In this video we're going to talk about the various appendages that protists use for locomotion and then we're going to have some video clips for you to look at online. This is one of those lab exercises we weren't able to film. We weren't able to get the specimens in time with the pandemic and so we can't show you what we filmed ourselves but luckily they're very commonly viewed organisms and so we're able to find good video clips done by other individuals for you to watch.
But before you start, looking at those videos, let's talk about what appendages we're looking for and then what specimen you're going to be viewing in those videos. So first things first, protists are, like we said, they're single-celled eukaryotic organisms. They have a wide variety amongst them in terms of what they resemble.
Some of them look like fungi, some of them resemble more closely plants and are like photosynthetic, and some are more closely resembling a animals, the protozoans, which are really the ones that are often pathogenic. But regardless, they generally live either in aquatic environments or moist environments, whether that be in the environment or internally inside of a living organism for a parasitic protist. And they have appendages that essentially help them swim through their watery environment.
Now the protists that we have you looking at in the video, they are not pathogenic because we didn't want to bring pathogenic protists into the lab for people to look at for obvious reasons. But they still have similar appendages to what we'd see on some of the pathogenic protists. So one type of appendage that's used is something called a flagella.
Flagella are usually long. I always describe them as whip-like tails. that undulate back and forth and allow the protist to move. And usually protists will only have one or two of these and they'll be usually located towards one end of the protist.
So over here we have an image of a flagella off the back and that kind of whips back and forth and then that allows the protist to move in the direction opposite that the flagella is swaying back and forth. What you're going to look at To see a flagella is you're going to be looking at a protist called Euglena. Now Euglena is one of those protists that is kind of more plant-like, so it's photosynthetic. When you look at the little video, you're going to see that it's green in color, the chlorophyll that helps it photosynthesize. And in the video, you will be able to see they have to have a really high magnification and a lot of contrast because this flagella is really thin.
But you will see it towards the bottom half of the video, and you will see it sort of... waving back and forth in and out of the shot. Cilia is another type of appendage used for locomotion. And in terms of differentiating it from flagella, they're usually a lot shorter than in flagella.
And there's a lot more of them. So we'll just say they are very numerous, especially compared to flagella. There's all these little tiny hair-like extensions. and they tend to sort of wave back and forth really quickly to allow the organism to move. So what you're going to be looking at in terms of, sorry I'm spelling this wrong, you're going to be looking at a paramecium as an example of cilia.
There we go. It'll look like this in the video and you'll see all those little tiny extensions that are covering the entire paramecium. You'll see them waving back and forth very rapidly allowing the paramecium to swim through the water.
And then the last one are pseudopodia which I honestly think are some of the coolest ones relative to flagella and cilia. And how they're different is that both of these are fixed sort of appendages. I'll just say fixed and I'll just abbreviate appendages that are really thin and long and they stay the same shape throughout the entire time, even if they're not moving. Pseudopodia, these are sometimes called false feet and they're sort of temporary extensions.
That's by the way, pseudo means false. They're temporary extensions. that help move the organism throughout the water.
So they'll extend a part of their plasma membrane and their cytoplasm and then kind of pull themselves forward from that extension. It can also be used as a feeding mechanism. It can wrap the protist around whatever they're consuming. We're going to look at an organism called chaos that's going to have have these extensions and you'll kind of see it almost look, it looks very blob-like, I suppose, and then it'll throw out an extension and then eventually it'll pull behind it, the plasma membrane and the cytoplasm, towards the new extension, allowing it to move really slowly through the water.
Now after you've viewed each one of these, Euglena, Paramecium, and Chaos, not necessarily in that order, whatever order you want, Then you're going to view what we have listed as the unknown. Very mysterious. You're going to look at the little video clip of the unknown protist, and this is going to be your third in-class participation question. For your third in-class participation question, I want you to list which appendage you think the unknown protist is using for locomotion. Flagella, cilia, or pseudopodia.
So your third in-class participation question is going to be, which of the appendages listed above, flagella, cilia, or pseudopodia, is being used in the video clip of the unknown protist?