Which of the following is a good example of two genes that are orthologous?
A) the promoter and the repressor genes of the lac operon in E. coli
B) the genes for the first two enzymes in the glycolytic pathway
C) the gene for the photosynthetic enzyme RuBisCO in a fern and in an oak
D) the human gene for the cell surface protein Siglec-12, and the human pseudogene Siglec-13
E) None of these pairs are orthologous.

Question

Quizplus · Accepted Answer

Orthologous genes are genes in different species that evolved from a common ancestral gene through speciation. The gene for the photosynthetic enzyme RuBisCO is a good example of two orthologous genes because it is found in both ferns and oaks, which diverged from a common ancestor millions of years ago. The other choices involve genes within the same species or genes that have undergone different evolutionary processes (such as a pseudogene) and are not considered orthologous.

Which of the Following Is a Good Example of Two