Finding proportion of gametes with a particular genotype for dihybrid cross? and Peperomia 'Smaragd' inflorescence - flowers

Finding proportion of gametes with a particular genotype for dihybrid cross?

In tomato plants, a gene controlling fruit shape has 2 alleles: O (round) and o (oval). A gene controlling inflorescence (position of the flowers) has two alleles: S (simple) and s (compound). The map distance between the two genes is 22 cM. A pure-breeding plant with oval fruit and compound inflorescence is crossed with a pure-breeding plant with round fruit and simple inflorescence. The F1 have round fruit and simple inflorescence. The F1 are then crossed to plants with oval fruit and compound inflorescence and 100 offspring are produced. How many of the offspring would you expect to have oval fruit and simple inflorescence?


This is a practice test question

does it matter that there is 22% recombination??? otherwise I think I could work it out using the 9:3:3:1 ratio


inflorescence best answer:

Answer by Peter S
The genes are linked on the same chromosome and are 22cM units apart.This means there will be 22% recombinant offspring and 78% parental offspring.

Parental = oval/compound = 39. And round/simple = 39.
Recombinant = oval/simple = 11. And round/compound = 11.

inflorescence

Peperomia 'Smaragd' inflorescence - flowers


100313-03
In fact these are the only open flowers and they are very tiny measuring about 2 mm (0.078 in.).
All the rest are hundreds of buds on the vertical spike.

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