Ch 6: Human Genetics

About This Chapter

Watch video lessons on human genetics and learn about population genetics, cancer syndromes, sex determination, heart disease and more. Take the quizzes that follow each lesson to test your knowledge of human genetics.

Human Genetics - Chapter Summary and Learning Objectives

Put simply, human genetics is the study of biological inheritance in people like you and me. How are traits passed on? Why do some people develop genetic disorders? In this chapter, well-informed instructors will answer these questions and more as we look at how genetic research is conducted, aspects of a baby's genetic development, and what causes some significant defects in genes. At the end of this chapter, you'll understand:

  • The purpose of a pedigree in analyzing human genetics, as well as how to construct one
  • Major genetic disorders such as Tay-Sachs disease, hemophilia, Huntington's disease and cancer
  • How a baby's sex is determined
  • The process of prenatal and postnatal genetic testing

VideoObjective
Human Genetics Research Methods: Pedigrees and Population Genetics See how genetics research is conducted with this look into its most basic tool, the pedigree.
Pedigree Analysis in Human Genetics: Tutorial Learn how to read a pedigree and construct one of your own.
Pedigree Analysis in Human Genetics: Inheritance Patterns Discover how genes are passed on over generations and learn how to represent this visually.
Phenotypic Variability in Genetic Disorders: Penetrance and Expressivity Understand the traits of penetrance and expressivity and how they're used to describe genetic variants in humans.
What Is Tay-Sachs Disease? - Symptoms and Genetic Causes Explore Tay-Sachs disease and understand its causes.
Haplosufficient Genes and Inheritance Patterns of Lethal Alleles Learn about the concept of haplosufficiency and see how lethal alleles are retained in the gene pool.
What Is Hemophilia? - Symptoms, Genetic Cause, and Treatment Investigate the science behind this blood disorder.
Huntington's Disease: Symptoms, Genetic Cause, and Treatment Understand the causes and results of this degenerative disease.
Cancer Syndromes: Retinoblastoma Features, Genetic Cause & Treatment Look at certain types of cancer and learn how to treat them.
Sex Determination, X-Inactivation, and Barr Bodies See what causes a baby to be male or female.
Turner Syndrome and Trisomy X: Types of Sex Chromosome Aneuploidy Learn about these disorders that can affect the X chromosome.
Klinefelter and XYY Syndrome: Types of Sex Chromosome Aneuploidy Investigate these genetic disorders that affect males.
How Prenatal and Postnatal Genetic Testing Works See how expecting and new parents can help their babies be healthy with these tests.
Why Heart Disease is a Complex Human Disease Explore the many factors behind heart disease.

17 Lessons in Chapter 6: Human Genetics
Test your knowledge with a 30-question chapter practice test
Human Genetics Research Methods: Pedigrees and Population Genetics

1. Human Genetics Research Methods: Pedigrees and Population Genetics

Have you ever wondered how people study human genetics? Do you know what a pedigree or a complex disease is? In this lesson you'll learn about some of the techniques that human geneticists use and what pedigrees and complex diseases have to do with human genetics.

Pedigree Analysis in Human Genetics: Tutorial

2. Pedigree Analysis in Human Genetics: Tutorial

One of the oldest genetic techniques is pedigree analysis, and yet it is still used every day all around the world by doctors, geneticists, and genetic counselors. Building and reading a pedigree is actually fairly easy if you know what the symbols mean. In fact, it's so easy that you can learn how to do it in less than ten minutes if you watch this video!

Pedigree Analysis in Human Genetics: Inheritance Patterns

3. Pedigree Analysis in Human Genetics: Inheritance Patterns

So you've learned what a pedigree is and how to read or even create one. Now you're ready to learn how to analyze a pedigree and figure out what kind of inheritance pattern a genetic condition follows!

Genetic Disorders: Penetrance & Phenotypic Variability

4. Genetic Disorders: Penetrance & Phenotypic Variability

Did you know that sometimes a dominant human genetic condition will skip a generation in a family? It does happen, and some dominant genetic conditions will also have a wide range of phenotypes, sometimes even within the same family. Learn more in this lesson about phenotypic variability!

What Is Tay-Sachs Disease? - Symptoms and Genetic Cause

5. What Is Tay-Sachs Disease? - Symptoms and Genetic Cause

Tay-Sachs is a devastating genetic disorder that is seen in infants starting when they are only three to six months old. Children who suffer from this disease usually die by the age of four. Learn more about the symptoms and genetic causes of this autosomal recessive disorder.

Haplosufficient Genes and Inheritance Patterns of Lethal Alleles

6. Haplosufficient Genes and Inheritance Patterns of Lethal Alleles

Have you ever wondered why some genetic conditions are recessive while others are dominant? In this lesson, you'll learn about haplosufficiency and how it can sometimes determine whether a genetic condition is dominant or recessive.

What Is Hemophilia? - Symptoms, Genetic Cause & Treatment

7. What Is Hemophilia? - Symptoms, Genetic Cause & Treatment

In this lesson, you'll learn about a group of hereditary bleeding disorders collectively known as hemophilia. You'll learn why afflicted people don't form blood clots and why most hemophiliacs are males.

What Is Huntington's Disease? - Symptoms, Genetic Cause & Treatment

8. What Is Huntington's Disease? - Symptoms, Genetic Cause & Treatment

In this lesson, you'll learn about a neurodegenerative disorder called Huntington's disease. You'll learn what a CAG repeat is, and how the number of these repeats can be used to predict whether or not a person will get Huntington's disease.

Tumor Suppressor Genes: Retinoblastoma Features, Genetic Cause & Treatment

9. Tumor Suppressor Genes: Retinoblastoma Features, Genetic Cause & Treatment

In this lesson, you'll learn about retinoblastoma, which is a rare childhood cancer of the retina. Retinoblastoma is often inherited in an autosomal dominant fashion. Find out why retinoblastoma and other types of hereditary cancers are caused by dominant alleles by watching this lesson.

Cancer Syndromes & Genetic Risk Factors for Cancer

10. Cancer Syndromes & Genetic Risk Factors for Cancer

This lesson describes something called cancer syndrome or family cancer syndrome, as well as the important clues that can help it be detected and two examples of such a condition.

Sex Determination, X-Inactivation, and Barr Bodies

11. Sex Determination, X-Inactivation, and Barr Bodies

Sex determination, X-inactivation and Barr bodies are complex chromosomal processes. Learn more about each of these processes and test your knowledge with a quiz.

Turner Syndrome and Trisomy X: Types of Sex Chromosome Aneuploidy

12. Turner Syndrome and Trisomy X: Types of Sex Chromosome Aneuploidy

Most females have two X chromosomes, which is what makes them women. But what happens when there are more or less than two X chromosomes in a woman's DNA? In this lesson, we'll explore Turner syndrome and Trisomy X.

Klinefelter and XYY Syndrome: Types of Sex Chromosome Aneuploidy

13. Klinefelter and XYY Syndrome: Types of Sex Chromosome Aneuploidy

Most boys and men have two sex chromosomes. But what happens when a male has more than two sex chromosomes? In this lesson, we'll explore two examples of male aneuploidy: Klinefelter Syndrome and XYY Syndrome.

How Prenatal and Postnatal Genetic Testing Works

14. How Prenatal and Postnatal Genetic Testing Works

Have you ever wondered why pregnant women have so many doctor visits and need so many tests done? Learn more about how prenatal and postnatal genetic testing works and test your knowledge with a quiz.

Why Heart Disease is a Complex Human Disease

15. Why Heart Disease is a Complex Human Disease

Many diseases and conditions contribute to heart disease. This makes heart disease very complex and sometimes difficult to treat. Learn more about heart disease and test your knowledge with a quiz.

Gametes: Definition, Formation & Fusion

16. Gametes: Definition, Formation & Fusion

Gametes are the cells that fuse together during sexual reproduction to form a new organism. This lesson covers what these cells are, what they do, and the end result of when they meet.

Genetic Drift: Definition, Examples & Types

17. Genetic Drift: Definition, Examples & Types

Genetic drift reduces genetic variability of a population by decreasing the size of the population. The change in population size and variability often leads to new species and unique populations.

Chapter Practice Exam
Test your knowledge of this chapter with a 30 question practice chapter exam.
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Practice Final Exam
Test your knowledge of the entire course with a 50 question practice final exam.
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