Announcements Protists - Outline Reading: Chap. 29 • Relevant reading BEFORE lab this week: Ch. 31 I. Introduction • Bring lab atlas AND textbook to lab. A. Diversity of life styles IV. Evolutionary history • Extra credit opportunity: B. Functional classifications A. Kingdom Protista? – Salmon Summit: Wed. 11/3/10, 8-4:45 pm II. Ecological importance B. How are they related St. Luke’s Community Health Education Center to each other? A. Algae C. How did they arise? Bellingham, WA (checking on registration) B. Protozoans D. How are they related III. Life cycles to plants? A. The three basic types B. Examples
Diatom I.A. Diversity of life styles Size
1. Size 10 μm 2. Morphology 3. Motility Kelp 4. Energy sources 6 orders of magnitude!
60 m
Filamentous (Golden algae) Morphology Gradient in complexity
Unicellular (Euglena) Colonial (Pandorina)
Multicellular (kelp)
1 Crawling (pseudopodia) Cell walls – protection & support Planktonic
Amoeba Diatoms Cilia Flagella Motility Fastened
Amoeba
Paramecium Euglena Kelp No cell wall
Energy source - photoautotrophs Variation in photosynthetic pigments
Energy source - heterotrophs Ingestive feeders Absorptive feeders: decomp., parasites I.B. Functional classifications Particle feeder (Stentor) Protozoans - “animal like”
Parasite Algae - “plant-like”, i.e., photosynthetic (Trypanosoma) - Eukaryotic photosynthetic organisms that are not plants
Decomposer Mix - simple to bizarre (slime mold Don’t necessarily relate to taxonomic Physarum) (ingestive) relationships and evolutionary history Predator (Amoeba)
2 Cellular slime mold – unicellular or multicellular? Mixotroph example - Euglena Cells (n) aggregate when food is scarce Amoebae (n) Spores germinate Amoebae (n) germinate (n) from zygote from spores
SEXUAL ASEXUAL REPRODUCTION REPRODUCTION Fruiting body
Stalk
Giant cell Migrating individual (2n) (slug) (n) Two cells (n) in aggregation fuse, then consume other cells
Fig. 29.9
Algae: Base of aquatic food webs II. Ecological importance
A. Algae B. Protozoans
Starr, Fig. 37.3 - Antarctic food web Fig. 28.4
Algae: Eutrophication Algae: Toxicity - red tides, Pfiesteria
Dinoflagellates
3 Algae: Global Carbon Cycling Algae: Useful products Food Emulsifiers
http://www.laurensveganjournal.org/pictures/Sushi.jpg
Carrageenan
Smith, fig. 12.7 http://www.fitsugar.com/Should-You-Avoid-Carrageenan-1074330 http://www.danisco.com/wps/wcm/connect/www/corporate/media/news/company_news/2004/june/news_97_en.htm
Algae: mutualisms Macro-algae: Habitat Lichens - fungus plus green algae; (sometimes cyanobacteria) Corals - cnidarian + dinoflagellate
Protozoan with endosymbiotic green algae
Protozoans: Disease Plasmodium: malaria
Plasmodium: malaria
Trypanosomas: sleeping sickness
See Table 28.1 Giardia Fig. 28.13
4 A. Life cycles: the three basic III. Life cycles types (draw) A. The three basic types B. Examples 1. Gametic (animal-like) 2. Zygotic (fungus-like) 3. Sporic: alternation of generations (plant-like)
B. Examples 2. Zygotic (fungus-like) 1. Gametic (animal-like)
C&R, Fig. 13.5
Dinoflagellates Diatoms
3. Sporic (plant-like) 3. Sporic variations a. Isomorphic
Laminaria Fig. 28.22b
“Alternation of generations” Fig. 28.22a
5 3. Sporic variations b. Heteromorphic IV. Evolutionary history i. Gametophyte dominant ii. Sporophyte dominant A. Kingdom Protista? B. How are they related to each other? C. How did eukaryotic protists arise? D. How are they related to higher plants?
IV.A. Kingdom Protista? Protists are not a natural group (clade)
What’s a natural group? Monophyletic and not paraphyletic Protists are paraphyletic Any questions?
Fig. 29.1 Are protists a natural monophyletic group?
What’s paraphyletic? B. Phylogeny
How are they related to each other?
28.8
C&R Fig. 25.9
6 A tentative phylogeny of the eukaryotes A tentative phylogeny of the eukaryotes
Some have endosymbiotic algae
Fig. 29.8 Fig. 29.8 Points Points 5. Photosynthetic and non-photosynthetic phyla are often more closely 1. Based on both morphological and DNA evidence related to each other than to other phyla of similar lifestyle. 2. 7-8 main groupings of eukaryotes (Discicristata Æ Excavata; 6. Many taxa are not included in this figure - either not presented in the text Cercozoa = Rhizaria); 2 of which include plants and or phylogeny is still too tentative. fungi/animals
C. How did Protists arise? Mitochondrial and Chloroplast DNA Endosymbiosis?
C&R Fig 28.4 (see also Freeman 29.11 or 29.8) Origin of early eukaryotes
How did photosynthesis spread? Secondary endosymbiosis: Secondary endosymbiosis Cryptomonads
- Chlorophylls a and c - Phycobilins - otherwise known only in red algae and cyano- bacteria
C&R, Fig. 28.5 Secondary endosymbiosis
Freeman Fig. 29.16 (or 29.13)
7 Bacteria Archaea Eukarya Eukarya
Discicristata Chromalveolates Rhizaria Plantae D. How are they related to higher plants? s te y e h a s p lg e o a t a e a i e la x a r n t e s l le s e h y a t s e te lg if c h e g n ia a id g p e s a n a p a l la r e n s a m i r lg a e a e fl o c m n a o p t h le t y o w m r c a n d c c g ia o ic m t ra lo u d e n a r u il in p o ia ro o h la e re a B A E C D A O D B F C G R G L
Secondary endosymbiosis: A green algal chloroplast Primary (initial) was transferred to the endosymbiosis: ancestor of the euglenids and occurred here to the chlorarachniophytes Secondary endosymbiosis: A red algal chloroplast was transferred to the ancestor of the chromalveolates
29.17 – Photosynthesis in protists arose by primary endosymbiosis, and spread by secondary endosymbiosis
Green algae and plants Algae are eukaryotic photosynthetic organisms that End here are not plants. So, what are the defining characteristics of plants? - Alternation of generations (sporic life cycle) - Chlorophyll a and b - Starch as a storage polymer - Cell walls of cellulose (plus other polymers) - rosette cellulose synthesizing compounds - peroxisome enzymes - phragmoplast
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