Protists
By: Max Glover
What is a Protist?
A protist is a unicellular organism. They are neither plant or animals, however, they have some properties of each. There are tons of them, these are only four of the most well known.
Amoeba
An amoeba is a protist. They move with their pseudopods, or false foot. They stretch out their cytoplasm to make the pseudopods. Amoebas also use the pseudopods to surround their food and digest it. They reproduce asexually, by the way of fission. When there is not enough water for them to live in, they turn into a cyst. That is when they grow a hard shell and can survive droughts with this feature.
Parts of an Amoeba
Amoeba getting food
Youtube Video
Paramecium
Paramecium are another type of protist that moves by the cilia that covers itself. It eats microorganisms by the cilia pulling it to its oral groove. Paramecium can reproduce sexually and asexually. That is by binary fission (asexually) and conjugation (sexually). They have avoidance behavior, so if they sense danger they can escape. There are also trichocysts that squirts out a stringy substance that is like silly string.
Parts of a Paramecium
Paramecium
Look at the oral groove
Youtube Video
https://www.youtube.com/watch?v=a4aZE5FQ284
Look at the food vacuole separating from the gullet.
Euglena
The euglena has a single flagella that it moves by. Euglenas are more like a plant in the fact that they feed by photosynthesis. They reproduce by binary fission, splitting into two. Euglena have an eyespot to sense light, even on the other side of the pond they live in.
Parts of a Euglena
Stigma is the eyespot
Euglena
Look at the eyespot
Youtube Video
Volvox
The volvox is very complex. It gets food by photosynthesis. They are in large colonies from 500 to upwards of 20,000 single cells. The reproduction process is a bit of a mystery, but scientists think it is a mix of sexual and asexual reproduction.They move by two flagella that are on each individual cell and it spins around.
Volvox
The large ones are reproductive cells