Viruses and Their Life Cycles
Viruses challenge our definition of "living" because they're not made of cells and have no organelles. Scientists classify viruses based on three main characteristics: whether they contain DNA or RNA, the shape of their genetic makeup, and if they have a membranous envelope.
Viruses reproduce by invading cells through a lytic cycle or lysogenic cycle. In the lytic cycle, viruses immediately take over the host cell, rapidly produce new viruses, and then burst the cell to spread. This aggressive approach works quickly but is easier to detect.
The lysogenic cycle is sneakier! The virus integrates its genetic information into the host's DNA, creating a dormant phase. The cell treats the virus as part of its own genetic code, producing one virus at a time. This slower method is harder for the immune system to detect.
Antibiotics don't work against viruses because they only target living organisms. The word "antibiotic" literally means "against life," and since viruses aren't technically alive, these medications have no effect on them. This is why viral infections require different treatments than bacterial ones.
Think About It: Viruses are like computer hackers that can't do anything on their own but can hijack your body's cells to make copies of themselves!