About This Chapter
Basics of Human Genetics - Chapter Summary
This chapter contains several lessons focusing on genetic patterns, disorders and research methodologies. You will study topics such as sex chromosomes, genetic testing, genetic inheritance and genetic variability. Each lesson offers detailed definitions, illustrations and examples to help simplify what might be complex information. After completing your study of this chapter, you should be able to:
- Explain research methods used in the study of human genetics
- Detail information about pedigree analysis
- Identify and define specific genetic disorders and diseases
- Provide details about tumor suppressor genes
- Relate the symptoms of Huntington's Disease, Tay-Sachs Disease and hemophilia
- Understand the workings of postnatal and prenatal genetic testing
- Discuss genetic risk factors for cancer
- Describe types of sex chromosomes
- Explain the complexity of human heart disease
- Define gametes and genetic drift
Experienced instructors have backgrounds in such areas as biology and physical science and make this material easy to understand. Lessons are easily accessible from any device, at any time, and transcripts are printable so you can create helpful reference tools. Take self-assessment quizzes to help you determine how much you know and whether you need further review in any area.
1. Human Genetics Research Methods: Pedigrees and Population Genetics
Human genetics research involves the analysis of pedigrees, or charts of family histories that show the phenotypes and family relationships of individuals. Discover why humans are considered poor model organisms for the study of genetics. Learn about autosomal and sex-linked conditions, multifactorial traits, complex diseases, and human population genetics.
2. Pedigree Analysis in Human Genetics: Tutorial
A pedigree is a chart of family history. Pedigree analysis can be an important process in human genetics. In this tutorial, learn how to create a pedigree and understand proband, gender, and phenotype. Explore the roles of family relationships, multiple births, divorce, death, and miscarriages in expanding and finishing a pedigree analysis.
3. Pedigree Analysis in Human Genetics: Inheritance Patterns
Pedigree analysis can be an important process to find information in human genetics, including inheritance patterns. Review pedigrees, and learn about autosomal dominant, as well as autosomal recessive, inheritance patterns. Explore sex-linked inheritance patterns, both dominate and recessive.
4. Genetic Disorders: Penetrance & Phenotypic Variability
Human genetic conditions are often expressed through a wide range of phenotypes based on how each genotype manifests dominant alleles. Learn about genetic disorders, penetrance, phenotypic variability, expressivity, potential causes of variable expressivity, and autosomal dominant conditions (Retinitis Pigmentosa 11 & Peutz-Jeghers Syndrome).
5. What Is Tay-Sachs Disease? - Symptoms and Genetic Cause
Tay-Sachs disease is a rare genetic disorder that causes progressive neurological deterioration beginning at three to six months of age. Learn more about Tay-Sachs disease, such as the symptoms of the disease and its genetic cause.
6. Haplosufficient Genes and Inheritance Patterns of Lethal Alleles
Haplosufficient genes are crucial in preventing diseases that can affect the normal functions of an individual. Discover the importance of haplosufficency and how haploinsufficiency can result in dominant inheritance patterns of lethal alleles.
7. What Is Hemophilia? - Symptoms, Genetic Cause & Treatment
Different clotting factors can cause blood clots to form incorrectly; this is a bleeding disorder known as hemophilia. Explore more of this disease--including the clotting cascade and clotting factors--and understand the common symptoms and treatments.
8. What Is Huntington's Disease? - Symptoms, Genetic Cause & Treatment
Huntington's disease is an autosomal dominant degenerative neurological disease that progresses slowly but steadily. Discover what is Huntington's disease, the genetic cause, the symptoms, and treatment of the disease.
9. Tumor Suppressor Genes: Retinoblastoma Features, Genetic Cause & Treatment
It is possible for retinoblastoma, a type of eye cancer, to be hereditary, but it also possible to be diagnosed with the condition without any genetic predispositions. Learn about this rare disease's symptoms, causes, and treatments. Discover, too, what the tumor suppressor gene is and its effect on a person's health.
10. Cancer Syndromes & Genetic Risk Factors for Cancer
Cancer syndrome is a condition where genetic mutations that increase the risk of cancer are inherited. Explore what cancer syndrome is and its role in cancer at a young age, discover some clues to help detect if cancer developed due to this condition, and take a look at the genetic risk factors.
11. Sex Determination, X-Inactivation, and Barr Bodies
The determination of the sex of a human occurs at conception. Explore how sex is determined, X-inactivation, and how Barr bodies play a role in sex determination.
12. Turner Syndrome and Trisomy X: Types of Sex Chromosome Aneuploidy
Turner Syndrome and Trisomy X are two types of sex chromosome aneuploidy that occur in females as a result of too few or too many sex chromosomes. Learn about aneuploidy, Turner Syndrome, Trisomy X, and symptoms/treatment options for sex chromosome aneuploidy.
13. Klinefelter and XYY Syndrome: Types of Sex Chromosome Aneuploidy
Klinefelter and XYY Syndrome are two types of sex chromosome aneuploidy that occur in males as a result of possessing more or less than two sex chromosomes. Learn about aneuploidy and two types of sex chromosome aneuploidy, Klinefelter and XYY Syndrome.
14. How Prenatal and Postnatal Genetic Testing Works
Prenatal and postnatal genetic testing works by analyzing the DNA of a fetus during pregnancy and after delivery, which allows doctors to diagnose diseases. Discover examples of genetic tests and the importance of prenatal and postnatal genetic testing.
15. Why Heart Disease is a Complex Human Disease
Complex conditions that impact the functions of the heart are called heart disease. Examine what heart disease is, why it's such a complex disease, and the causes and symptoms of this condition.
16. Gametes: Definition, Formation & Fusion
Cells utilized in sexual reproduction are called gametes. Learn the definition of gametes, the process of how they are formed, and what happens when male and female gametes fuse together.
17. Genetic Drift: Definition, Examples & Types
Genetic drift happens when chance events cause changes in the genetic variations of a population. Examine the definition and learn the types of genetic drift. See examples of population bottlenecking and the founder effect.
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