BRAINCAKEIdentifying Linked Genes
Linkage is usually identified from the results of a dihybrid test cross, in which a double heterozygote (AaBb) is crossed with a double homozygous recessive (aabb).
If the genes are unlinked, the four phenotypes appear in a 1 : 1 : 1 : 1 ratio. If they are linked, the offspring show two large classes and two small classes:
• the two large classes have the parental combinations of characteristics (no crossing over between the genes)
• the two small classes are the recombinants, produced when crossing over separated the alleles
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More in Genetic Information
- Chi-Squared Test
- Chi-Squared Test - Monohybrid Crosses
- Chi-Squared Test- Dihybrid Crosses
- Gene Linkage
- Chromosome Mapping
- Sex-Linkage
- Pedigree Diagrams
- The Albino Trait
All 30 lessons in Genetic Information · All Edexcel A-level Biology topics