Infer why it is more difficult to make an antiviral drug that fights a virus that replicates through the lysogenic cycle than it is to make one that fights a virus that replicates through the lytic cycle.

In the lysogenic cycle, the viral genome gets incorporated into the host genome and replicates with the host genome. In the lysogenic cycle, no proteins and enzymes of the virus are formed while in the lytic cycle protein of viral capsid form and new phages generate in the host cell.

So as the viral genome integrates into the host genome in the lysogenic cycle, therefore, it is difficult for any drug to differentially act on the viral genome. So there are great chances for drugs to target the host genome in the host cell.  

But in virus that replicates through lytic cycle drugs can selectively act on viral enzyme and proteins. Therefore it is difficult to make a drug that affects lysogenic virus.

"do a testcross with a homozygous recessive plant."