Answer:
The bacterial DNA gets degraded at step 3 of the viral lytic cycle.
Explanation:
Viruses are organisms that are incapable of replicating on their own, hence, they require a living host which they infect and use its replicational ability to reproduce theirselves. The infection cycle of this virus is regarded as its replication cycle. Viruses employ either the LYTIC or LYSOGENIC cycle for infection.
The lytic cycle involves killing of their host cell at the end of the cycle. Generally, the cycle starts with the attachment of my the virus to the cell membrane of its host using specific receptor sites (step 1). It then penetrates the host cell as seen in step 2.
After penetration, the virus then secretes certain degrading enzymes called ENDONUCLEASES that degrades the bacterial DNA. After which the virus uses the replicational and gene expressing ability of the host to transcibe its genetic material and replicate itself. This process called SYNTHESIS occurs in step 3.
Hence, the yellow ring in the image that represents bacterial DNA disappears in step 3 (synthesis stage) because it gets degraded by viral digesting enzymes.