50  m

Figure 28.1c Too diverse for one kingdom: a slime mold (Physarum polychalum)

Figure 28.4 A model of the origin of eukaryotes

Cyanobacterium Heterotrophic eukaryote Primary endosymbiosis Red algae Green algae Secondary endosymbiosis Secondary endosymbiosis Plastid Dinoflagellates Apicomplexans Ciliates Stramenopiles Euglenids Chlorarachniophytes Plastid Alveolates

Diplomonads Parabasalids Kinetoplastids Euglenids Dinoflagellates Apicomplexans Ciliates Oomycetes Diatoms Golden algae Brown algae Chlorarachniophytes Foraminiferans Radiolarians Gymnamoebas Entamoebas Plasmodial slime molds Cellular slime molds Fungi Choanoflagellates Metazoans Red algae Chlorophytes Charophyceans Plants Ancestral eukaryote Chlorophyta Plantae Rhodophyta Animalia Fungi (Opisthokonta) (Archaeplastida) Diplomonadida Parabasala Euglenozoa Alveolata Stramenopila Cercozoa Radiolaria Amoebozoa Excavata Chromalveolata Rhizaria Unikonta

Figure 28.9 Giardia lamblia, a diplomonad

Figure Trichomonas vaginalis, a parabasalid

Figure 28.3 Euglena: an example of a single–celled protist

Flagella 0.2 µm Crystalline rod Ring of microtubules

Figure 28.11x Trypanosoma, the kinetoplastid that causes sleeping sickness 9  m

Figure A dinoflagellate 3 µm Flagella

Figure 28.12x2 Swimming with bioluminescent dinoflagellates

Figure 28.14c Ciliates: Paramecium

CONJUGATION AND REPRODUCTION 3 Two rounds of cytokinesis partition one macronucleus and one micronucleus into each of four daughter cells. 9 The original macro- nucleus disintegrates. Four micronuclei become macronuclei, while the other four remain micronuclei. 8 Three rounds of mitosis without cytokinesis produce eight micronuclei. 7 Micronuclei fuse, forming a diploid micronucleus. 6 The cells separate. 5 The cells swap one micronucleus. 4 Three micronuclei in each cell disintegrate. The remaining micro- nucleus in each cell divides by mitosis. Meiosis of micronuclei produces four haploid micronuclei in each cell. 2 Two cells of compatible mating strains align side by side and partially fuse. 1 MICRONUCLEAR FUSION Diploid micronucleus Haploid micronucleus MEIOSIS Compatible mates Key Conjugtion Reproduction Macronucleus

Smooth flagellum Hairy flagellum 5 µm

Figure 28.16x2 Water mold: Oogonium

Figure 28.x2 Powdery mildew

Figure Diatoms: Diatom diversity (left), Pinnularia (left)

3 µm

Figure A golden alga

Figure 28.20x1 Kelp forest

Blade Stipe Holdfast

Figure The life cycle of Laminaria: an example of alternation of generations

Figure Foraminiferan

radiolarian 200 µm Axopodia

Figure Use of pseudopodia for feeding

Figure 28.29x1 Plasmodial slime mold

Figure 28.30x2 Stages of Dictyostelium

Figure Red algae: Dulse (top), Bonnemaisonia hamifera (bottom)

Figure Colonial and multicellular chlorophytes: Volvox (left), Caulerpa (right)