At this stage hopefully you realize life isn’t actually all that simple to define. Let’s look at our enemy Mr. Flu Virus. Is the flu a living organism? According to the definition of life: no. The flu virus (or any virus) is not capable of reproducing on its own. Well then, you may be thinking, what about a drone bee or a mule (the offspring of a male donkey and a female horse)? Neither of these organisms can reproduce, but they are living creatures. The difference here is that they are made up of parts that meet all the requirements of biological life, including having cells that reproduce and grow. Viruses, on the other hand, don’t have any self-replicating parts: copying any part of a virus requires a host cell. Viruses must hijack the cellular machinery of the host in order to make more parts to assemble into new viral particles.
So how does that relate to the fact that there is a new flu vaccine every year? That question—and the questions about GMOs and diets—can be answered with information we will learn later in the course. So without further delay, let’s keep going!