A test cross was made between true-breeding EEWW flies and eeww flies. The resulting F1 generation was then crossed with eeww fl

Question

3 years ago

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A test cross was made between true-breeding EEWW flies and eeww flies. The resulting F1 generation was then crossed with eeww fl

ies. 100 offspring in the F2 generation were examined, and it was discovered that the E and W genes were not linked. Which is the correct genotype of the F2 offspring if the genes were linked and if the genes were not linked?

Biology

1 answer:

Anton [14] · Answer 1 · 2022-03-17T10:30:30+03:00

Explanation:

<h3><u>If the genes were linked:</u></h3>

<u>Parental cross: EW/EW X ew/ew</u>

F1 genotype: EW/ew

F1 Gametes:

- Parentals (more abundant): EW and ew

- Recombinant (less abundant): Ew and eW

<u>Test cross: EW/ew X ew/ew</u>

<u>F2 genotypes:</u>

Parentals: EW/ew; ew/ew;
Recombinant: Ew/ew; eW/ew

<h3><u>If the genes are not linked:</u></h3>

<u>Parental cross: EEWW X eeww</u>

F1 genotype: EeWw

F1 gametes: EW, Ew, eW, ew. Genes assort independently, so all of the possible gametes of the F1 individual will have the same probability.

<u>Test cross: EeWw X eeww</u>

<u>F2 genotypes:</u>

1/4 EeWw, 1/4 Eeww, 1/4 eeWw, 1/4 eeww