Final answer:
An HFR bacterial strain can indeed contain the genes a, b, c, and d, which can be transferred to F- recipient cells during mating, and this process is vital for gene mapping in bacteria.The final answer is true.
Step-by-step explanation:
True, an HFR bacterial strain can contain the genes a, b, c, and d. High-frequency recombination (HFR) strains are a type of bacteria that have the F plasmid integrated into their chromosome. When HFR cells are mated with F- recipient cells (which can have mutations in any gene, including a, b, c, or d), these genes can be transferred through a mating bridge. This process is instrumental in mapping bacterial genes, as it allows for the determination of gene loci and their relative distances on the chromosome based on the timing of conjugation and the subsequent acquisition of functional genes from the HFR strain. Through such experiments, scientists have gained a deeper understanding of the linear arrangement of genes on bacterial DNA and the size of individual genes.