28 Protists Flashcards
Are protists prokaryotes or eukaryotes?
Eukaryotes
In what organisms are contractile vacuoles found?
Protists
What are organisms that perform photosynthesis and autotrophic nutrition called?
Mixotrophs
What are ‘mixotrophs’?
Organisms that perform both photosynthesis and heterotrophic nutrition.
A venus fly trap performs photosynthesis but also digested flies as a form of heterotrophic nutrition.
Based on this how can venus fly traps be described?
As mixotrophs
How did plastids arise in algae?
Probably through the intake of cyanobacteria through endosymbiosis.
What theory explains the evolution of many protists?
‘Secondary endosymbiosis’
What is the ’secondary endosymbiosis’ hypothesis?
A hypothesis that describes the possible origin of plastids in protists.
It suggests that plastids evolved from a gram-negative cyanobacterium that was engulfed by an ancestral heterotrophic eukaryote (primary endosymbiosis)
What are amitochondriate protists?
Organisms without conventional mitochondria and with fewer membrane- bounded organelles than other protist groups.
(they are believed to be a basal group)
What are micorsporidians?
A group of species that were once classed as protists but are now regarded as fungi
What are protists divided into?
Excavata, Chromalveolata, Rhizaria, Archaeplastida and Unikonta
What protist group are land plants most closely related to?
Archarplastida
What protist group are animals most closely related to?
Unikonta
What protist group are fungi most closely related to?
Unikonta
Describe organisms of the excavata group of protists?
Some members of this supergroup have an “excavated” groove on one side of the cell body.
Two major clades (the parabasalids and diplomonads) have modified mitochondria; others (the euglenozoans) have flagella that differ in structure from those of other organisms
What are parabasalids?
A clade inside the excavata group of protists.
They have modified mitochondria.
What are diplomonads?
A clade inside the excavata group of protists.
They have modified mitochondria.
What are euglenozoans?
A clade inside the excavata group of protists.
They have a unique flagellum structure
What is giardia?
A parasite that can be found in polluted drinking water. If consumed it causes diarrhoea.
What is giardia classified under?
Protists:excavata
What is chromalveolata?
A protist group that includes many photosynthetic organisms such as diatoms. It also includes brown algae
What are brown algae classified under?
Protists, chromalveolata
What are diatoms classed under?
Protists, chromalveolata
What are diatoms?
Microscopic photosynthetic protists that are in the chromalveolata group.
True or False: Fungi can be carnivorous?
True: some use their hyphae to ensnare their prey
What is rhizaria?
A group of protists that contains many (but not all the) species of amoebas.