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Complete each sentence using the words or phrases. (Not all words and phrases are used.) homologous chromosomes nonsister genetic recombination sister meiosis disappeared physical lexchange of parts mitosis I were rearranged chiasmata Il physical markers traits nonhomologous chromosomes || genetic markers In 1909, cytologist Frans Janssens described microscopic chromosomal structures that were viewed during prophase 1 ho called these structures The structures Janssons saw seemed to represent regions in which crossed over each other. chromatids of Thomas Hunt Morgan suggested that chiasmata were sites of chromosome breakage and exchange that resulted in In the 19300, experiments done by Curt Stern using Drosophila and Harriet Creighton and Barbara McClintock using com provided evidence that recombination is associated with between chromosomes. Stern, Creighton, and McClintock followed the inheritance of chromosomes using that could be viewed in the microscope. Alles for alternate forms of also resided on the marked chromosomes and are called genetic markers Recombinant offspring were identified using the In the recombinant offspring, the physical markers Indicating that exchange of DNA has occurred between homologous chromosomes.

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1n 1909, cytologist Frans Janssens described microscopic chromosomal structures that were viewed during prophase I of Meiosis he called these structures chiasmata.

The structures Janssens saw seemed to represent regions in which nonsister chromatids of homologous chromosomes crossed over each other.

Thomas Hunt Morgan suggested in 1916 that chiasmata were sites of chromosome breakage and exchange that resulted in genetic recombination.

In the 1930s, publication of studies by Curt Stern in Drosophila and by Harriet Creighton and Barbara McClintock in corn showed that recombination is associated with actual physical exchange of parts between chromosomes.

Stern Creighton and McClintock followed the Inheritance of chromosomes using Physical marksre that could be viewed in microsope. Alleles for alternative form of Traits also resided on the  marked chromosomes and are called genetic markers.

Recombinant offspring were identified using the genetic markers . In the recombinant offspring , the physcical markers were disappeared, indicating that exchange of DNA had occured between homologous chromosomes.