Ch 14.1: Mendel and the Gene Idea Flashcards
What kind of disease is cystic fibrosis?
an autosomal recessive disease
What is the dominant allele in cystic fibrosis?
chloride ion channel protein
What is the recessive allele in cystic fibrosis?
no channel proteins, which results in a high chloride ion concentration inside cells leading to an uptake in H2O
What does cystic fibrosis cause?
it causes mucus that coats cells to be thicker and stickier, poor absorption of nutrients, and chronic infections (bronchitis)
What is the mulitplication rule?
the probability that two or more independent events will occur together is the product of their individual probabilities
What is the addition rule?
the probability that any one of two or more mutually exclusive (one or other) events will occur is calculated by adding together their individual probabilities
What is complete dominance?
occurs when phenotypes of the heterozygote and dominant homozygote are identical
What is incomplete dominance?
the phenotype of F1 hybrids is somewhere between the phenotypes of the two parental varieties
What is codominance?
two dominant alleles affect the phenotype in separate, distinguishable ways
What is Tay-Sachs Disease?
it is a fatal inherited disorder, a dysfunctional enzyme causes an accumulation of lipids in the brain
What kind of disease is Tay-Sachs disease?
a recessive disease (rr), which is incompletely dominant (codominant)
Are dominant alleles more common in populations?
Dominant alleles are not necessarily more common in populations than recessive alleles
What is pleiotropy?
most genes have multiple phenotypic effects
What is epistasis?
expression of a gene at one locus alters the phenotypic expression of a gene at a second locus
What are quantitative characters?
those that vary in the population along a continuum, which usually indicates a polygenic inheritance
