Final answer:
In phage replication, protein fibers in the phage tail attach to specific receptors on the bacterial cell wall, which is critical for a successful infection.
Step-by-step explanation:
In the attachment step of phage replication, option (c) is correct: protein fibers in the phage tail attach to specific receptors on the bacterial cell wall. This attachment process is highly specific, allowing the phage to recognize and bind to its specific host.
The virulent phages, such as the T-even phage, follow the lytic cycle where they attach to the bacterial surface receptors, inject their genome into the host, and ultimately cause the cell to lyse, releasing new phage progeny.
Phage therapy and phage typing utilize this specificity to target bacterial infections or to identify bacterial strains, respectively. It is essential to note that during the attachment process, the phage tail acts somewhat like a hypodermic needle, and the phage genome is transferred through it, whereas the protein coat remains outside.