Chapter 3 Flashcards
What is the difference between co-dominance and semi-dominance?
Co-dominance: each trait is expressed equally
Semi-dominance: not equl expression of both allelles
definition of a gene?
a functional unit of DNA
term: a unique chromosomal location defining the position of an individual gene
loci/locus
Term: alternative versions of a gene
allelles
Term: heterozygote has an intermediate phenotype
semidominant trait
Term: few loci determin trait
oligogenic
Term: many loci determine trait
polygenic
What is does mendels first law describe?
The law of segregation/law of purity of gamets. Each characteristic trait is determined by two factors, one from each parent
What does Mendels second law describe
The law of independet assortment. two or more different traits are determined by two or more pais of different factors and each pair is inherited independently from the other
Which three things charaterize the inheritance of mitochondrial DNA?
- inheritance solely from mother
- affects both sexes
- heteroplasmy
Term: mutations in different genes cause the same disease
Locus heterogeneity
Term: different mutations within same gene result in the same phenotype
Allelic heterogeneity
Term: mutations in same gene results in two or more different phenotypes (different diseases)
Clinical heterogeneity
What is the requirement for complementation to happen when crossing two affected individuals?
Complementation will occur only if the mutations are in different genes
Term: the genetic effect of a single gene on multiple phenotypic trait
pleiotropy
Term: when the effects of one gene masks the effects of another
Epistasis
Term: when a human charateristic/syndrome is only manifested when the gene is inherited from one particular sex
Imprinting
What is the difference between dichotomous and continous traits?
dichotomous: present or absent
continous: quatitative
The Hardy-Weinberg distribution describes what?
the relation between allelle frequency and genotype frequencie in a population
What three factors impact genetic frequency?
- genetic drift
- effects of new mutations
- natural selection
