Chapter 28 Protists Flashcards by Sarah King

Protists are classified into _________

Supergroups

How well did you know this?

Not at all

Perfectly

Describe protists

Eukaryotes
Most unicellular, some colonial, some multicellular

Polyphyletic group

More structural and functional diversity than any other group of eukaryotes

Single celled protists can be very complex

How well did you know this?

Not at all

Perfectly

What are the different modes of nutrition in protists?

heterotrophs (absorb organic molecules and ingest larger food particles)
photoautotrophs (contain chloroplast, algae and euglena)
mixotrophs (combine photosynthesis and heterotrophic nutrition)

How well did you know this?

Not at all

Perfectly

How do you protists reproduce?

Some reproduce asexually only

binary fission
schizogony

Some have sexual reproduction

sporic life cycle
gametic life cycle
conjugation

How well did you know this?

Not at all

Perfectly

Schizogony

Form of asexual reproduction in protists, Multiple mitosis (makes daughter cells called meroxoties)

How well did you know this?

Not at all

Perfectly

The exchange of genetic material between the same species, forms a temporary union, when they separate they are genetically different from the original organism

Micronuclei are exchanged

Form of sexual reproduction

Conjugation

How well did you know this?

Not at all

Perfectly

What are the four supergroups of eukaryotes?

Excavata
SAR
Archaeplastida
Unikonta

How well did you know this?

Not at all

Perfectly

The plastid-bearing lineage of protists evolved into….

Red and green algae

-the DNA of plastid genes in red algae and green algae closely resemble the DNA of cyanobacteria

How well did you know this?

Not at all

Perfectly

On several occasions during eukaryotic evolution, red and green algae underwent ___________, in which they were ingested by a heterotrophic eukaryote

Secondary Endosymbiosis

How well did you know this?

Not at all

Perfectly

The super group is characterized by its cytoskeleton

some members have a feeding groove
modified mitochondria
unique flagella

Excavata

How well did you know this?

Not at all

Perfectly

What does the supergroup excavata include?

diplomonads
parabasalids
euglenozoans

How well did you know this?

Not at all

Perfectly

Part of the supergroup excavata, Lack plastids, have modified mitochondria, and most live in anaerobic environments

two equal sized nuclei
mitosomes- reduces mitochondria and no ETC
multiple flagella
derive energy from anaerobic biochemical pathways
often parasites

Diplomonads

How well did you know this?

Not at all

Perfectly

Part of the supergroup excavata

Causes parasite giardia (uses adhesion disks that causes nutrient malabsorption)

Also includes trichonympha that inhabits the guts of termites

Diplomonads

How well did you know this?

Not at all

Perfectly

Protozoan-flagellated
fecal-oral route

Cysts (dormant) release trophozoites (metabolically active form) —> sm intestine —> attaches to wall (adhesion discs) —> inflammation, diarrhea, blacks abs of nutrients

Giardia intestinalis

How well did you know this?

Not at all

Perfectly

Part of the supergroup excavata

Hydrogenosomes (mitochondria)

reduced Mitochondria
generate some energy anaerobically

Trichomonas vaginalis

Parabasalids

How well did you know this?

Not at all

Perfectly

Name of the mitochondria in parabasalids

Releases hydrogen metabolically

Hydrogenosomes

How well did you know this?

Not at all

Perfectly

STD, causes vaginitis, strong odor, itchy, discharge, strawberry appearance on cervix, dysuria

Trichomoniasis

How well did you know this?

Not at all

Perfectly

part of the supergroup excavata

predatory heterotrophs
photosynthetic autotrophs
parasites
**Spiral or Crystalline rod of unknown function inside their flagella

Clade- kinetopladtids and euglenids

Euglenozoans

How well did you know this?

Not at all

Perfectly

Supergroup excavata

**Single huge mitochondrion called kinetoplast
Some free-living consumers of prokaryotes
parasites (trypanosoma) include sleeping sickness and Chagas’ disease (hard to treat, use bait-and-switch defense)

Euglenozoans- kinetoplastids

How well did you know this?

Not at all

Perfectly

Excavata, euglenozoans, kinetoplastids

Bait-and-switch defense

invade immune system responses by switching surface proteins
A cell produces millions of copies of a single protein
The new generation produces millions of copies of a different protein
these frequent changes prevent the host from developing immunity

Trypanosomes

How well did you know this?

Not at all

Perfectly

Parasitic disease of the nervous system that’s transmitted by the tsetse fly

Fatal if untreated do to cells being robbed of glucose

African trypanosomiasis

African sleeping sickness

How well did you know this?

Not at all

Perfectly

Parasite caused by reduviid bug “kissing bug”

Acute- Romania’s sign
Chronic-mega esophagus, megacolon, and congestive heart failure

Seen in Mexico, central and South America

American trypanosomiasis:

Chaga’s disease

How well did you know this?

Not at all

Perfectly

Supergroup excavata

Flagella that emerge from a pocket at one end of the cell

Has chloroplasts and an eyespot ti detect light

Mixotrophic

Euglenozoans- Euglenids

How well did you know this?

Not at all

Perfectly

This super group includes

stramenopiles
Alveolates
Rhizarians

The SAR clade

How well did you know this?

Not at all

Perfectly

SAR supergroup - phototrophs - most have a “hairy” flagellum paired with a “smooth” flagellum - they include diatoms, golden algae,brown algae

Stramenopiles

Supergroup SAR - largest group of eukaryotic algae - unicellular - producers in fresh and saltwater environments - unique two-part, glass-like wall of silicon dioxide - diatomaceous earth (pool filter, organic gardening)

Stramenopiles- diatoms

What are the number one producers in the ocean?

Diatoms

SAR group - yellow and brown carotenoids - cells of golden algae (typically biflagellated) - photosynthetic (some mixotrophs) - most are unicellular but some are colonial

Stramenopiles- golden algae

Supergroup SAR - largest and most complex algae - all are multicellular, and most are marine - include many species commonly called “seaweeds” - some edible by humans ex:align-thickening agent

Stramenopiles- brown algae

What group shows the most similarities to plants? ``` Giant Seaweeds call kelps live in deep parts of the ocean Structures: Holdfast- helps it adhere to surfaces Stipe- like a stem Blades- like leafs ``` Do not have the tissue and organs plants have

Brown algae

____________ generations are structurally different, while ____________ generations look similar

Heteromorphic Isomorphic

A variety of life cycles have evolved among the multicellular algae The most complex life cycles include an _____________, The alteration of multicellular haploid and diploid forms Haploid and diploid stages are multicellular

Alteration of generations

In alteration of generations, the diploid ___________ produces haploid flagellated spores called ___________ The zoospores develop into haploid male and female ___________, which produce gametes

Sporophyte, zoospores Gametophytes

In alteration of generations, fertilization of gametes results in a diploid zygote, which grows into a new __________

Sporophyte

In alteration of generations what do gametophytes produce?

Gametes!

What’s an example of alteration of generations? Their spores have flagella, called zoospores

Life cycle of brown algae

Part of the SAR supergroup Have membrane-bounded sacs (alveoli) just under the plasma membrane This Group includes - dinoflagellates - apicomplexans - ciliates

Alveolates

Part of the supergroup SAR - two flagella - each cell is reinforced by cellulose plates - abundant components of both marine and freshwater phytoplankton - they are a diverse group of aquatic phototrophs, mixotrophs, and heterotrophs These are the #2 producers in the ocean

Alveolates- dinoflagellates

Known as the toxic “red tides” Releases neurotoxins that can be fatal

Dinoflagellate blooms

part of the SAR supergroup - parasites of animals some cause serious human diseases (at least two hosts!) - spread through their hosts as infectious cells called sporozites - The Apex (contains a complex of organelles specialized for penetrating host cells and tissues) - have sexual and asexual stages that require two or more different host species for completion

Alveolates- apicomplexans

- Disease that causes malaria - Requires to host to complete its lifecycle(mosquitoes and humans) - sexual and asexual reproduction - the disease causes cells to lyse, fever, chills

Plasmodium SAR —> alveolates —> apicomplexans

Part of the SAR supergroup - named for their use of cilia to move and feed - nuclei (large macronuclei and small micronuclei) - reproduce by conjugation (results in genetic variation, two individuals exchange haploid micronuclei) sexual process

Alveolates- ciliates Ex: paramecium

Part of the SAR supergroup ***threadlike pseudopodia(for movement) -algae can live in their forams tests (porous shell)

Rhizarians (think radiate outward)

In this supergroup most are photosynthetic Includes red algae, green algae, and land plants * land plants are descended from green algae

Supergroup Archaeplastida

Supergroup archaeplastida Land plants are descended from...

Green algae

Supergroup archaeplastida * most are multicellular “seaweeds” - Red appearance due to distinctive phycoerythrin pigments - food, industrial and scientific materials (agar, carageenan) - Can grow in deep waters

Red algae

Supergroup archaeplastida Can absorb light in deep water, allows blue and green light to penetrate

Red algae

Supergroup archaeplastida - named for their grass-green chloroplasts - cells contains some type of plastids and photosynthetic pigments that are present in land plants - plants are descended from this group - wide variety

Green algae

What are the two main groups of green algae?

- chlorophytes | - charophyceans (most closely related to land plants)

Lifecycle of chlamydomonas, a unicellular chlorophyte

Supergroup that... -includes animals, fungi, and some protists -this group includes two clades: •ameobozoans •opisthokonts (animals, fungi, and related protists)

Supergroup unikonta

What two clades does the supergroup unikonta include?

Amoebozoans Opisthokonts (animals, fungi, and related protists)

Part of the supergroup unikonta - amoeba - lobe or tube-shaped, rather than threadlike, pseudopodia Include - slime molds - tubulinids - entamoebas

Amoebozoans

Unikonta —> amoebozoans What are the two types of slime molds?

Plasmodia slime molds Cellular slime molds

Unikonta —> amoebozoans - Many species brightly pigmented, usually yellow or orange - not multicellular, undivided by plasma membrane and contain many diploid nuclei - it extends pseudopodia through decomposing material, engulfing food by phagocytosis (heterotrophs)

Plasmodial slime molds

Unikonta —> amoebozoans Plasmodia slime molds Grows in a mass called __________ Mitosis but no cytokinesis (big blob)

Plasmodium

Unikonta —> amoebozoans - Form multicellular aggregate in which cells are separated by their membranes - cells feed individually, but can aggregate to form a fruiting body - these have cytokinesis, many cells together -Dictyostelium discoideum is an experimental model for studying the evolution of multicellularity

Cellular slime molds

_________________ is an experimental model for studying the evolution of multicellularity

Dictyostelium discoideum

Supergroup unikonta - unicellular - lobe or tube-shaped pseudopodia (how they move) - most are heterotrophic and actively seek and consume bacteria and other protists

Tubulinids

supergroup unikonta - parasites of vertebrae’s in some invertebrates - entamoeba histolytica causes amoebic dysentery (diarrhea with blood) - The third leading cause of human death due to eukaryotic parasites

Entamoebas

Causes amoebic dysentery (diarrhea with blood) Third leading cause of human death due to eukaryotic parasites

entamoeba histolytica

Includes animals, fungi and several groups of protists Chanoflagellate protists - features distinctive collar surrounding flagella - modern protist most related to the common ancestor of animals

Clade opisthokonts

How do protists play a role ecologically?

- are found in diverse aquatic environments - Often play the role of symbioant or producer - dinoflagellates nourish coral polyps - wood digesting protists protists digest cellulose in the gut of terminates