THE MOLECULAR BASIS OF INHERITANCE
TRANSPOSONS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Restriction of the IS element
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Integration of the transposon
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Formation of the RNA intermediate
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Restriction of the host genome
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Detailed explanation-1: -Explanation: The transposase performs three functions in the transposition of the IS element. First, it precisely excises the IS element from the transposon. Second, it makes staggered cut in the target DNA segment. Last, it ligates the IS element within the target site.
Detailed explanation-2: -Transposons are repetitive DNA sequences that have the capability to move (transpose) from one location to another in genome. Transposon movement can result in mutations, alter gene expression, induce chromosome rearrangements and, due to increase in copy numbers, enlarge genome sizes.
Detailed explanation-3: -Retrotransposons. Retrotransposons mobilize via an RNA intermediate by a copy-and-paste mechanism and remain active in most mammalian genomes. They can be subdivided into two general classes, depending on whether they contain or lack LTRs (Figure 1).
Detailed explanation-4: -Transposons can be divided based on the mechanism of transposition and integration. Class I elements, retrotransposons, use an RNA intermediate that is reverse-transcribed into a cDNA copy that reintegrates into a new genomic home.