How to solve pedigree probability problems - 1

Key terms Term Meaning Pedigree Chart that shows the presence or absence of a trait within a family across generations Genotype The genetic makeup of an organism (ex: TT) Phenotype The physical characteristics of an organism (ex: tall) Dominant allele Allele that is phenotypically expressed over another allele Recessive allele Allele that is only expressed in absence of a dominant allele Autosomal trait Trait that is located on an autosome (non-sex chromosome) Sex-linked trait Trait that is located on one of the two sex chromosomes Homozygous Having two identical alleles for a particular gene Heterozygous Having two different alleles for a particular gene Pedigrees Pedigrees are used to analyze the pattern of inheritance of a particular trait throughout a family. Pedigrees show the presence or absence of a trait as it relates to the relationship among parents, offspring, and siblings. Pedigrees represent family members and relationships using standardized symbols. By analyzing a pedigree, we can determine genotypes, identify phenotypes, and predict how a trait will be passed on in the future. The information from a pedigree makes it possible to determine how certain alleles are inherited: whether they are dominant, recessive, autosomal, or sex-linked. To start reading a pedigree: Determine whether the trait is dominant or recessive. If the trait is dominant, one of the parents must have the trait. Dominant traits will not skip a generation. If the trait is recessive, neither parent is required to have the trait since they can be heterozygous. Determine if the chart shows an autosomal or sex-linked (usually X-linked) trait. For example, in X-linked recessive traits, males are much more commonly affected than females. In autosomal traits, both males and females are equally likely to be affected (usually in equal proportions). #genetics #homozygous #Heterozygous #RecessiveAllele #genotype #phenotype #pedigree #DominantAllele #AutosomalTrait #SexlinkedTrait #PedigreeAnalysis #pedigreeAnalysisPractice #pedigreeAnalysisGenetics #pedigreeAnalysisProbability #pedigreeAnalysisAnswers #pedigreeCharts #HowToSolvePedigreeProblems #solvePedigreeProblems #solvingPedigreeProblems #pedigreeProblemsAndSolutions #howToAnalyzePedigree #analyzingPedigree #geneticsProblems