Final answer:
The precise fold decrease caused by recA mutations in bacterial genetic recombination cannot be determined without additional information. The RecA protein plays a fundamental role in DNA repair and genetic recombination, and its dysfunction would impair these essential cellular processes.
Step-by-step explanation:
Mutations in recA diminish genetic recombination in bacteria significantly, although the exact fold decrease is not provided in the context given. The RecA protein is crucial for homologous recombination, a process vital for DNA repair and proper segregation of chromosomes during cell division in bacteria. Its homologs in eukaryotes, including Rad51, which functions during synapsis in meiosis, indicate an evolutionarily conserved role in DNA repair and genetic recombination processes.
Without proper RecA function, bacteria would experience a reduction in their ability to repair DNA and recombine genetic material, which has implications for adaptability and survival, particularly under selection pressures. This could also have effects on processes such as the accurate joining of Okazaki fragments during DNA replication or the ability to repair damage such as thymine dimers, which can arise from environmental factors and potentially lead to mutations if not corrected.