A heterozygous AaBb fruit fly is testcrossed to a homozygous recessive aabb partner. The phenotypic counts of 1000 progeny are listed.
What is the recombination frequency between the A and B loci?
- Acheck_circle
Approximately 20%, indicating linked genes about 20 mu apart
- B
Cannot be calculated from the data
- C
Approximately 1%, indicating tight linkage
- D
Exactly 50%, indicating unlinked genes
Explanation
Recombinants = 95 + 105 = 200 of 1000 total = 20%. Recombination below 50% indicates linkage; the value (~20 mu) estimates map distance between A and B.