Week 4- Alelle, Genotypes And Phenotypes Flashcards
What is an allele?
An allele is a variant of a gene/locus.
How many alleles and genotypes are associated with Gene X?
2 alleles, 3 genotypes.
What is a single nucleotide difference in genetics referred to as?
Single Nucleotide Polymorphism (SNP).
What is the defect that most often leads to cystic fibrosis?
Deletion of three nucleotides from the CFTR gene.
What does the ΔF508 mutation result in?
Loss of phenylalanine at position 508 in the CFTR protein.
What is the genotype and phenotype of a carrier of the cystic fibrosis allele?
Genotype: Cc; Phenotype: Normal (carrier).
What type of inheritance do mutations that result in loss of functional gene products show?
Autosomal Recessive inheritance.
What is the risk of having an affected offspring with two carrier parents?
25%.
What can be inferred from pedigrees indicating autosomal dominant inheritance?
The inheritance of the mutation corresponds with the inheritance of the disease phenotype.
What is X-chromosome inactivation also known as?
Lyonization.
Who was Charles II and what were his notable physical traits?
Last king of the Spanish Habsburg dynasty; physically disabled, mentally retarded, disfigured, and impotent.
What is the implication of consanguineous marriages on genetic disorders?
Inbred offspring are more likely to be homozygous for deleterious, recessive alleles.
What is the probability that siblings share a rare allele from first cousins?
1/4.
Fill in the blank: The probability that this individual inherits two great-grandparental ‘A’ alleles is _______.
1/64.
What does the inbreeding coefficient (f) represent?
The probability that an individual is homozygous for alleles identical by descent.
