Final answer:
Base analogs affect DNA replication by being mistakenly incorporated in place of natural bases, leading to mutations or inhibition of viral replication, and directly target the replication process rather than RNA transcription, protein synthesis, or cell division.
Step-by-step explanation:
Base analogs are compounds that can be incorporated into DNA in place of the normal bases during DNA replication. Their incorporation can lead to mutations or inhibition of replication because they may pair incorrectly with the natural DNA bases. These analogs primarily affect DNA replication because this is when the DNA polymerase enzyme can mistakenly incorporate these analogs into the newly synthesized DNA strand. This can lead to the failure of viral replication, as the resulting DNA is often non-functional or less efficient. It is important to note that base analogs typically do not affect RNA transcription or protein synthesis directly, as these processes do not involve the synthesis of DNA strands where base analogs would be incorporated. Likewise, although cell division relies on accurate DNA replication, the direct effect of base analogs is exerted during the replication process itself rather than the broader cell division process.