Details: the authors generate hybrids between two species of monkeyflowers, M. n

Question

Details: the authors generate hybrids between two species of monkeyflowers, M. nasutus and M. guttatus. We can imagine there is a gene Dwith two alleles: Du is the allele from M. nasutus, and Dg is the allele from M. guttatus. 11. In the next experiment, the authors generate nearly isogenic lines (NILs) by repeated backcross the F1 plants to M. nasutus plants for 5 generations. At a given locus in the genome, every F1 plant is heterozygous. After each backcros locus is cut in half. s, the number of plants that are expected to be heterozygous at that After 4 generations of backcrossing, how many plants should still be heterozygous at that locus? (0.5 pt) a. b. Near the proposed distortion locus, what percentage of plants were still heterozygous? (0.5 pt) 12. The authors examined the ovules of these NILs, and did not find an increase in mortality/infertility. Based on this finding, is the increased rate of transmission of the D° allele most likely due to something happening during. or after meiosis? (1 pt) 13. Based on their data, what is the authors' best hypothesis for what is causing such strong transmission distortion in these hybrid plants? (1 pt)

Explanation / Answer

Ans-11 as we know heterozygous will have alleles Dg and Dm while the M.nasattus will have Dn and Dn. By plotting a punnet square we got

So the F2 have two heterozygotes and two homozygous.

When we cross them again with Dn and Dn we will get 4×2 homozygous, 2×2 heterozygous, and 2×2 homozygous so total it become 12 homozygous and 4 heterozygous.

When we again cross in F4 we will get 12×4 homozygous, 4×2 heterozygous, and 4×2 homozygous. So total we get 56 homozygous and 8 heterozygous.

In F5 we will get 56×4 homozygous, 8×2 heterozygous, 8×2 homozygous so total it become 16 heterozygous and 464 homozygous

Ans-11(a) the 16 out of 480 will be heterozygous.

Ans-11-(b)the heterozygous after 5 generation will be 16/480×100= 3.33%

Dn Dn Dg Dg Dn Dg Dn Dn Dn Dn Dn Dn

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