Chapter 28: Protists Flashcards
What is a protist?
An informal term applied to any eukaryote that is not a plant, animal, or fungus
What is a Eukaryotic Cell?
A cell that has a membrane bound nucleus and membrane bound organelles
Most protists are unicellular, but some are multicellular or colonial. T or F?
T
What are the 4 types of eukaryotes?
- plants
- animals
- fungus
- protists
What protist helps termites breakdown the cellulose of wood?
Trickonympha (lives in the termite gut)
What is an example of protists that can photosynthesize?
Euglena viridis
What protist causes the red tide?
dingoflagellate
What protist causes malaria in humans?
plasmodium
What protists causes the African sleeping virus?
Trypanosome gambiense
What protist causes amebic dysentery?
Entamoeba histolytica
What was the importance of colonial protists?
living in groups lead to multicellularity
What is a volvox?
a colony of protists
What are the three types of locomotion for protists?
Flagella, Cilia, and Pseudopodia
What are flagella? What example protist uses this?
one or two extension from the cell body that propel the cell, Euglenoid
What are cilia? What example protist uses this?
many small hair like structures, Paramecium
What are pseudopodia? What example protist uses this?
“fake feet” large extensions of the cell body that can be used for locomotion or feeding, Amoeba
What are photo-autotrophs?
obtain energy through photosynthesis via chloroplasts (green coloration)
What are heterotrophs? What are the two types of protist heterotrophs?
absorb organic molecules or ingest food particles, phagotrophs and osmotrophs
What are mixotrophs?
an organism that is capable of both photosynthesis and heterotrophy
What is an example of a mixotroph?
Euglena
What are phagotrophs?
engulf food particles
What are osmotrophs?
obtain liquids
A mixotroph can only use heterotrophy if _____ is available?
light
What is more efficient in mixotrophs heterotrophy or photosynthesis?
photosynthesis
What are the 3 types of a sexual reproduction that protists use?
binary fission, budding, and schizogony
What is the basic way that binary fission works?
the cell grows to half its size and then splits
In eukaryotes does binary fission use mitosis?
yes
What is the basic way that budding works?
smaller daughter cell breaks off or parent
What is the basic way that schizogony works?
several nuclear division followed by cell division
Frequent genetic recombination generates ________ in populations
variance
What is the basis of sexual reproduction in protists?
meiosis results in haploid cells from diploid cells followed by fertilization
What is an example of a protist that uses schizogony?
plasmodia
Most protists have the capability to reproduce sexually. T or F?
T
Protists either reproduce sexually or asexually. T or F?
F, they can produce both ways
What is the common name for brown algae?
kelp
The gametophyte is quite small (few centimeters. T or F?
T
There is now considerable evidence that much of the protist diversity has origins in _______________
endosymbiosis
What did red and green algae evolve into after they acquired photosynthetic cyanobacterium?
plastids
What is a plastid?
one of a family of closely related organelles that includes chloroplasts
What are the three supporting evidences that support the idea that plastids evolved from red and green algae?
- plastid DNA resembles cyanobacteria DNA
- plastids are surrounded by two membranes
- transport proteins in membranes are homologous to membranes of cyanobacteria symbionts
What are chlorarchniophytes?
marine amen-flagellate that evolved from eukaryote engulfing algae
What was the product of secondary endosymbiosis?
chlorarachniophytes
What are is the evidence for the secondary endosymbiosis of protists?
- DNA sequence indicates they came from green algae
2. plastids are surrounded by 4 membranes in chlorarachniophytes
What is the hypothesis for plastid diversity by endosymbiosis?
That a heterotrophic eukaryote engulfed a cyanobacteria, and then was engulfed by a larger eukaryote
What is the difference between red and green algae regarding their membranes?
red algae have 3 membranes around their engulfed cyanobacterium
green algae have 2 membranes around their engulfed cyanobacteria
Primary endosymbiosis lead to the evolution of what two algae?
red algae and green algae
Secondary endosymbiosis of red algae lead to what protists?
dinoflagellates (red tide), apicomplexans (malaria), and stramenopiles (brown algae)
Secondary endosymbiosis of green algae lead to what protists?
Euglenids and chlorarachniophytes
Protists were once a single kingdom. T or F?
T
What are the 5 groups of protists?
- Excavata
- Chromaveolata
- Rhizaria
- Archaeplastids
- Unikonta
What is the common characteristic of the excavata?
they have an excavated groove on one side of the body
Giardia is an example of what group of protists?
excavata
What group of protists originated from secondary endosymbiosis? (some are photosynthetic and others are parasites)
chromaveolata
Plasmodium is an example of what group of protists?
chromaveolata
What group of protists do most amoebas with threadlike pseudopodia belong to?
rhizaria
What is the sister taxa to land plants?
green algae
Are charophytes closely related to land plants?
yes
What group of protists do amoebas with lobe shaped pseudopodia belong to?
Unikonta
What group of protists do non amoeba protists that are closely related to fungi and animals?
Unikonta
Sister taxa for fungi and animals are in what group of protists?
unikonta
What is the root meaning of Dino and how does it relate to dinoflagellates?
Dino means whirling and they relate to dinoflagellates because they have two unequal flagella
Dinoflagellates are photosynthetic. T or F?
T
Bioluminescence is due to _________?
symbiosis with bacteria
Dinoflagellates are toxic when what?
when their population explodes (like in red tide)
How many species of dinoflagellates are toxins that harm vertebrates?
20
Why are dinoflagellates are brownish or red due to presence of ___________
carotenoids
plasmodium cause _________ in humans.
malaria
complex life cycle with ______ and ________ host
mosquito, mammal
Do plasmodium use alternation of generations?
yes
What are the 4 ways that we fight/have fought malaria? What are the negative side effects of each?
- DDT: chemical used to kill mosquitos, but also thins shells, kills everything, and is detrimental to the environment
- Antimalaria Pills: prevent getting the disease, but there are side effects, they are expensive, and no good for daily use
- Tonic: was used to kill the plasmodium, but evolved and no longer has an effect
- Sterilization of male mosquitos: problem is that reducing population of mosquitos can disrupt the environment
How many people die from malaria every year?
900,000
How many people are infected by malaria each year?
250,000,000
Are plasmodia photosynthetic?
no
Do plasmodia have plastids?
yes
Human is the ________ host, and the mosquito is the _________ host
determinant, intermediate
choanoflagellates are what group of protists?
unikonta
choanoflagellates likely share common ancestry with _______
animals
sponges have ___________ __________ that exactly match the flagellated structure of these protists
flagellated cells
What are flagellate cells called?
choanocytes
Homology in _______ _______ with sponges
surface receptor