Protists are single-celled organisms that can exist both as free-living organisms or as parasites. They are found in a variety of habitats, from freshwater to saltwater, from soil to the human body. While they may appear simple, protists are actually incredibly diverse and complex organisms. One way in which they differ is in the type of cellular appendages they possess. Some protists have cilia and others have flagella. Understanding the differences between these two types of appendages is key to understanding protists more fully.
Cilia vs Flagella
Cilia and flagella are both cellular appendages that protrude from the cell membrane. They are used for locomotion and to sense the environment. The main difference between cilia and flagella is in their structure and size.
Cilia are much shorter than flagella, measuring about 5-10 micrometers in length. They are composed of a central core of microtubules surrounded by an outer membrane. Cilia are arranged in rows and move in a coordinated, synchronous fashion. This allows them to create a current of water that carries food and oxygen to the protist.
Flagella, on the other hand, are much longer than cilia, measuring around 50-200 micrometers in length. They are composed of a single, long, helical microtubule surrounded by a membrane. Flagella move in a whip-like motion that helps propel the protist through the water.
Protists with Cilia
- Euglena: Euglena are a type of protist that are found in freshwater and saltwater environments. They have a single, long flagellum, as well as numerous cilia. The cilia are used to help the organism move and to capture food particles.
- Paramecium: Paramecium are a type of protist that are found in freshwater environments. They have an elongated, pear-shaped body and numerous cilia that cover the surface. The cilia are used to help the organism move and to capture food particles.
- Stentor: Stentor are a type of protist that are found in freshwater environments. They have a trumpet-shaped body and numerous cilia that cover the surface. The cilia are used to help the organism move and to capture food particles.
Protists with Flagella
- Chlamydomonas: Chlamydomonas are a type of prot