Podcast
Questions and Answers
What is the risk for an affected person who is heterozygous for the dominant allele to pass the trait to their child?
What is the risk for an affected person who is heterozygous for the dominant allele to pass the trait to their child?
- 100%
- 50% (correct)
- 75%
- 25%
What is a characteristic of an autosomal dominant trait?
What is a characteristic of an autosomal dominant trait?
- It is only found in females.
- It skips generations.
- It is expressed regardless of whether the person is homozygous or heterozygous for the dominant allele. (correct)
- It is always recessive.
Which of the following is not a characteristic of autosomal dominant inheritance?
Which of the following is not a characteristic of autosomal dominant inheritance?
- The trait is always recessive. (correct)
- The trait is found in approximate equal distribution between male and female family members.
- The trait has no carrier status.
- The trait appears in every generation.
What is an example of an autosomal dominant trait?
What is an example of an autosomal dominant trait?
What is the risk for an affected person who is homozygous for the dominant allele to pass the trait to their child?
What is the risk for an affected person who is homozygous for the dominant allele to pass the trait to their child?
What happens when a dominant allele is paired with a recessive allele?
What happens when a dominant allele is paired with a recessive allele?
What is a criterion for autosomal dominant patterns of inheritance?
What is a criterion for autosomal dominant patterns of inheritance?
What is an example of a disease that follows an autosomal dominant pattern of inheritance?
What is an example of a disease that follows an autosomal dominant pattern of inheritance?
Study Notes
Autosomal Dominant (AD) Genes
- Autosomal Dominant (AD) single gene traits have controlling gene alleles located on an autosomal chromosome.
- The trait is expressed regardless of whether the person is homozygous or heterozygous for the dominant allele.
- The trait appears in both sexes with equal frequency.
Characteristics of Autosomal Dominant Patterns of Inheritance
- The trait is found in approximate equal distribution between male and female family members.
- The trait has no carrier status (the person with even one dominant allele expresses the trait).
- The trait appears in every generation with clear transmission from parent to child.
- The risk for an affected person who is heterozygous for the dominant allele to pass the trait to their child is 50% with each pregnancy.
- The risk for an affected person who is homozygous for the dominant allele to pass the trait to their child is 100% with each pregnancy.
- Unaffected people do not have the allele and have essentially zero risk for transmitting the trait to their children.
Examples of Autosomal Dominant Disorders
- Familial adenomatous polyposis coli (GIT)
- Hereditary Nonpolyposis Colon Cancer (HNCC)
- Hereditary spherocytosis (Haematology)
- Van Willebrand disease (Haematology)
- Neurofibromatosis (types 1 and 2)
- Huntington disease
- Adult polycystic kidney disease (types 1 and 2)
Autosomal Dominant Single Gene Traits
- Blood type A
- Blood type B
- Free earlobes (not attached to the head)
- Taste sensitivity to phenylthiocarbamide (PTC)
- Widow's peak
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the characteristics of autosomal dominant genes, including their expression, inheritance, and transmission. Learn about the traits controlled by these genes and how they are passed down to offspring.
