4. Genetic Mapping and Linkage
Trihybrid Cross
8PRACTICE PROBLEM
After crossing organisms with AABBCC and aabbcc genotypes, we obtain offspring from F1 progeny that are heterozygous for all traits (AaBbCc). We then cross the F1 trihybrid with another organism that is homozygous recessive for the three traits and obtain offspring that have the following genotypes (shorthand):
ABC: 420
abc: 389
AbC: 93
aBc: 82
ABc: 62
abC: 68
aBC:12
Abc: 7
Which of the following shorthand genotypes are considered double crossovers?
After crossing organisms with AABBCC and aabbcc genotypes, we obtain offspring from F1 progeny that are heterozygous for all traits (AaBbCc). We then cross the F1 trihybrid with another organism that is homozygous recessive for the three traits and obtain offspring that have the following genotypes (shorthand):
ABC: 420
abc: 389
AbC: 93
aBc: 82
ABc: 62
abC: 68
aBC:12
Abc: 7
Which of the following shorthand genotypes are considered double crossovers?