Pedigrees Flashcards
(23 cards)
What is a pedigree?
A diagram of family relationships that uses symbols for people and lines for genetic relationships.
What do horizontal lines in a pedigree represent?
Mating.
What do vertical lines in a pedigree represent?
Offspring.
What does shading in a pedigree indicate?
Trait of interest.
What is the significance of knowing the position of a gene?
It helps determine if the gene for a trait is on an autosome or a sex chromosome.
What are the four possible modes of inheritance (MOI)?
- Autosomal Recessive
- Autosomal Dominant
- X-Linked Recessive
- X-Linked Dominant
What is an example of an Autosomal Recessive trait?
Cystic fibrosis.
What is an example of an Autosomal Dominant trait?
Retinoblastoma.
What is an example of an X-Linked Recessive trait?
Duchenne Muscular Dystrophy.
What is an example of an X-Linked Dominant trait?
Rett Syndrome.
True or False: Some pedigrees may have more than one mode of inheritance.
True.
In pedigree analysis, what should you always include?
A legend to explain your labeling choices.
Fill in the blank: Autosomal traits are passed on from parents to offspring _____ of the X and Y Chromosomes.
independent
What does an obligate heterozygote refer to?
An individual that must carry one dominant and one recessive allele.
What is a key characteristic of male-to-male transmission in inheritance?
It indicates Autosomal inheritance.
What does the presence of a trait in every generation suggest about its inheritance?
It indicates Dominance.
What does the skipping of generations in a pedigree suggest?
It indicates Recessive inheritance.
What is the normal genotype for a female with an X-Linked Dominant trait?
X^A-X^A or X^A-Y.
What is the affected genotype for a male with an X-Linked Recessive trait?
X^A-Y.
What is the normal genotype for an Autosomal Recessive trait?
A^+A^+ or A^+A^-.
What is the affected genotype for an Autosomal Recessive trait?
A^-A^-.
What does the term ‘inbreeding’ refer to?
Consanguinity or sharing blood.
Why is it important to analyze more generations in a pedigree?
To gather more information needed to decide the correct mode of inheritance.
