Chapter 28 terms/concepts/protists Flashcards
How are protists nutritionally diverse?
The are photoautotrophs, heterotrophs, and mixotrophs, which combine photosynthesis and heterotrophic nutrition
Where did protist diversity come from?
Endosymbiosis
Endosymbiosis in Eukaryotic Evolution
Heterotrophic eukaryote engulfs a cyanobacteria and the cyanobacteria evolves, forming plastid organelles and diverging red and green algae. Red and green algae are then enveloped by another hetertrophic eukaryote and give rise to eukaryotic organisms
4 supergroups of eukaryotes
- Excavata
- SAR
- Archeoplastida
- Unikonta
Excavata (general characteristics)
Defined by a feeding groove, modified mitochondria, and unique flagella
Three monophyletic groups of Excavata (and their general characteristics, and an example of the first Excavata)
Diplomonads and Parabasalids (which lack plastids and have modified mitochondria and live in anaerobic environments) - in example of diplomonads is Giardia intestinalis (a parasite that causes a diarrheal disease).
Euglenozoans , which are predator heterotrophs, autotrophs (photosynthesis) a mix of both (mixotrophs) and parasites. Their main feature is a spiral/crystalline rod inside their flagella
SAR super group include:
- Stramenopiles
- Alveolates
- Rhizarians
General characteristics and subcategories of stramenopiles
Very important photosynethetic organisms
Most have “hairy” and “smooth” flagellum - the hairy one is longer than the smooth one
They include diatoms, golden algae, and brown algae
General features of Diatoms
(Stramenopile) Unicellular algae with a unique two-part, glass like wall of silicon
They are a major component of phytoplankton and are incredibly diverse, and help remove carbon from the atmosphere
General features of Brown algae
(Stramenopile) Largest, most complex algae. Multicellular and most are marine. Include many seaweeds
Have leaflike blades, stem-like stipes, and root-like holdfasts
General characteristics of Alveolates
Membrane-enclosed sacs (alveoli) just under the plasma membrane
Apicomplexans
Subgroup of alveolates that are mostly parasitic, some cause serious human diseases
Draw the life cycle of the Plasmodium parasite
draw
General characteristics of Rhizarians
Many Rhizarians are ameobas
They have pseudopodia which are extensions of the cell surface, but rhizarian ameobas have differing pseudopodia in that they are thread-like
General features of red algae
(Supergroup Archeoplastida) Have a accessory pigment phycoerythrin that masks the green of chlorophyll
Color can vary from greenish-red in shallow water to dark red/almost black in deep water - this is due to algae absorbing light at different wavelengths
Multicellular and large
Most abundant large algae in coastal waters
General features of green algae
They are a paraphyletic group
two main groups are charophytes and the chlorophytes, and charophytes are the most closely related to plants
Alternation of generations of Chlamydomonas
draw life cycle
Heteromorphic
Structurally different generations
Isomorphic
Structurally similar generations
Sporophyte
Diploid generation in the alternation of generations, which produce haploid spores (zoospores)
Gametophyte
Zoospores that have developed into a haploid generation, produce gametes via mitosis
The fertilization of gametes creates a diploid zygote and thus a new sporophyte
Volvox
(Archeaoplastida) colonial green algae
Charophytes
Green algae that are the closest relatives of land plants
Chlorophytes
Green algae that live in freshwater but can be marine as well, live in damp soil, others live in snowy environments, some live symbiotically with fungi to form lichens (leaflike growth on rocks)
