Biology Forum Genetics Help with a Genetics Problem

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    • #4020
      nernab
      Participant

      A plant species X with n=5 was crossed with a related species Y with n=7. The F1 hybrids produced only a few pollen grains, which were used to fertilize the ovules of species Y. A few plants were produced from this cross, and all had 19 chromosomes. Following a self-fertilization, the F1 hybrids produced a few F2 plants, each with 24 chromosomes. These plants were phenotypically different from either of the original species and were highly fertile. Explain by diagram and description the events that produced these fertile F2 hybrids.

      Can anyone help me. 😕

    • #43294
      MrMistery
      Participant

      Look it up. I have read today this stuff. You will find it in your textbook, i guarantee it 100%

    • #43357
      sham
      Participant

      Possible scenario.
      Plant X (n=5) cross Plant Y (n=7).
      You get hybrid 2n=12 (from 5+7).
      This hybrid produced 2n gamete (paternal side = pollen grain) due to non-disjunction (n=12).
      Cross with ovules from Plant Y (n=7), and you get F1 (3n=19).
      To get F2 plant with 24 gametes, F1 plant must produce gametes exclusively from the paternal side (n=12) and these fused to form zygote which will develop into fertile F2 hybrid.
      Sham

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