Question

In phage replication...

a. only the phage nucleic acid enters the bacterial cell
b. the whole phage particle enters the cell and the protein outer coat is removed
c. multiple phage particles enter the same host bacterial cell at the same time
d. only the phage protein enters the bacterial cell

Answer 1

In phage replication, only the phage DNA enters the bacterial cell. The protein coat remains outside, and the DNA utilizes the cell's machinery to produce new phages via the lytic or lysogenic cycle.

Step-by-step explanation:

The question pertains to the process of phage replication, specifically what enters the bacterial cell during this process. In phage replication, only the phage DNA enters the bacterial cell, whereas the protein coat (also known as the capsid) does not. The phage DNA then hijacks the bacterial cell's machinery to replicate and produce new phage particles.

This process can occur via two cycles: the lytic cycle, where the phage replicates and eventually causes the bacterial cell to lyse, releasing new phages; and the lysogenic cycle, where the phage DNA integrates into the host's genome and replicates along with it without immediately destroying the cell. It is important to note that the Hershey and Chase experiments confirmed that DNA, not protein, is the genetic material of phages. They used radioactive isotopes to trace the fate of DNA and protein during phage infection, which provided the conclusive evidence.