Chapter 28 - Book Flashcards
Chapter 28: Protists: Key Concepts
a. Most eukaryotes are single-celled organisms
b. Excavates include protists with modified mitochondria and protists with unique flagella
c. The SAR clade is a highly diverse group of protists defined by DNA similarities
d. Red algae and green algae are the closest relatives of land plants
e. Unikonts include protists that are closely related to fungi and animals
f. Protists play key roles in ecological communities
Chapter 28: Protists: Key Concepts
a. Most eukaryotes are single-celled organisms
b. Excavates include protists with modified mitochondria and protists with unique flagella
c. The SAR clade is a highly diverse group of protists defined by DNA similarities
d. Red algae and green algae are the closest relatives of land plants
e. Unikonts include protists that are closely related to fungi and animals
f. Protists play key roles in ecological communities`
a diverse, mostly unicellular group of eukaryotes
protists
T/F Most eukaryotes are:
a. single-celled organisms
b. multi-celled organisms
c. neither
a. most eukaryote are single-celled organisms
In what domain are protests classified as part of?
Eukarya
Unlike the cells of prokaryotes what do eukaryotic cells (including protists) have?
nucleus
membrane-bound organelles
You look at a prokaryotic cell under a microscope. Would you expect it to have a well-developed cytoskeleton?
No, because Eukaryotes have a well-developed cytokeleton (not prokaryotes)
Eukaryotic cells have a structural support that enables them have asymmetric forms and change in shape as they feed, move, or grow. What is this mainly due to?
Eukaryotes have a well-developed cytoskeleton
“Most organisms in eukaryotic lineages are _______ and most protists are _____.”
protists, unicellular
T/F Protists exhibit more structural and functional diversity than the eukaryotes with which we are most familiar–plants, animals, and fungi.
True
If you discover a new type of protist, is it more likely to be a unicellular or multicellular organism? Why?
Unicellular (most protists are unicellular)
Do protists (Domain Eukarya) have membrane-bound organelles and a nucleus?
Yes
You discover a protist that combines photosynthesis and heterotrophic nutrition. What is this protist classified as?
Mixotroph (combine photosynthesis and heterotrophic nutrition)
You find a unique protist which absorbs organic molecules and ingests large food particles. What is this protist classified as?
Heterotroph
What are highly varied among protists? In regards to nutrition, are protists very diverse?
reproduction and life cycles, yes
T/F all three basic types of sexual life cycles are represented among protists
True
Has kingdom Protista been abandoned? When is the term only used, now?
Yes, Protist only refers to eukaryotes that are not plants, animals or fungi (convenient)
What gave rise to the enormous diversity of protists that exist today?
Endosymbiosis
A certain organism lives inside the cells or cells of another organism. What is this an example of?
Endosymbiosis
“A defining moment in the origin of eukaryotes occurred when a host cell engulfed a bacterium that would later become an organelle found in all eukaryote–the mitochondrion.” What is this process an example of?
Endosymbiosis
Archaeplastida, Unikonta, and Excavata are three of the “supergroups” of eukaryotes on earth. Which supergroup is missing?
“SAR Clade”
You find a eukaryotic species with an hollowed out groove on one side of the cell body. What supergroup in Domain Eukarya does this species belong to?
Excavata
There are three major branches of living organisms (excluding viruses). Name them.
Eukarya, Archaea, Bacteria
You find a parasite that looks almost exactly like the parasite Giardia. What sub-category and supergroup of Domain Eukarya might it belong to?
Diplomonad, Excavata
List the three subgroups of the supergroup Excavata in the domain Eukarya
Diplomonads
Parabasalids
Euglenozoans
This parasite inhabits the intestines of mammals. It can infect people when they drink water contaminated with feces containing this parasites’ cysts. Drinking such can cause severe diarrhea. Boiling the water kills the parasite. What is this parasite and its categorization?
Giardia intestinalis, diplomonad parasite, supergroup Excavata, domain Eukarya
List the nine subcategories of “SAR” Clade - Eukarya
Diatoms Golden Algae Brown Algae Dinoflagellates Apicomplexans Ciliats Forams Cercozoans Radiolarians
Name the three large and diverse clades of “SAR” clade
stramenopiles
alveolata
rhizaria
Diatoms are part of what sub-category of what supergroup in the domain Eukarya?
Stramenopiles, “SAR” Clade
These beautiful single-celled protists are important photosynthetic organisms in aquatic communities
Diatoms
You find an amoeba with a pseudopodia that is threadlike in shape. The pseudopodia is an extension that bulges from the cell to capture prey. How is this amoeba classified?
amoebas are in the rhizarian subgroup of the SAR Clade
This supergroup of eukaryotes includes red and green algae, along with land plants.
Archaeplastida
Along Bodega Bay, there is quite a bit of seaweed. What is this large algae most likely named?
multicellular red or green algae in the supergroup Archaeplastida of the domain Eukarya
You find a colonial freshwater green alga. What supergroup of Eukarya is this a part of?
Archaeplastida (chlorophyte or charophyte)
Why are Archaeplastida protists important?
They include key photosynthetic species that form the base of the food web in some aquatic communities
You find an amoeba X that has a lobe-shaped (or maybe tube-shaped, you can’t tell!) pseudopodia. You also find an amoeba Y which has a threadlike pseudopodia which it uses to move. According to pg. 591:
a. Amoeba X is part of the supergroup ______
b. Amoeba Y is part of the supergroup _______
a. Unikonta (amoebas have lobe- or tube-shaped pseudopodia)
b. SAR Clade (amoebas have threadlike pseudopodia)
Figure 28.3
Studies of eukaryotes show that a cyanobacterium was engulfed by an ancestral heterotrophic eukaryote (primary endosymbiosis). That ancestor then diversified into red algae and green algae, some of which was subsequently engulfed by other eukaryotes (secondary endosymbiosis). What did this process likely produce?
the diversity of plastids that we see in eukaryotes
What event gave rise to eukaryotes?
The descent of mitochondria from a bacterium that was engulfed by a cell from an archaea lineage = endosymbiosis.
According to Figure 28.3, the plastid bearing lineage gave rise to what two lineages of photosynthetic protists, or ____?
algae, red algae and green algae
Concept 28.2
“Excavates include protists with modified mitochondria and protists with unique flagella”
Concept 28.2
“Excavates include protists with modified mitochondria and protists with unique flagella”
If a biologist discovers a protist with a modified mitochondria or a unique flagella, what supergroup of eukaryotes is this protist a part of?
Excavata (Domain Eukarya)
T/F Most diplomonads and parabasalids (Excavata - Eukarya) are found in aerobic environments.
False. They are mostly found in anaerobic environments.
T/F Most diplomonads and parabasalids (Excavata - Eukarya) are found in aerobic environments.
False. They are mostly found in anaerobic environments.
The only eukaryotes to lack “mitochondria”
Diplomonads and Parabasalids - Excavata - Eukarya