Protist Groups Flashcards (Excavata, SAR, Alveolates, Rhizarians)

A set of Question-and-Answer flashcards covering key traits, organisms, and groups from Excavata, SAR, Alveolates, and Rhizarians based on the notes.

Which organism is a Diplomonad characterized by two nuclei and multiple flagella?

Giardia

What mitochondrial feature is typical of Diplomonads?

They have no functional mitochondria.

Diplomonads are commonly associated with which source of infection?

Contaminated water.

Which parasite is a Parabasalid known for an undulating membrane and multiple flagella?

Trichomonas

What health issues are Parabasalids commonly associated with?

Sexually transmitted diseases; often asymptomatic.

What is a defining feature of Kinetoplastids?

A kinetoplast: an organized mass of mitochondrial DNA.

Which genus includes species that cause African sleeping sickness and Chagas disease?

Trypanosoma

What is the primary vector for Trypanosoma species?

Tsetse flies.

How do kinetoplastids evade host immune responses?

By changing surface proteins (antigenic variation).

What nutrient strategies do Euglenids (Euglenozoans) commonly use?

Mixotrophy with phagocytosis.

Where do flagella emerge in Euglenids?

From a flagellar pocket.

What is a distinguishing feature of Stramenopiles' flagella?

One hairlike flagellum paired with a smooth flagellum.

Are Stramenopiles typically photosynthetic?

Yes; many are photosynthetic.

What is a unique feature of Diatoms?

Intricate silica (glass-like) cell walls; contribute to oxygen production.

What are the major structural parts of Brown Algae?

Holdfast, stipe, and blades.

What type of cell wall do Oomycetes have?

Cellulose cell wall.

Which pathogen caused the Potato famine—Phytophthora infestans?

Oomycete Phytophthora infestans.

What defines Alveolates?

Alveoli—membrane-bound sacs beneath the cell membrane.

What are key features of Dinoflagellates?

Two flagella; cellulose plates; photosynthetic; some bioluminescent; red tides.

Which genus within Apicomplexans is responsible for malaria?

Plasmodium.

What are the characteristic features of Ciliates?

Covered in cilia; have macro- and micro-nuclei; ciliary beating.

What ecological phenomenon can Dinoflagellate blooms cause?

Red tides.

What skeletons do Radiolarians have?

Glassy silica skeletons.

What shells do Foraminiferans have?

Calcium carbonate shells; fossils form limestone deposits.

What is the habitat and role of Cercozoans?

Soil-dwelling with diverse feeding strategies; nutrient cycling.

What are the three subgroups of the SAR supergroup?

Stramenopiles, Alveolates, Rhizarians.

Which groups are encompassed by the Excavata supergroup?

Diplomonads, Parabasalids, and Euglenozoans.

Which organism is a Diplomonad characterized by two nuclei and multiple flagella?

Giardia

What mitochondrial feature is typical of Diplomonads?

They have no functional mitochondria.

Diplomonads are commonly associated with which source of infection?

Contaminated water.

Which group of protists is characterized by an undulating membrane and multiple anterior flagella, often associated with human reproductive tract infections?

Parabasalids (e.g., Trichomonas)

What health issues are Parabasalids commonly associated with?

Sexually transmitted diseases; often asymptomatic.

What unique organelle containing a large mass of mitochondrial DNA is a defining feature of Kinetoplastids?

A kinetoplast.

Which genus includes species that cause African sleeping sickness and Chagas disease?

Trypanosoma

What is the primary vector for Trypanosoma species?

Tsetse flies.

Which mechanism allows Kinetoplastids like Trypanosoma to avoid host immunity?

By changing surface proteins (antigenic variation).

Protists that exhibit mixotrophy, combining photosynthesis with phagocytosis, and possess flagella emerging from a distinct pocket belong to which group?

Euglenids (Euglenozoans)

What specific flagellar structure, consisting of one 'hairy' flagellum and one smooth flagellum, is characteristic of Stramenopiles?

The heterokont flagella arrangement.

Are Stramenopiles typically photosynthetic?

Yes; many are photosynthetic.

Which photosynthetic protists are known for their intricate, glass-like silica cell walls and significant contribution to global oxygen production?

Diatoms

Large, multicellular marine protists structurally differentiated into holdfasts, stipes, and blades are commonly known as what?

Brown Algae

Which fungus-like protists, often plant pathogens, are distinguished by their cellulose cell walls rather than chitin?

Oomycetes

Which pathogen caused the Potato famine?

Oomycete Phytophthora infestans.

What common structural feature, involving membrane-bound sacs directly beneath the plasma membrane, defines the Alveolates?

Alveoli.

Which group of photosynthetic protists is characterized by two flagella (one circumferential, one longitudinal), cellulose plates, and can cause bioluminescence or harmful algal blooms ('red tides')?

Dinoflagellates

Obligate intracellular parasites lacking motile structures in their adult forms, but possessing an apical complex for host cell penetration, are characteristic of which protist group?

Apicomplexans (e.g., Plasmodium which causes malaria)

Protists known for their dense coverings of short, hair-like appendages used for locomotion and feeding, along with distinct macro- and micro-nuclei, belong to which group?

Ciliates

Protists with elaborate, glassy silica skeletons and delicate thread-like pseudopods radiating from their central body are classified as what?

Radiolarians

Marine protists that produce multi-chambered calcium carbonate shells and whose fossilized remains contribute to limestone deposits are known as what?

Foraminiferans

What is the habitat and role of Cercozoans?

Soil-dwelling with diverse feeding strategies; nutrient cycling.

What are the three subgroups of the SAR supergroup?

Stramenopiles, Alveolates, Rhizarians.

Which protist supergroup is characterized by an 'excavated' groove on one side of the cell body and includes Diplomonads, Parabasalids, and Euglenozoans?

Excavata