Explore BrainMass

Explore BrainMass

    Multi-generational plant breeding

    Not what you're looking for? Search our solutions OR ask your own Custom question.

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    Each plant was crossed with normal (leafy) pure-bred plants to generate the following phenotypic ratios:

    F1 phenotype F2 phenotype

    Line 1 x leafy all leaves 3:1 leaves/no leaves

    Line 2 x leafy all no leaves 3:1 no leaves/leaves

    Line 1 X line 2 all no leaves 13:3 no leaves/leaves

    Why do two apparently similar plant lines produce such different results? For each cross depicted in the table, show the genotypes of all parental, F1, and F2 plants. Show the results of a total of three crosses.

    I cannot put togeter Line 1 x Line 2...single lines don't give me problems (I think)but I cannot figure out crossing them togeter. Help

    © BrainMass Inc. brainmass.com December 16, 2022, 7:44 am ad1c9bdddf

    Solution Preview

    Whenever you see a 13:3 ratio you should immediately think of dominant suppression epistasis. That is certain genes have the ability to suppress the expression of a gene at a second locus. Let us say, as in your question, that synthesis of a leaf is controlled by the A gene and the suppression of synthesis is controlled by the B gene. Both A and B are dominant traits. The F1 plant with the genotype AaBb will not produce leaves because of the presence of the dominant B allele.

    Genotype ...

    Solution Summary

    This question is a typical Mendelian genetics problem. There are two pure-breeding plant lines that generate a 3:1 and a 13:3 ratio of offspring.

    The solution answers the question and explains the methodology used to generate the answer. The solution is also provided in *.doc format for easier editting.