THE MOLECULAR BASIS OF INHERITANCE
TRANSPOSONS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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60-70%
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60-75%
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70-85%
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75-90
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Detailed explanation-1: -In the late 1940s, Barbara McClintock challenged existing concepts of what genes were capable of when she discovered that some genes could be mobile. Her studies of chromosome breakage in maize led her to discover a chromosome-breaking locus that could change its position within a chromosome.
Detailed explanation-2: -In the 1950s McClintock described a novel mobile element, Suppressor-Mutator (Spm), and its complex regulation. She discovered that Spm could switch back and forth between an “inactive” form and an active form-what she called “changes of phase, ” now known to be a result of methylation.
Detailed explanation-3: -Through these experiments, McClintock recognized that breakage occurred at specific sites on maize chromosomes. Indeed, the first transposable element she discovered was a site of chromosome breakage, aptly named “dissociation” (Ds).
Detailed explanation-4: -In maize, 85% of genome is composed by transposable elements of several families.