. Gene duplication Gene duplication is the result of one of two processes: retro
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Question
. Gene duplication Gene duplication is the result of one of two processes: retrotransposition or unequal cross-over. 1. Describe what is meant by retrotransposition. (1 pt) 2. What are the four "footprints" that distinguish a duplication by retrotransposition? (2 pts) 3. Describe what is meant by unequal cross-over (1 pts) 4. What are the three "footprints" that distinguish a gene dupliation by unequal cross over? (2 pts) 5. Since duplicated genes are redundant, what is their fate? (2 pts) 6. What is the difference between orthologs and paralogs? (2 pts)Explanation / Answer
Retrotransposition is the transposition of transposon form one position to another in the genome of a cell by forming an intermediate RNA transcript from which a copy of the DNA of the transposable element is made using reverse transcriptase and inserted into a new location in the genome. Retrotransposition leave distinctive "footprints" in the genome. Retrotransposed gene lack introns and lack the nearby regulatory sequences found near the original. Fate of duplicated gene is that when a DNA sequence is duplicated via retrotransposition, the original gene should continue to produce a normal product. The duplicated sequence are redundant and may accumulate mutations without the consequence to the phenotype. The duplicated gene might even change function over time and become an entirely new gene instead of just one extra copy of an existing gene. This means it creates an additional DNA. Gene duplication may result in entirely new possibilities for gene function. Unequal crossover is a type of gene duplication or deletion event that deletes a sequence in one strand and replaces it with a duplication from its sister chromatid in mitosis or from homologous chromsome during meiosis. Unequal cross over is a change mistake caused by proteins involved in managing genetic recombination that occutrs during meiosis. This happens when a homologous chromosomes do not synapse correctly dring prophase in meiosis I. Results in one chromsomes that contains the deletion and another one contains redundant DNA. Footprint: found in tandem with original gene, contains same introns as parents.
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