Virus Reproduction: How These Microscopic Disease-Causers Replicate

Viruses are curious things in nature. They are so bizarre that some scientists doubt they even fit the qualifications of a living thing. However, they are so pervasive in nature and our everyday lives that they are still vastly important alive or not alive. Virus reproduction is one of the most interesting features of these microscopic anomalies, and is responsible for their success on earth.

Before going into virus reproduction, it is important to know what a virus exactly is. Most viruses are slightly larger than proteins, which are slightly larger than atoms. This means that viruses are vastly smaller than even the smallest bacteria. Although virus structure varies from type to type, most viruses contain genetic material in the form of RNA or DNA encased in a protein coat. The virus then has projections responsible for its mobility such as tail fibers or primitive types of cilia. For brevity's sake, we will focus on what are known as complex viruses. These viruses have a "head" that consists of a protein covering somewhat resembling a crystal or gemstone with several flat faces. Inside this head is the virus' genetic material. A type of complex virus that infects bacteria, called a bacteriophage, possesses a distinctive "stem" joining the head and tail structures of the virus.

Now that we know the basic parts of a complex virus, we can begin to examine their method of reproduction. Viruses cannot reproduce on their own by either asexual or sexual means. Bacteria can reproduce asexually by dividing in half, and organisms like humans can reproduce sexually using specialized reproductive cells. Viruses can do neither of these things, so virus reproduction must take place some other way. In fact, the only way viruses can reproduce is by infecting a host cell. In this sense, all viruses are microscopic parasites that prey on cells in order to reproduce. Since viruses are acellular, they depend on the machinery of prokaryotic or eukaryotic cells to do their dirty work.