Relationship between Genotype and Phenotype Molecular Basis for Relationship between Genotype and Phenotype genotype DNA DNA sequence transcription RNA translation amino acid sequence protein function phenotype organism

Mutation: Levels of Hereditary Change Gene (Point) Mutation: One allele changes to a different allele. Effects are limited to that locus. Chromosome Mutation: Changes occur at the chromosome level. Multi-locus effects are not unusual.

Types of Chromosome Mutations

Changes in Chromosome Number I. Classes A. Aberrant Euploidy B. Aneuploidy II. Euploidy A. Monoploid (x): chromosome number in a basic set B. Euploidy: multiples of monoploid number C. Polyploid: euploid with > two sets of chromosomes III. Examples of Polyploidy A. Autopolyploidy : multiple chromosome sets from one species B. Allopolyploidy: chromosome sets from different species

Meiotic Pairing in Triploids

Colchicine Induces Polyploidy

Chromosome Pairing in an Autotetraploid

Origin of the Amphidiploid Raphanobrassica

Origin of Three Allopolyploid Species of Brassica

Polyploidy in Animals Parthenogenesis - development of unfertilized egg into embryo polyploidy in leeches, flatworms, brine shrimp polyploidy in salamanders, lizards Polyploid frogs and toads undergo sexual reproduction. Polyploid fish (such as salmon, trout) are not unusual. Triploid oysters are of economic value. In general, polyploid mammals are not viable.