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Using the rules of probability, place the boxes in the columns appropriate to th

ID: 190933 • Letter: U

Question

Using the rules of probability, place the boxes in the columns appropriate to the different matings. Phenotypic ratio of the progeny will be 9:3:3:1. ic ratio of the Probability of an SS Probability of an SS Rr progeny will be 1:1 offspring is 100%. offspring is 50%. Probability of offspring The chance of Ss Rr Genotypic ra tio of the progeny will be 1:2:1. Probability of an ss Rr offspring is 25%. homozygous recessive offspring is 25%. for the R gene is 25%. SS RrX SS Reset Prev 1 of 14 Next >

Explanation / Answer

1) Cross between SSRr and SSrr.

SSRr X SSrr

gametes formed SR and Sr Sr and Sr

Next generation

Phenotypic ratio of the progeny will be 1:1.

Probability of an SS offspring is 100%.

Probability of an SSRr offspring is 50%.

2) Cross between SsRR and Ssrr

SsRR X Ssrr

Gametes formed SR and sR Sr and sr

Next generation

Genotypic ratio of the progeny will be 1:2:1.
The probability of an ssRr offspring is 25%.

3) Cross between SsRr and SsRr

SsRr X SsRr

Gametes formed SR, Sr, sR and sr   SR, Sr, sR and sr

Next generation

Phenotypic ratio of the progeny will be 9:3:3:1.

Probability of offspring homozygous recessive for the R gene is 25%.

The chance of SsRr offspring is 25% = 4/16 = 0.25 x 100 = 25%

Male/ Female SR Sr Sr SSRr SSrr Sr SSRr SSrr