Final answer:
RecA, RadA, and Rad51 are homologous proteins that are conserved throughout evolution. RecA is involved in DNA repair in bacteria, while Rad51 plays a role in synapsis during meiosis in eukaryotes.
Step-by-step explanation:
RecA, a bacterial protein, is homologous to RadA in Archaea and Rad51 in Eukaryotes. While RecA is involved in DNA repair in bacteria, Rad51 plays a role in synapsis during meiosis in eukaryotes. The fact that these homologs are conserved throughout evolution suggests that their functions in DNA repair predated their use in synapsis and crossing over in eukaryotes.