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

Heterotrophiceukaryote

Primaryendosymbiosis

Red algae

Green algae

Secondaryendosymbiosis

Secondaryendosymbiosis

Plastid

Dinoflagellates

Apicomplexans

Ciliates

Stramenopiles

Euglenids

Chlorarachniophytes

Plastid

Alv

eo

late

s

Dip

lom

on

ads

Par

abas

alid

s

Kin

eto

pla

stid

s

Eu

gle

nid

s

Din

ofl

agel

late

s

Ap

ico

mp

lexa

ns

Cil

iate

s

Oo

myc

ete

s

Dia

tom

s

Go

lden

alg

ae

Bro

wn

alg

ae

Ch

lora

rach

nio

ph

ytes

Fo

ram

inif

era

ns

Rad

iola

rian

s

Gym

nam

oeb

as

En

tam

oeb

as

Pla

smo

dia

l sl

ime

mo

lds

Cel

lula

r sl

ime

mo

lds

Fu

ng

i

Ch

oan

ofl

agel

late

s

Met

azo

an

s

Red

alg

ae

Ch

loro

ph

ytes

Ch

aro

ph

ycea

ns

Pla

nts

Ancestral eukaryote

Ch

loro

ph

yta

Pla

nta

e

Rh

od

op

hyt

a

An

imal

ia

Fu

ng

i

(Opisthokonta)(Archaeplastida)Dip

lom

on

adid

a

Par

abas

ala

Eu

gle

no

zoa

Alveolata Stramenopila Cer

cozo

a

Rad

iola

ria

Amoebozoa

Excavata Chromalveolata RhizariaUnikonta

Figure 28.9 Giardia lamblia, a diplomonad

Figure 28.10 Trichomonas vaginalis, a parabasalid

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

Flagella0.2 µm

Crystalline rod

Ring of microtubules

Figure 28.11x Trypanosoma, the kinetoplastid that causes sleeping sickness

9 m

Figure 28.12 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.

8Three rounds of mitosis without cytokinesis produce eight micronuclei.

7 Micronuclei fuse,forming a diploid micronucleus.

6

The cellsseparate.

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 haploidmicronuclei in each cell.

2Two cells of compatiblemating strains align sideby side and partially fuse.

1

MICRONUCLEARFUSION

Diploidmicronucleus

Diploidmicronucleus

Haploidmicronucleus

MEIOSIS

Compatiblemates

Key

Conjugtion

Reproduction

Macronucleus

Smoothflagellum

Hairyflagellum

5 µm

Figure 28.16x2 Water mold: Oogonium

Figure 28.x2 Powdery mildew

Figure 28.17 Diatoms: Diatom diversity (left), Pinnularia (left)

3 µ

m

Figure 28.18 A golden alga

Figure 28.20x1 Kelp forest

Blade

Stipe

Holdfast

Figure 28.21 The life cycle of Laminaria: an example of alternation of generations

Figure 28.28 Foraminiferan

radiolarian

200 µm

Axopodia

Figure 28.26 Use of pseudopodia for feeding

Figure 28.29x1 Plasmodial slime mold

Figure 28.30x2 Stages of Dictyostelium

Figure 28.22 Red algae: Dulse (top), Bonnemaisonia hamifera (bottom)

Figure 28.23 Colonial and multicellular chlorophytes: Volvox (left), Caulerpa (right)