Protists

Question 0

Describe the nutritional diversity of protists.

Answer 0

Protists can be Photoautotrophs, heterotrophs, and mixotrophs (combine photosynthesis and heterotrophic nutrition.)

Question 1

What are protists?

Answer 1

Protists are mostly unicellular eukaryotes. They are the most functionally diverse Eukaryotes.

Question 2

What is endosymbiosis?

Answer 2

The process in which a unicellular organism engulfs another cell, which becomes an endosymbiont and then an organelle in the host.

Question 3

What is the general description of the supergroup Excavata?

Answer 3

They have am excavated feeding groove.

Question 4

Describe Diplomonads.

Answer 4

They have modified mitochondria called mitosomes, derive energy from anaerobic biochemical pathways, have two equal sized nuclei and multiple flagella, are often parasites. Excavata

Question 5

Describe Parabasalids.

Answer 5

Have reduced mitochondria called hydrogenosomes that generate some energy anaerobically. Excavata

Question 6

Describe Euglenozoans.

Answer 6

Diverse clade that includes predatory heterotrophs, photosynthetic autotrophs, and parasites. The main feature uniting them as a clade is a spiral or crystalline rod of unknown function in the flagella. Excavata

Question 7

Describe Kinetoplastids.

Answer 7

Have a single mitochondrion with an organized mass of DNA called a kinetoplast. They include free living consumers of prokaryotes in freshwater, marine, and moist terrestrial ecosystems. Excavata

Question 8

Describe Euglenids.

Answer 8

Have one or two flagella that emerge from a pocket at one end of the cell. Some species can be both autotrophic and heterotrophic. Excavata

Question 9

What two clades make up the supergroup Chromalveolstes?

Answer 9

Alveolates and alveoli.

Question 10

What is the general description of the clade Alveolates?

Answer 10

Sacs located just under the plasma membrane.

Question 11

Describe Dinoflagellates.

Answer 11

Have two flagella and each cell is reinforced by cellulose plates. They are abundant components of both marine and freshwater phytoplankton. Toxic “red tides” caused by dinoflagellate blooms. Alveolates

Question 12

Describe Apicomplexans.

Answer 12

Parasites of animals (some cause serious human disease). Spread through host as infectious cells called sporozoites. Apex contains a complex of organelles specialized for penetrating host cells and tissues. Most have sexual and asexual stages that require two or more different host species for completion. Alveolates

Question 13

Describe Ciliates.

Answer 13

A large group of protists named for their use of cilia to move and feed, have large macronuclei and small micronuclei. Genetic variation results from conjugation, in which two individuals exchange haploid micronuclei. Alveolates

Question 14

What is the general description of the clade Stramenopila?

Answer 14

They are phototrophs and heterotrophs. Have two flagella (one is hairy, the other one is smooth).

Question 15

Describe Diatoms.

Answer 15

Unicellular algae with a unique two-part, glass like wall of hydrated silica (provides protection from predators). Usually reproduce asexually. They are a major component of phytoplankton and highly diverse. Fossilized diatom walls major component of diatomaceous Earth. Stramenopila

Question 16

Describe Golden Algae.

Answer 16

Named for their color (result of yellow and brown carotenoids). Cells are typically biflagellated with Bo near one end. All are photosynthetic and some are mixotrophs. Most are unicellular but some are colonial. Stramenopila

Question 17

Describe Brown Algae.

Answer 17

Largest and most complex algae. All are multicellular and most are marine. Include many species commonly called “seaweeds” (make up kelp forests). Have the most complex multicellular anatomy of all algae. Stramenopila

Question 18

What is alternation of generations?

Answer 18

The alteration of multicellular haploid and diploid forms.

Question 19

What is the general description of Oomycetes?

Answer 19

Includes water molds, white rusts, and downy mildews. Most are decomposes or parasites. Have filaments (hyphae) that facilitate nutrient uptake. Can have great ecological impact.

Question 20

Describe Cerozoans.

Answer 20

Include most amoeboid and flagellated protist with threadlike pseudopodia. Common in marine, freshwater, and soil ecosystem. Most are heterotrophs, including parasites and predators. Rhizarians

Question 21

Describe Foramimiferans.

Answer 21

Named for porus, generally multichambered shells called tests. Pseudopodia extend through the pore. Form extensive fossil record in marine sediment. Many have endosymbiotic algae. Rhizarians

Question 22

Describe Radiolarians.

Answer 22

Marine protists with tests fused into one delicate piece (usually made of silica). Use pseudopodia to engulf microorganisms through phagocytosis. Pseudopodia radiate from the central body. Rhizarians

Question 23

Which organisms are found in the supergroup Arachaeplastida?

Answer 23

Photosynthetic descendants of some protists. Land plants are descendants of green algae.

Question 24

Describe Red Algae.

Answer 24

Color is due to phyoerythin which masks chlorophyll. Greenish red I’m shallow water. Near black in deep water. Usually multicellular. Most abundant large algae in coastal waters of the tropics. Red algae

Question 25

Describe slime molds.

Answer 25

Once thought to be fungi. Unikonta

Question 26

Describe Gymnamoebas.

Answer 26

Common unicellular amebozoans in soil and freshwater/marine ecosystems. Heterotrophic and actively seek/consume bacteria and other protists. Unikonta

Question 27

Describe Entamoebas.

Answer 27

Parasites of vertebrates and some invertebrates. Unikonta

Question 28

Describe the role of protists in an ecological community.

Answer 28

Some protists are symbionts and benefit their hosts. Others are parasitic. Many protists are important producers that obtain energy from the sun. In aquatic environments, photosynthetic protists and prokaryotes are the main producers. Biomass of photosynthetic protists has declined as sea temperature has increased.