Question

In functional genomics, identifying a gene in a different species thought to be descended from a gene in a common ancestor is an ________?

1) homologous gene
2) analogous gene
3) orthologous gene
4) paralogous gene

Answer 1

Identifying a gene in a different species thought to be descended from a common ancestral gene is known as an orthologous gene. Orthologous genes are similar and retain their functions across species, occurring due to speciation rather than convergent evolution, which would result in analogous genes.

Step-by-step explanation:

In functional genomics, identifying a gene in a different species thought to be descended from a gene in a common ancestor is called an orthologous gene. Orthologous genes are the result of speciation, where divergence has occurred after a speciation event but the functions of the gene remain similar across species.

Analogous genes, on the other hand, are genes that have similar functions due to convergent evolution, not a common ancestry. Meanwhile, paralogous genes arise from gene duplications within the same organism, leading to new functions. Homologous genes refer more broadly to genes that are similar due to shared ancestry but can include both orthologs and paralogs.