THE MOLECULAR BASIS OF INHERITANCE
GENE MUTATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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inversion
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duplication
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insertion
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deletion
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Detailed explanation-1: -Inversions. An inversion occurs when a chromosome breaks in two places; the resulting piece of DNA is reversed and re-inserted into the chromosome.
Detailed explanation-2: -Chromosomes may break “spontaneously” or by the effects of chemical and physical agents (ionizing radiation). The breakage may involve only one of the chromatids or both (isochromatid breaks) (see Fig. C87).
Detailed explanation-3: -Types of deletion include the following: Terminal deletion – a deletion that occurs towards the end of a chromosome. Intercalary/interstitial deletion – a deletion that occurs from the interior of a chromosome.
Detailed explanation-4: -Insertional translocations may occur within a chromosome or between two chromosomes. Three breakpoints are required, two to effect the interstitial deletion of a chromosome segment and one to allow the insertion of the segment into another site.