Linked Genes: Genes on the same chromosome tend to be inherited together if they are close.
Crossing Over: Occurs during Prophase I of Meiosis, mixing maternal & paternal alleles.
Recombination Freq: Formula: (Recombinants / Total Offspring) × 100%
Map Units (cM): 1% RF = 1 map unit. Max value is 50% (unlinked behavior).
Tags
GeneticsLinkage MapCrossing OverMeiosis
1000
Total Offspring simulated
800
Parental Types
200
Recombinant Types
20%
Recombination Freq (RF)
Distance between Gene A and B 20 cM
Adjusting the physical distance on the chromosome (map units) directly changes the probability of a crossing-over event happening exactly between them.
Testcross Results (AaBb × aabb)
A_ B_ (Parental)400
aa bb (Parental)400
A_ bb (Recombinant)100
aa B_ (Recombinant)100
50% Upper Limit
If genes are very far apart on the same chromosome (or on different chromosomes), multiple crossing over events make them assort independently. Recombination Frequency cannot exceed 50%.