Question

A portion of the linkage map of chromosome 2 in the tomato is illustrated here. The oblate phenotype has flattened fruit, peach results in hairy fruit (like a peach), and compound inflorescence means clustered flowers.

o(oblate) ci (compound inftluorescence) p (peach)
15 cM 20 cM
Among 1,000 gametes produced by a plant of genotype o ci +/+ + p, what types of gametes would be expected, and what number would be expected of each? Assume that the chromosome interference across this region is 80%.

Answer 1

Expected gametes : o+ ci+ p+,o- ci- pi-, o+ci- pi+,o- ci+ pi-, o+ci+ pi-, o- ci- pi+

Step-by-step explanation:

Genetic distance between genes is equal to the recombination frequency, so the total number of recombinant gametes can find out by multiplying the recombination frequency of both sides to the total number of gametes.

Interference= .80;

Coefficient of incidence

= 1 - 0.80

= 0.20

15cM = 15% recombination,

20cM = 20% recombination.

Then, Number of recombinant offspring

= 15 x1000/100

= 150,

Gametes expected= o+ ci+ p+,o- ci- pi-, o+ci- pi+,o- ci+ pi-, o+ci+ pi-, o- ci- pi+