Retrovirus Instant

Perhaps most surprisingly, retroviruses have played a massive role in human evolution. When a retrovirus infects a sperm or egg cell, its genetic material can be passed down to future generations. Over millions of years, these "fossil" viruses have accumulated in the human genome and are known as . Scientists estimate that 8% to 9% of the human genome is composed of these ancient viral remnants. While most are now inactive mutations, some have been repurposed by our bodies to help regulate the immune system or even aid in the development of the placenta during pregnancy. Conclusion

: The host cell's machinery mistakenly treats the provirus as one of its own genes, producing viral mRNA and proteins. These components assemble into new, immature viral particles that bud off from the cell. Retrovirus

: Another enzyme, integrase , carries this viral DNA into the cell's nucleus and "clips" it into the host's own DNA. At this stage, the integrated viral DNA is known as a provirus . Scientists estimate that 8% to 9% of the