Difficulty: Easy
Correct Answer: Transposons
Explanation:
Introduction / Context:Mobile DNA elements reshape genomes across evolution. They can insert, excise, or copy themselves, influencing gene regulation, genome size, and mutational landscapes in both prokaryotes and eukaryotes.
Given Data / Assumptions:
Concept / Approach:Such sequences are called transposons (or transposable elements). DNA transposons use transposase for excision/integration, while retrotransposons use an RNA intermediate and reverse transcription.
Step-by-Step Solution:
Identify the defining feature: intragenomic mobility.Map to terminology: "transposons" is the accepted umbrella term.Exclude external agents (viruses) and non-mobile genomic features (introns, centromeres).Thus, the correct term is transposons.Verification / Alternative check:Classic McClintock maize elements and modern genomic surveys reveal abundant transposable element families that relocate or copy within genomes.
Why Other Options Are Wrong:
Common Pitfalls:Confusing retroviruses with endogenous retrotransposons; while related mechanisms exist, the term sought is transposons.
Final Answer:Transposons
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