes that an individual inherits contain a mutation, or abnormality, in the base sequence of the genetic code.

• Often the mutation has little or no effect on the individual, but sometimes the mutation can result in defects or other health problems.

• Some genetic disorders, such as those that cause birth defects, are apparent right away.

Mutation

A genetic disorder is a disorder caused partly or completely by a defect in genes.

A genetic disorder is a disorder caused partly or completely by a defect in genes.

Genetic Disorders

Lesson Lesson 33


1. Amniocentesis


Test for Genetic Disorders

Genetic Disorders

Amniocentesis is a procedure in which a syringe is inserted through a pregnant female’s abdominal wall into the amniotic fluid surrounding the developing fetus.

Amniocentesis is a procedure in which a syringe is inserted through a pregnant female’s abdominal wall into the amniotic fluid surrounding the developing fetus.

Lesson Lesson 33


1. Amniocentesis


Test for Genetic Disorders

Genetic Disorders

Chorionic villi sampling (CVS) is a procedure in which a small piece of membrane is removed from the chorion, a layer of tissue that develops into the placenta.

Chorionic villi sampling (CVS) is a procedure in which a small piece of membrane is removed from the chorion, a layer of tissue that develops into the placenta.

Lesson Lesson 33Gene Therapy

• When the defective gene is replaced with a normal one using the gene therapy, the cells with the new gene begin to make the missing substance.

• The practice of placing fragments of DNA from one organism into another is called genetic engineering, and it is

considered highly experimental.

• Genetic diseases for which scientists are researching gene therapies include cystic fibrosis and various types of cancer.

Gene therapy is the process of inserting normal genes into human cells to correct genetic disorders.

Gene therapy is the process of inserting normal genes into human cells to correct genetic disorders.


Lesson Lesson 33

A. Correct! Genetic disorders do not include the following:

cirrhosis.



Lesson Lesson 33



Lesson Lesson 33

A. Correct! Amniocentesis is a procedure in which a

syringe is inserted through a pregnant female’s abdominal wall and into the amniotic fluid surrounding the developing fetus.



Lesson Lesson 33



Lesson Lesson 33

A. Correct! Fetal development is the making of a new and

unique human being. Genetics play an important role in the development of the fetus.



Lesson Lesson 33



lesson 3 2/23/12 heredity & genetics name a few traits that you inherited from a family member?...

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