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Topics: Gene, DNA / Pages: 12 (2135 words) / Published: Oct 18th, 2014
Study4Finals: Bio 97 ADL 10 & ADL 11 Homework - Google文档

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https://docs.google.com/document/d/1G8cf7cZrQbRDH7UG05fGtBUmSJ...

Study for Bio 97 Notes for Finals (ADL HW 10)
Item #1

Recombination occurs when combinations of alleles not found in either parent are placed into gametes during meiosis in the F generation. The F can be thought of as having been formed
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1 from two haploid “input” gametes.
In this case, the F is a dihybrid with AB on one chromosome and ab on the other
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chromosome. You can tell this by looking at the parents. The F1 hybrid got AB from one parent and ab from the other parent (AB/ab). A dihybrid that is AB/ab can produce four possible “output” gametes through meiosis. Output gametes that match one of the input gametes are nonrecombinant (AB or ab). Output gametes with new combinations of alleles are recombinant (Ab or aB).
Its important to realize that its also possible to have a dihybrid who is Ab/aB instead. In this case, one parent was AAbb and the other parent aaBB. A dihybrid who is Ab/aB can also produce four possible "output" gametes through meiosis, but in this case the nonrecombinant

9/15/2014 9:45 PM

Study4Finals: Bio 97 ADL 10 & ADL 11 Homework - Google文档

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https://docs.google.com/document/d/1G8cf7cZrQbRDH7UG05fGtBUmSJ...

gametes are Ab or aB and the recombinant gametes are AB or ab. In Part C, be sure to check the parents of the F1 trihybrid to determine their configuration of alleles before answering the question. Which gametes are nonrecombinant versus recombinant depends how the alleles are organized in the F1 trihybrid.

In a testcross with a homozygous recessive line (tester), the tester will contribute only recessive alleles that do not affect the F phenotypes. Therefore, such testcrosses allow you to
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determine the haploid genotype of the gametes produced by the F dihybrid.
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9/15/2014 9:45 PM

Study4Finals: Bio 97 ADL 10 & ADL 11 Homework - Google文档

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