In this video, we're going to introduce the 3 most common shapes of viruses. Now it turns out that viruses can actually have many different types of shapes, but the 3 most common shapes of viruses are icosahedral, helical, and complex. Now the icosahedral viruses are not perfectly spherical, but they do appear to be spherical under an electron microscope. And so they are spherical-looking viruses. But they actually consist of approximately 20 flat triangular sides. And so they give somewhat of an appearance of a soccer ball. And so notice down below on the left-hand side we're showing you the icosahedral viruses and the specific shape that they have. And so notice over here they're showing you an example of a virus that has an icosahedral shape, and that is the human rhinovirus.
Now the second most common shape that viruses can take on is the helical shape. And so these are going to be cylindrical-looking viruses whose capsids are arranged, as its name implies, in a helix. And the helix somewhat resembles a spiral staircase. And so if we take a look at our image down below in the middle, notice we're showing you a helical virus, and notice that it takes on somewhat of a spiral type of shape here, a spiral staircase. And so an example of a helical virus would be the Ebola virus.
And then the third and final most common shape of viruses are going to be complex. And so as its name implies, these viruses are going to have a variation of complicated structures. And these complicated structures can have multiple different shapes. And so an example of a complex virus could be bacteriophages or just phages. And so if we take a look at our image down below, right here on the right, notice that we're showing you a virus with a complex shape, such as a bacteriophage like what we see here. And what you'll notice is that it has components that have many different shapes, such as these legs have a specific type of shape, and the body here has a specific shape, and then, of course, the head here has a specific type of shape as well. And so when you have a variation of these complicated structures with multiple shapes, this would be a virus with a complex shape. And so once again here we're showing you an image of a bacteriophage with a complex shape.
This here concludes our brief lesson on the 3 most common shapes of viruses. And once again, we'll be able to get practice applying these concepts and learn more about viruses as we move forward in our course. So I'll see you all in our next video.
