Chapter 28: Protists (2) Flashcards
Explain how mixotrophic nutrition work.
Mixotrophs - perform photosynthesis in the
presence of sunlight but switch to heterotrophic nutrition absorbing organic
nutrient from the environment.
What are the characteristics of euglenids?
- Euglenids have one or two flagella that emerge from a pocket at one end of cell
- Some species can be both autotrophic and heterotrophic (mixotrophs)
What are the groups under chromaveolata?
The Chromaveolata clade is a diverse monophyletic supergroup comprising of two major clades:
– Stramenopiles,
– Alveolates
What are the groups under stramenopiles?
Stramenopiles include some of the most
photosynthetic organism.
e.g. diatoms, golden algae and brown algae
What are the groups under alveolates?
Alveolates include many:
* photosynthetic species and
* important pathogens e.g. Plasmodium
What are the characteristics of rhizarians?
- Rhizarians include many species of amoeba.
- Have threadlike pseudopodia
What do most stramenopiles have?
- Most have a “hairy” flagellum paired with a “smooth” flagellum
What are the characteristic of diatoms?
- Diatoms are unicellular algae with a unique two-part, glass-like wall of silicon dioxide
- Diatoms are a major component of
phytoplankton and are highly diverse
Fossilized diatom walls compose
much of the sediments known as
_________.
Fossilized diatom walls compose
much of the sediments known as
diatomaceous earth
Explain diatom blooms
- After a diatom population has bloomed, many dead individuals fall to ocean floor undecomposed
- This removes carbon dioxide from the atmosphere and “pumps” it to ocean floor
What is an application of diatomaceous earth?
Diatomaceous earth is used in industries as
filtration aid, abrasive, adsorbent, stabilizer,
thermal insulator and filler
What are the characteristics of golden algae?
- Most golden algae are unicellular, but some are colonial
- Golden algae are named for their colour, which results from their carotenoids
- The cells of golden algae are typically biflagellated, with both flagella near one end
- Nutrition: all golden algae are photosynthetic, and some are mixotrophs
What are the characteristics of brown algae?
- Brown algae are the largest and most complex algae
- All are multicellular, and most are marine
– Brown algae include many species commonly called “seaweeds” - Brown algae have most complex multicellular anatomy of all algae
Giant seaweeds called ______ live
in deep parts of the ocean
Giant seaweeds called kelps live
in deep parts of the ocean.
What are the structures of kelp?
They have plantlike structures: the
rootlike holdfast anchors the algae,
and a stemlike stipe supports leaflike blades
What is the alternation of generation?
The most complex life cycles include an alternation of generations – the alternation of multicellular haploid and diploid forms
Define heteromorphic and isomorphic generations.
– Heteromorphic generations are structurally different
– isomorphic generations look similar
Explain the life cycle of brown algae.
- The diploid sporophyte produces haploid flagellated spores called zoospores
- Zoospores develop into haploid male and female gametophytes, which produce gametes
- Fertilization of gametes results in a diploid zygote, which grows into new sporophyte
What are the characteristics of alveolates and what are they divided into?
- Members of the Alveolata clade have membrane-enclosed sacs (alveoli) just under the plasma membrane
– The function of alveoli unknown
- The alveolates include
– Dinoflagellates
– Apicomplexans
– Ciliates
Explain the structure of dinoflagellates.
- have two flagella located in grooves and
- each cell is reinforced by cellulose plates
