Gene Linkage and Mapping
Remember Mendel’s Laws Law of Segregation Alleles for a trait will separate independently from each other during gamete formation Law of Independent Assortment Homologous chromosomes will separate independently from other homologous chromosomes
Linked Genes A1, B1 & C1 are linked genes
Crossing over can UNLINK genes! Recombinants
higher rate of crossing over Genes further apart Less likely to be linked = = Linked Not linked
Purple (R) is dominant over red (r) RRLL x rrll Purple (R) is dominant over red (r) Long pollen (L) is dominant over round pollen (l) RrLl
RrLl
RrLl The law of independent assortment does not always apply with linked genes