What is the Difference Between Flagella and Sarcodina

The main difference between flagella and Sarcodina is that flagella are a structure used for the locomotion of protozoans whereas Sarcodina is a subphylum of protozoa that use pseudopodia for the locomotion.

Flagella and Sarcodina are two types of locomotion used by protozoans. Mastigopora is the taxonomic group of protozoa that uses flagella.

Key Areas Covered

1. What are Flagella
   • Definition, Characteristics, Importance
2. What is Sarcodina
   • Definition, Characteristics, Importance
3. Similarities Between Flagella and Sarcodina
   • Outline of Common Features
4. Difference Between Flagella and Sarcodina
   • Comparison of Key Differences

Key Terms

Flagella, Sarcodina, Archaeal Flagella, Bacterial Flagella, Eukaryotic Flagella

What are Flagella

Flagella are thread-like structures that the unicellular organisms of both prokaryotes and eukaryotes use for their locomotion. Generally, there are three types of flagella: bacterial flagella, archaeal flagella, and eukaryotic flagella. Bacterial flagella are helical filaments with a rotary motor and the bacterial flagella can turn clockwise or counterclockwise. Although archaeal flagella also have a rotary motor, they have features different from bacterial flagella. Meanwhile, eukaryotic flagella are complex cellular projections that lash back and forth. Normally, eukaryotic flagella occur in plants, animals, and protists. Eukaryotic flagella contain the 9+2 axenome structure.

Figure 1; Protozoa Locomotion

Furthermore, protozoa have eukaryotic flagella. Protozoans with flagella are classified into a different taxonomic group within the Phylum Sarcomastigophora. More importantly, there are three types of protozoans according to their locomotion. They are Mastigopora, Sarcodina, and Ciliophora. Mastigopora is the protozoan with flagella. Sarcodina is the protozoa with pseudopodia while Ciliophora is the protozoa with cilia for their locomotion. However, locomotion in protozoa is important to find food.  

What is Sarcodina

Sarcodina is a taxonomic group of protozoans within the Phylum Sarcomastigophora. It includes amoebas, heliozoan, rediozoa, and foraminifera, which are characterized by their ability to move by cytoplasmic flow or by pseudopods. However, according to phylogenetic studies, Sarcodina is not a monophyletic group. The key feature of the sarcodines is the locomotion by pseudopodia. Moreover, the role of pseudopodia is to trap food particles for ingestion.

Figure 2: Pseudopodia

Moreover, pseudopodia of amoeba are temporary extensions of the protoplasm. Amoeba is also free-living carnivores that engulf food by pinocytosis. However, some amoeba such as Entamoeba histolytica causes pathogenic conditions as amoeba dysentery.

Similarities Between Flagella and Sarcodina

• Flagella and Sarcodina are two types of locomotion that protozoa use to move.
• Moreover, locomotion is an important feature of protozoans as they use it for seeking food.

Difference Between Flagella and Sarcodina

Definition

Flagella refer to a slender threadlike structure, especially a microscopic appendage that enables many protozoa, bacteria, spermatozoa, etc. to swim, while Sarcodina refers to a subphylum or other taxonomic group of protozoans of the phylum Sarcomastigophora that includes protozoans forming pseudopodia.

Taxonomic Group

Mastigopora is the taxonomic group that contains protozoans using flagella for their locomotion while Sarcodina is the taxonomic group of protozoans that use pseudopodia for their locomotion.

Size of the Taxonomic Group

Moreover, fagellate protozoans are less common while Sarcodina is a large taxonomic group.

Conclusion

In brief, flagella are a thread-like structure in protozoa, important for the locomotion of protozoa. As they move, flagella lash back and forth and protozoans have eukaryotic flagella. Moreover, Mastigopora refers to protozoans with flagella. In contrast, protozoans with pseudopodia for their locomotion are a different taxonomic group known as Sarcodina. Usually, most amoebas are in the group of Sarcodina. Therefore, the main difference between flagella and Sarcodina is the type of locomotion.

References:

1. “Protozoa.” Water/Wastewater Distance Learning Website. Mountain Empire Community College.
2. “Sarcodina.” VEDANTU, Vedantu, 27 Apr. 2022.

Image Courtesy:

1. “Figure B23 02 02” By CNX OpenStax – Own work (CC BY4.0) via Commons Wikimedia
2. “Amoeba proteus with many pseudopodia ” By SmallRex – Own Work (CC BY-SA 4.0) via Commons Wikimedia