Final answer:
The Excavata supergroup includes three major groups: Fornicata, Parabasalia, and Euglenozoa, all known for their unique cell structures and varied metabolic capabilities.
Step-by-step explanation:
The Excavata supergroup is a classification of primitive eukaryotes, many of which are parasites, in the biological taxonomy of protists. This supergroup is primarily known for its unique cell structures and includes three major groups: Fornicata, Parabasalia, and Euglenozoa.
The Fornicata are characterized by their lack of mitochondria but presence of flagella, and they include organisms such as Giardia lamblia, a pathogen causing diarrheal illness. Parabasalia, another subgroup, often live as endosymbionts in animal guts, with modified mitochondria known as kinetoplastids.
They feature a unique cell structure with an undulating membrane and multiple flagella. Additionally, members of the Euglenozoa group display a significant variation in metabolic capabilities, with some being free-living and others parasitic.
This group includes heterotrophic predators, photosynthetic species, and parasites, with many showing modified mitochondria or chloroplasts that arose through secondary endosymbiosis.