Download eukarya kingdom protista i

EUKARYA
KINGDOM PROTISTA I
Origin of Eukaryote: The
Endosymbiotic Theory (1960)
Pages
229, 307
Prove: Endosymbiotic

Plastid and mitochondria have their own DNA &
ribosome that are 70s not 80s

They divide in a way similar to Prokaryotes, lack
microtubules
Their DNA is circular, naked


Their ribosome are sensitive to the same
antibiotics that interfere with prokaryotes
ribosome

Evidence of symbiotic relationship between
bacteria & protists, marine invertebrates, algae
& protozoan (Fig. 12-11)

Mitochondria arose first (common to all
Meiosis & Life cycles

For meiosis see page 236
 In eukaryote a diploid stage undergo meiosis to
produce a haploid stage
 These two stages alternate in three patterns
 Gametic meiosis: most animals & some protists *
 Sporic meiosis (alternation of generations: plants &
many algae*
 Zygotic meiosis: Fungi & some algae*
Gametic Meiosis
e.g. Human & some protists
+ Gamete
Gametes
- gamete
- + - +
Meiosis (spermatogenesis)
This cell
undergo meiosis
Fertilization
Zygote
Diploid individual
Sporic Meiosis
e.g. Plants
+ Gamete
spores
- Gamete
- + - +
Meiosis
This cell
undergo meiosis
Fertilization
Zygote
Sporophyte
(Diploid individual)
Reproductive Cycles
Animals and Plants
Sporophyte
Spore
Gametophyte
Meiosis
Adult ♂
2n
1n Sperm
Adult ♀
Egg
Zygote
Embryo
Fertilization
Zygotic Meiosis
e.g. Fungi
+ Gamete
Haploid cells
- Gamete
- + - +
Meiosis
Fertilization
Zygote
Classification of the Protists

Protista is established to hold problematic species
 Each algal group must have its own evolutionary line
 Organisms of uncertain origin are paced in the
Protista
 Protista includes:
 Plant-like organisms but gametes & zygotes not
protected
 Fungi-like organisms but have flagella & lack
chitin in cell wall
 Animal-like organisms but no embryonic
development
Ecology of Aquatic Algae

Marine algae & cyanobacteria form phytoplankton
 Importance
 Important in carbon cycle (absorb ½ CO2 produced by
human activities)
 Transform CO2 into (CH2O)n & CaCO3
 Cause algal blooms (red & brown tides)
 Increase sulfur oxides in our atmosphere
Lake Neatahwanta, Fulton, NY
Euglenoids: Phylum
Euglenophyta

e.g. Euglena*
 Like green algae, have chl(a), (b) & carotenoids
suggesting a symbiotic relationship
 Only 1/3 of the phylum has chloroplast, the rest
are heterotrophic
 Euglenoids occur in freshwater rich in organic
matter
Euglena
 Reproduce by
mitosis & lengthwise
Plasmodial Slime Molds:
Phylum Myxomycota
The name mold “thought to have a relation with fungi”
 Seems to have no close relation to other organisms
 Plasmodium: amoeboid body with no cell wall*
 Phagocyte: heterotrophic

Sclerotium
Plasmogamy
Oomycetes: Phylum Oomycota
 They are not Fungi because
Cell wall has cellulose-like polymers
Chromosomes not highly condensed as in fungi
spores are flagellated
 They are saprobic, few are parasitic
 Pathogens of Coca, pineapple, tomatoes, rubber,
papayas, onions, citrus
 e.g. the genus Plasmopara*
 e.g. Phytophthora infestans (Late blight of potato)*
Downy mildew in Grapes:
Plasmopara viticola
http://www.inra.fr/Internet/Produits/HYP3/pathogene/3plavit.htm#det

Downy mildew in grapes, threaten the entire wine production in
France (introduces from the States 1870)
Late Blight of Potato
(Phytophthora infestans)
Responsible for the great famine of 1846-47 in Ireland
Dinoflagellates: Phylum Dinophyta
 Mostly
unicellular & biflagellate*
 Have chl. a, c, & carotenoid
 Important part of marine phytoplankton
 Many produce toxins (red & brown tides)
Dinoflagellates
Ceratium
http://www.microscopy-uk.org.uk/mag/artsep01/dinof2.html
Unique: flagella move
within 2 groves

Red tide in Texas Bay, Gymnodinium breve
Diatoms: Phylum Bacillariophyta
 Very
important component of phytoplankton
 Occur in huge # 30-50 m/1 cm of a submerged
rock (1/4 of total carbon fixed)
 They lack flagella & have unique shells
* Pennate diatoms: bilaterally symmetrical*
* Centric diatoms: radially symmetrical*
- Centric float better therefore more abundant
Pennate Diatoms
Diatoms: often compared to a shoe box and its lid (frustules)
Lower valve
(the box)
Upper valve (lid)
Cell wall has an outer
layer of silica (glass)
Chrysophytes: Phylum
Chrysophyta
 Have
chl(a) & (c) masked with a golden-brown
fucoxanthin (=chrysophyte)*
 Mostly unicellular or colonial; flagellated
 Found in fresh & salt water all over world
 Reproduction is asexually by zoospores
Synura sp.
http://www.spea.indiana.edu/e455-jones/synura.jpg