[Campbell Biology P.614] What is the primary distinction between orthologous genes and paral... | Practice Question

What is the primary distinction between orthologous genes and paralogous genes, according to the provided text and Figure 26.18?

  • A: Orthologous genes arise from gene duplication within a species, while paralogous genes arise from speciation events.
  • B: Orthologous genes are homologous genes resulting from speciation, while paralogous genes are homologous genes resulting from gene duplication within a species.
  • C: Orthologous genes are found in different species, and paralogous genes are found only within the same species.
  • D: Orthologous genes always have identical functions, while paralogous genes always have different functions.

Explanation

The text explicitly states: 'Accounting for such duplications leads us to distinguish two types of homologous genes Figure 26.18 : orthologous genes and paralogous genes. In orthologous genes ... the homology is the result of a speciation event. b Formation of paralogous genes: within a species, Ancestral gene undergoes Gene duplication and divergence'. Figure 26.18 further illustrates that orthologous genes arise from speciation, leading to homologous genes in different species, while paralogous genes arise from gene duplication within a single species.