Euglenozoa - euglenoids, kinetoplastids
- Euglenoids - 1 of earliest organisms w/ mitochondria
- 1/3 have chloroplasts, are autotrophic; rest are heterotrophic
- can become heterotrophic when left in the dark
- pellicle - flexible structure made up protein strips that change the organism’s shape
- reproduction through mitotic cell division (nuclear envelop stays intact)
- stigma - light-sensitive organ that helps Euglenoids move
- Kinetoplastids - has single mitochondrion in each cell
- mini/maxi circles of DNA in each mitochondrion
- trypanosomes - causes African sleeping sickness, East Coast fever, Chagas disease, leishmaniasis
- able to change antigens on glycoprotein coat to fool antibodies
- don’t infect the flies that carry them
Alveolata - dinoflagellates, apicomplexes, ciliates
- alveoli - space below plasma membrane
- Dinoflagellates - photosynthetic, w/ 2 flagella
- spins as it moves
- cellulose-like material forms plates that surround the cell
- has chlorophyll a, c, and carotenoids
- responsible for the “red tides”
- DNA not combined w/ histone proteins
- Apicomplexes - spore-forming parasites on animals
- microaerophils - cells that grow best in low-oxygen, high-carbon dioxide areas
- Plasmodium - responsible for malaria, best-known apicomplex
- Gregarines - attaches to intestines of arthropods, annelids, mollusks
- Ciliates - has large number of cilia
- heterotrophic, w/ cilia in rows or spirals around the cell
- 2 nuclei - macronuclei needed for physiological functions, micronuclei needed for sexual reproduction
- some ciliates die after a number of generations w/o sexual reproduction
- digestive pathway - gullet >> food vacuole >> cytoproct (pore in the pellicle) >> contractile vacuoles empty waste into the outside
- conjugation - sexual process where 2 ciliates exchange DNA through cytoplasmic bridge
Stramenopila/Rhodophyta - grouped together
- Stramenopila - includes brown algae, diatoms, oomycetes
- brown algae - alternation of generations; most conspicuous of seaweeds
- diatoms - photosynthetic, w/ double silica shells; moves w/ vibrating fibrils in raphes
- oomycetes - parasites or saprobes (feeds on dead organic matter); has 2 unequal flagella on spores
- responsible for the potato famine in Ireland
- Rhodophyta - red algae
- no flagella, centrioles
- uses alternation of generations
- related to green algae through chloroplast DNA, but not host DNA
Chlorophyta - green algae, ancestors of plants
- Streptophyta >> land plants
- chloroplasts have a/b chlorophylls and carotenoids (like plants)
- Chlamydomonas - most primitive green algae
- 2 flagella for mov’t
- eyespot w/ 100,000 rhodopsin molecules used to direct mov’t
- mostly haploid
- Chlorella - nonmotile, cannot form flagella
- Volvox - forms colonies in a hollow sphere shape
Choanoflagellida - common ancestor of all animals
- has single flagellum surrounded by funnel collar
- feeds on bacteria through water straining
- has surface receptor involving phosphorylation just like sponges
protists that are hard to categorize - amoebas, foraminifera, slime molds
- Amoebas - uses pseudopods for mov’t
- cytoplasmic streaming - use of cytoplasm extensions to move, eat
- can move in any direction
- Actinopoda - aka radiolarians, secretes silica exoskeletons
- Foraminifera - heterotrophic marine protists, like tiny snails
- tests - pore-studded shells
- podia - cytoplasmic projections used for mov’t/eating
- used as geological markers, indicators of oil
- slime molds - has at least 3 different lineages
- plasmodium - nonwalled, multinucleate cytoplasmic mass
- divides into lots of small mounds when lacking food
- sporangium - produces the spores
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