Read Gene Duplication and Orthologues
A concise NSEB read for gene duplication and orthologues, followed by its linked source question.
Gene Duplication and Orthologues is the central idea in this question pattern. Identify the condition in the stem before applying the method below.
Core idea
Speciation separates descendant lineages, so corresponding genes separated by speciation are orthologues. A duplication within a lineage creates paralogues; their copies can diverge and acquire new functions. Polyploidy duplicates whole chromosome sets and is a genome-level duplication, not itself a speciation event.
Speciation separates orthologues; duplication makes paralogues
Orthologues arise by speciation, whereas paralogues arise by gene duplication. Haemoglobin and myoglobin are classic
paralogues, and duplicated genes can diverge to acquire novel functions. Polyploidy is a genome-level duplication rather than
the speciation event labelled P. Therefore B, C and D are correct according to the official key. Correct: B, C, D.
OlympIQ exam lens
- ✓Speciation separates descendant lineages, so corresponding genes separated by speciation are orthologues.
Read labels and trends first, then check that each option follows from the figure.
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