Female fruit flies from a true-breeding strain with yellow body and cut wings ar
ID: 101438 • Letter: F
Question
Female fruit flies from a true-breeding strain with yellow body and cut wings are mated to male fruit flies from a true breeding strain that is wild type for both body color and wings. In the F1 generation, all of the female flies are wild type for both characters while all of the male flies have yellow bodies and cut wings. The F1 males and females are intercrossed, and among 1000 male progeny the following is observed:
425 yellow body and cut wings
405 wild type body and wild type wings
90 yellow body and wild type wings 80 wild type body and cut wings
Using the information from this previous question above ^
What would be the recombination frequency (expressed as a decimal) if the progeny had been as follows:
190 yellow body and cut wings
210 wild type body and wild type wings
45 yellow body and wild type wings
55 wild type body and cut wings
(Note that I am asking for recombination frequency (a decimal value) not map distance in centiMorgans.)
Explanation / Answer
Recombination frequency is defined as the frequency with which a single chromosomal crossover takes place during meiosis. Recombination frequency is a measure of genetic linkage and is calculated by the ratio of total number of recombinants by total number of offsprings.
Recombination frequency
= ((number of recombinants)/(number of offsprings)) x 100
Therefore, the recombination frequency for the first question is,
RF = (80+90)/1000
= 0.17 (17%).
The recombination frequency for the second question is,
RF = (45+55)/500
= 0.2 (20%).
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.