Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

What role do viruses play in the host genome?

1. They delete segments of DNA

2. They can insert their DNA into the host genome

3. They protect the host DNA

4. They enhance the host's genome replication

The correct answer is: They can insert their DNA into the host genome

Viruses can indeed insert their DNA into the host genome, which is a significant aspect of their interaction with host cells. This process occurs in certain types of viruses, particularly retroviruses, which have the ability to reverse transcribe their RNA into DNA and integrate it into the DNA of the host cell. This integration can lead to a variety of outcomes, including the alteration of the host's genetic expression and the potential for the host to produce new virus particles. When viral DNA integrates into the host genome, it can be transcribed and translated alongside the host's own genes. This integration is crucial for the viral lifecycle and allows the virus to replicate as the host cell divides. The consequences of this integration can range from benign to pathological, depending on how the integrated viral DNA affects the host's cellular functions. Understanding this role of viruses helps highlight their complex interactions with host organisms, showcasing not just their potential for causing disease but also their involvement in evolutionary processes and genetic exchange between species.