Lect 29 Flashcards
What is a Pedigree?
A diagram of family relationships
Pedigrees are often used in genetics to track inheritance patterns.
Describe the rules of making a pedigree
What does a pedigree showing breast cancer in a mother and grandmother suggest?
A hereditary link, likely involving the BRCA1 gene.
This indicates a potential genetic predisposition to breast cancer.
What is the impact of the BRCA1 gene mutation?
Increases the risk of breast cancer.
The BRCA1 gene is associated with a higher likelihood of developing breast cancer when mutated.
What type of inheritance pattern does the BRCA1 gene mutation follow?
Autosomal dominant inheritance pattern.
This means only one copy of the mutated gene is needed to increase the risk.
If the granddaughter inherits the mutated BRCA1 gene, what is her risk?
Her risk of developing breast cancer is significantly higher.
The inheritance of this mutation poses a serious health risk.
Fill in the blank: The BRCA1 gene mutation follows an _______ inheritance pattern.
autosomal dominant
True or False: The presence of breast cancer in previous generations guarantees the granddaughter will develop it.
False
While the risk is significantly higher, it is not guaranteed.
What can be determined using pedigrees?
If the gene for a given trait is on an autosome or on a sex chromosome
Pedigrees are useful tools in genetics for studying inheritance patterns.
What can influence the pattern of inheritance of a gene?
The location of the gene, specifically whether it is on autosomes or sex chromosomes.
Autosomes are non-sex chromosomes, while sex chromosomes determine the sex of an individual.
True or False: The pattern of inheritance is the same for genes located on autosomes and those located on sex chromosomes.
False.
The inheritance patterns can differ based on whether genes are on autosomes or sex chromosomes.
What are autosomal traits?
Traits passed on from parents to offspring independent of the X and Y chromosomes.
How are X-linked traits inherited?
Almost exclusively passed on the X chromosome.
True or False: Autosomal traits depend on the X and Y chromosomes.
False
Fill in the blank: X-linked traits are passed on the _______ chromosome.
X
describe the dominant legend
describe the recessive legend
What are the four possible modes of inheritance (MOI)?
- Autosomal Recessive
- Autosomal Dominant
- X-Linked Recessive
- X-Linked Dominant
Give an example of an Autosomal Recessive condition.
Cystic fibrosis, Sickle cell anaemia
Give an example of an Autosomal Dominant condition.
Retinoblastoma
Give an example of an X-Linked Recessive condition.
Duchenne Muscular Dystrophy
Give an example of an X-Linked Dominant condition.
Rett Syndrome
True or False: Sickle cell anaemia is an example of Autosomal Dominant inheritance.
False
Fill in the blank: _______ is an example of an X-Linked Recessive condition.
Duchenne Muscular Dystrophy
