© 2014 Pearson Education, Inc. 1

4.5 bya mya 1.8 bya1.5 bya1.3 bya1.2 bya 20  m 25  m (a)A 1.8-billion- year-old fossil eukaryote (b)Tappania, a 1.5-billion-year-old fossil that may represent an early alga or fungus (c)Bangiomorpha, an ancient red alga 20  m (d)Proterocladus, classified as a green alga (e)Bonneia, a vase-shaped eukaryote (f) An early member of the Ediacaran biota (g)Spriggina floundersi, an early animal with many body segments 750 mya635 mya600 mya 550 mya 535 mya 1 cm 0.5 cm 2

© 2014 Pearson Education, Inc. Cytoplasm DNA Nucleus Engulfing of aerobic bacterium Engulfing of photo- synthetic bacterium Mitochondrion Mito- chondrion Plastid Plasma membrane Endoplasmic reticulum Nuclear envelope Ancestral prokaryote Ancestral heterotrophic eukaryote Ancestral photosynthetic eukaryote 3

© 2014 Pearson Education, Inc. Cyano- bacterium Membranes are represented as dark lines in the cell. Red alga Primary endo- symbiosis Nucleus Heterotrophic eukaryote One of these membranes was lost in red and green algal descendants. Green alga Secondary endo- symbiosis Secondary endo- symbiosis Plastid Euglenids Chlorarachniophytes Stramenopiles Plastid Secondary endo- symbiosis Dinoflagellates 4

© 2014 Pearson Education, Inc. Pediastrum 5

© 2014 Pearson Education, Inc. Flagellum Cytoplasm Outer cell wall Inner cell wall Outer cell wall Cytoplasm Extracellular matrix (ECM) Chlamydomonas Gonium Pandorina Volvox 6

© 2014 Pearson Education, Inc. Individual choanoflagellate Choano- flagellates Other animals Collar cell (choanocyte) Sponges Animals OTHER EUKARY- OTES 7

© 2014 Pearson Education, Inc. Hydra Mouse “CCD” domain Choano- flagellate Fruit fly 8

© 2014 Pearson Education, Inc. Stramen- opiles Diplomonads Parabasalids Euglenozoans Excavata Alveo- lates Rhiza- rians Diatoms Brown algae Dinoflagellates Apicomplexans Ciliates Forams Cercozoans “SAR” clade Green algae Amoebo- zoans Red algae Chlorophytes Charophytes Land plants Archaeplastida Opisthokonts Unikonta Gymnamoebas Slime molds Nucleariids Fungi Choanoflagellates Animals 100  m 50  m “SAR” Clade Excavata 5  m Archaeplastida 20  m 50  m Unikonta 100  m 9

© 2014 Pearson Education, Inc. The parabasalid parasite, Trichomonas vaginalis (colorized SEM) Undulating membrane Flagella 5  m 10

© 2014 Pearson Education, Inc. Euglenozoan flagellum Ring of microtubules (cross section) Crystalline rod (cross section) 8  m 0.2  m Flagella 11

© 2014 Pearson Education, Inc. Trypanosoma, the kinetoplastid that causes sleeping sickness 9  m 12

© 2014 Pearson Education, Inc. The diatom Triceratium morlandii (colorized SEM) 40  m 13

© 2014 Pearson Education, Inc. Blade Stipe Holdfast 14

© 2014 Pearson Education, Inc. Flagellum Alveoli Alveolate 0.2  m 15

© 2014 Pearson Education, Inc. Flagella Pfiesteria shumwayae, a dinoflagellate 3  m 16

© 2014 Pearson Education, Inc. Contractile vacuole Cilia Oral groove Cell mouth Micronucleus Food vacuoles Macronucleus 50  m 17

© 2014 Pearson Education, Inc. 5  m Chromatophore 18

© 2014 Pearson Education, Inc. Bonnemaisonia hamifera 8 mm Red algae Nori 19

© 2014 Pearson Education, Inc. (a) Ulva, or sea lettuce (b) Caulerpa, an intertidal chlorophyte Multicellular chlorophytes 2 cm 20

© 2014 Pearson Education, Inc. Spores (n) Fruiting bodies (n) Emerging amoeba (n) Solitary amoebas (feeding stage) (n) ASEXUAL REPRODUCTION SEXUAL REPRODUCTION MEIOSIS FERTILIZATION Zygote (2n) Amoebas (n) Aggregated amoebas 600  m Migrating aggregate 200  m Key Haploid (n) Diploid (2n) 21

© 2014 Pearson Education, Inc. Other consumers Herbivorous plankton Carnivorous plankton Protistan producers Prokaryotic producers 22

© 2014 Pearson Education, Inc. NI SI S SP SA EA NA A EP NP Sea-surface temperature (SST) change (  C) −2.50− (a)(b) Southern (S) South Pacific (SP) Equatorial Pacific (EP) North Pacific (NP) South Indian (SI) North Indian (NI) South Atlantic (SA) Equatorial Atlantic (EA) North Atlantic (NA) Arctic (A) Chlorophyll change (mg/m 2 yr) −0.02−

© 2014 Pearson Education, Inc. 10  m 24

© 2014 Pearson Education, Inc. 0.5  m Apex Red blood cell Merozoite Liver cell Red blood cells Merozoite (n) Zygote (2n) Oocyst MEIOSIS Sporozoites (n) Inside mosquito Inside human FERTILIZATION Gametes Gametocytes (n) Key Haploid (n) Diploid (2n) 25