methods of classifying into a certain kingdom: 1 ... · methods of classifying into a certain...
TRANSCRIPT
CH. 22
PROTISTS
METHODS OF CLASSIFYING
INTO A CERTAIN KINGDOM:
1. prokaryote OR eukaryote
2. single OR multi celled
3. autotroph OR heterotroph
6 Kingdoms
1. Eubacteria—prokaryotes; single cell; heterotroph
2. Archaebacteria—prokaryote; single; hetero or auto
3. Protist– eukaryote; single; hetero or auto
4. Fungi—eukaryote; multi; hetero (by decomposing)
5. Plants—eukaryote; multi; auto
6. Animals—eukaryote; multi; hetero (by ingesting)
Bozeman Video--Eukarya
http://www.youtube.com/watch?v=bo0QHAS-x8A
3 types of PROTISTS:
1. animal-like (protozoans)
2. plant-like (algae)
3. fungal-like (slime molds)
Fig. 22-1, p.350
Tiny Critters, Big Impacts
Protistans are Unlike Prokaryotes
Have a nucleus and organelles
Have proteins associated with DNA
Use microtubules in a cytoskeleton,
spindle apparatus, and cilia and flagella
May contain chloroplasts
May divide by mitosis and meiosis
Difficult to Classify
Historically a catch-all kingdom
Differ enormously from one another in morphology
and life-styles
Molecular and biochemical comparisons are
clarifying the evolutionary picture
Protistans are not a monophyletic group
Giardia (a Diplomonad)
Internal parasite of humans, animals
Survives outside of body as cysts
Ingested cysts release trophozoites that attach to intestinal lining
Causes giardiasis
Fig. 22-3b, p.353
Giardia
(a Diplomonad)
Euglenoids:
Evolutionary Puzzle
Some heterotrophs
Most have chloroplasts like green algae and plants
Have flagella like flagellated protozoans
Related to flagellated protozoans
Acquired chloroplasts by endosymbiosis
Figure 22.4a
Page 354
Euglenoid Body Plan
pellicle mitochondrion Golgi body
ER
nucleus
eyespot
long flagellum
contractile vacuole chloroplast
nucleus
Fig. 22-4a, p.354
Euglenoid Body Plan
Trypanosomes (Kinetoplastids)
free flagellum
basal body
of flagellum
nucleus
mitochondrion
undulating
membrane
Trypanosoma brucei causes African
sleeping sickness
T. cruzi causes Chagas disease
Amoeboid Protozoans (Sarcodina)
Move by means of cytoplasmic streaming and pseudopods
Naked amoebas
Foraminiferans
Heliozoans
Radiolarians
Rhizopods
Actinopods
Ciliates (Ciliphora)
All heterotrophs
Arrays of cilia allow
movement and direct
food into oral cavity
Diverse life-styles
Hypotrich
Paramecium
Body Plan of Paramecium
food vacuole
food residues being ejected gullet cilia trichocysts (“harpoons”)
contractile vacuole filled micronucleus
macronucleus
contractile vacuole emptied
Fig. 22-7a, p. 356
Ciliate Conjugation
Most ciliates have two different nuclei
Large macronucleus
Smaller micronucleus
Micronucleus participates in sexual reproduction
(conjugation)
Partners exchange micronuclei
Fig. 22-9b, p.358
Flagellated
Protozoans
Dinoflagellates
Most are single photosynthetic cells
Important component of phytoplankton
Each has two flagella
Algal bloom is population explosion of dinoflagellates
Apicomplexans Parasitic
Complete part of the life cycle inside specific
cells of a host organism
Many have elaborate life cycles that require
different hosts
Many cause serious human disease
Malaria
Most prevalent in tropical and subtropical parts
of Africa
Kills a million Africans each year
Caused by four species of Plasmodium
Transmitted by Anopheles mosquitoes
sporozoite
sporozoites
merozoite
male gametocyte in red blood cell Fig. 22-11, p.359
Plasmodium Life Cycle
Chrysophytes (Chrysophyta)
Mainly free-living photosynthetic cells
Contain chlorophylls a, c1, and c2
Four groups:
- Golden algae - Diatoms
- Yellow-green algae - Coccolithophores
Fig. 22-12a, p.360
Chrysophytes (Chrysophyta)
Diatoms
Fig. 22-12, p. 360
Major component of
the phytoplankton
Silica shell of two
overlapping parts
Sediments rich in
diatom remains
quarried for many
uses
Brown Algae (Phaeophyta)
1,500 species
Most abundant in temperate
seas
Contain chlorophylls a and c,
and fucoxanthin
Range in size from tiny
filaments to giant kelps
Macrocystis
Fig. 22-13, p. 361
Fig. 22-13b, p.361
Brown Algae
(Phaeophyta)
Oomycotes
Large egg cell forms inside oogonium
Saprobic decomposers, parasites, pathogens
• Water molds
• Downy mildews
• White rusts
• Phytophthora
Red Algae (Rhodophyta)
4,100 species
Most abundant in tropical seas
Can grow at great depths (phycobilins)
Complex life cycles may include very different forms
Fig. 22-18, p.363
Red Algae
Green Algae (Chlorophyta)
7,000 species
Resemble plants
Chlorophylls a and b
Starch grains in chloroplasts
Cell walls of cellulose,
pectins
Ulva
Fig. 22-19b, p.364
Green Algae (Chlorophyta)
Fig. 22-19c, p.364
Green Algae (Chlorophyta)
Fig. 22-21, p.366
Amoeba