Bio 12 Chapter 28 Protists (Original Slides) 2014

8/9/2019 Bio 12 Chapter 28 Protists (Original Slides) 2014

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LECTURE PRESENTATIONS

For CAMPBELL BIOLOGY, NINTH EDITIONJane B. Reece, Lisa A. Urry, Micae! L. Cain, "#e$en A. %asser&an, Pe#er '. Minors(y, Ro)er# B. Jac(son

* +-- Pearson E/ca#ion, Inc.

Lectures by

Erin Barley

Kathleen Fitzpatric

Pr!tists

Chapter "#

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LECTURE PRESENTATIONS

For CAMPBELL BIOLOGY, NINTH EDITIONJane B. Reece, Lisa A. Urry, Micae! L. Cain, "#e$en A. %asser&an, Pe#er '. Minors(y, Ro)er# B. Jac(son


Lectures by

Erin Barley

Kathleen Fitzpatric

Pr!t!z!a 'ani(al)lie pr!tists*

Chapter "#

"$%&



The original slides in this set are from

Chapter 28 Protists and include onlythose of animal-like protists, which are

also referred to as ‘Protozoa’.

Plant-like protists are to be

taken up with Prof Roderos.

Se te(ber "$%&



Overview: Li+in, s(all

• Even a low-power microscope can reveal a greatvariety of organisms in a drop of pond water

• Protist is the informal name of the group of mostlyunicellular eukaryotes

• dvances in eukaryotic systematics have causedthe classification of protists to change significantly

• Protists constitute a polyphyletic group, and

Protista is no longer valid as a kingdom

- "$%% Pears!n E.ucati!n Inc/ Se te(ber "$%&



1 m

Figure 28.1

0hich !r,anis(s are pr!ary!tes

an. 1hich are euary!tes2

- "$%% Pears!n E.ucati!n Inc/ Se te(ber "$%&



Concept 28.1: 3!st euary!tes are

sin,le)celle. !r,anis(s• Protists are eukaryotes

• Eukaryotic cells have organelles and are more

comple! than prokaryotic cells• "ost protists are unicellular, #ut there are some

colonial and multicellular species

Se te(ber "$%&

- "$%% Pears!n E.ucati!n Inc/



Structural an. Functi!nal 4i+ersity in Pr!tists

• Protists e!hi#it more structural and functional

diversity than any other group of eukaryotes

•

$ingle-celled protists can #e very comple!, as all#iological functions are carried out #y organelles in

each individual cell




• Protists, the most nutritionally diverse of alleukaryotes, include

% Photoautotrophs, which contain chloroplasts

%&eterotrophs, which a#sor# organic molecules oringest larger food particles

% Mixotrophs, which com#ine photosynthesis and

heterotrophic nutrition




•

$ome protists reproduce ase!ually,while others reproduce se!ually, or #y

the se!ual processes of meiosis and

fertilization




En.!sy(bi!sis in euary!tic e+!luti!n

• There is now considera#le evidence that muchprotist diversity has its origins in endosym#iosis

• Endosymbiosis is the process in which a

unicellular organism engulfs another cell, which

#ecomes an endosym#iont and then organelle in

the host cell

• "itochondria evolved #y endosym#iosis of an

aero#ic prokaryote• Plastids evolved #y endosym#iosis of a

photosynthetic cyano#acterium




Cyanobacterium

Heterotrophic

eukaryote

Primary

endosymbiosis

Membranes

are represented

as dark lines in

the cell.

1 2

!ne o" these

membranes #as

lost in red andgreen algal

descendants.

Plastid

$ed alga

%econdary

endosymbiosis

%econdary

endosymbiosis

%econdary

endosymbiosis

&reen alga

'ino"lagellates

(picomplexans

%tramenopiles

Plastid

Euglenids

Chlorarachniophytes

Figure 28.2

'i)ersity o" plastid*bearing protists

produced by endosymbiosis

Plastid




• The plastid-#earing lineage of protists evolved into

red and green algae• The '( of plastid genes in red algae and green

algae closely resem#le the '( of cyano#acteria

• )n several occasions during eukaryotic evolution,

red and green algae underwent secondary

endosymbiosis, in which they were ingested #y a

heterotrophic eukaryote




Fi)e supergroups o" eukaryotes

• *t is no longer thought that amitochondriates+lacking mitochondria are the oldest lineage of

eukaryotes

• "any have #een shown to have mitochondria and

have #een reclassified

• )ur understanding of the relationships among

protist groups continues to change rapidly

• )ne hypothesis divides all eukaryotes +includingprotists into five supergroups




Figure 28.a'iplomonads

Parabasalids

Eugleno+oans

'ino"lagellates

(picomplexans

Ciliates

'iatoms

&olden algae

,ro#n algae

!omycetes

Cerco+oans

Forams

$adiolarians

$ed algae

Chlorophytes

Charophytes

-and plants

%lime molds

&ymnamoebas

Entamoebas

ucleariids

Fungi

Choano"lagellates

(nimals

( l )

e o

l a t e s

% t r a

m e

n o

p i l e

s

& r e

e n

a l g

a e

( m

o e b o

+ o a

n s

! p

i s t h o

k o

n t s

E x

c a

) a t a

C h r o m

a l )

e o

l a t a

$

h i + a

r i a

( r c h

a e

p l a

s t i d

a

/ n i k

o n

t a

Pro#is#an Di$ersi#y



'iplomonads

Parabasalids

Eugleno+oans

'ino"lagellates

(picomplexans

Ciliates

'iatoms

&olden algae

,ro#n algae

!omycetes

( l ) e o l a t e

s

% t

r a m e

n o

p i l e s

E x

c a

)

a t a

C h r o m

a l )

e o

l a t a

Figure 28.a




igure /.0a#

Cerco+oans

Forams

$adiolarians

$ed algae

Chlorophytes

Charophytes

-and plants

& r e

e n

a l g

a e

$ h i +

a r i a

( r c h

a e

p l a

s t i d a

Figure 28.a




%lime molds

&ymnamoebas

Entamoebas

ucleariids

Fungi

Choano"lagellates

(nimals

( m

o e b

o +

o a

n

s

! p

i s t h o

k o

n t s

/

n i k o

n t a

Figure 28.a




• The clade Exca)ata is characterized #y its

cytoskeleton• $ome mem#ers have a feeding groove

• This controversial group includes the

diplomonads, para#asalids, and euglenozoans

C!ncept "#/"5 E6ca+ates inclu.e pr!tists

1ith (!.i7ie. (it!ch!n.ria an. pr!tists1ith uni8ue 7la,ella




Figure 28./01

inetoplastids

Euglenids Eugleno+oans

'iplomonads

Parabasalids

E x

c a

) a

t

a

Chromal)eolata

$hi+aria

(rchaeplastida

/nikonta




'iplomonads and Parabasalids

• These two groups lack plastids, have modifiedmitochondria, and most live in anaero#icenvironments

• 'iplomonads

% &ave modified mitochondria called mitosomes

% 'erive energy from anaero#ic #iochemicalpathways

% &ave two e1ual-sized nuclei and multiple flagella

% re often parasites, for e!ample, Giardiaintestinalis +also known as Giardia lamblia




Figure 28.b

Giardia intestinalis a diplomonad parasite

3 m


"lagella



• Parabasalids % &ave reduced mitochondria called

hydrogenosomes that generate some energy

anaero#ically

% *nclude Trichomonas vaginalis, the pathogen that

causes yeast infections in human females




Figure 28.4

"lagella

3

m

undulatingmembrane


The parabasali. Trichomonas vaginalis 'c!l!rize. SE3*



Eu,len!z!ans

• Eugleno+oa is a diverse clade that includespredatory heterotrophs, photosynthetic autotrophs,

and parasites

• The main feature distinguishing them as a clade

is a spiral or crystalline rod of unknown function

inside their flagella

• This clade includes the kinetoplastids and

euglenids




Figure 28.3

crystalline rod

5cross section6

"lagella

ring o" microtubules

5cross section6

8 m

0.2 m

Euglenozoan flagellum




Figure 28.3a

crystalline rod

5cross section6ring o" microtubules

5cross section6

0.2 m

Euglenozoan flagellum




Kinetoplastids

• inetoplastids have a single mitochondrion withan organized mass of '( called a kinetoplast

• They include free-living consumers of prokaryotesin freshwater, marine, and moist terrestrial

ecosystems

• This group includes Trypanosoma, which causessleeping sickness in humans

• nother pathogenic trypanosome causes 2hagas’disease




Figure 28.7

m

Trypanosoma

Trypanosoma, the kinetoplastid that causes sleeping sickness




• Trypanosomes evade immune responses #yswitching surface proteins

• cell produces millions of copies of a singleprotein

• The new generation produces millions of copies ofa different protein

• These fre1uent changes prevent the host from

developing immunity




Euglenids

• Euglenids have one or two flagella that emergefrom a pocket at one end of the cell

• $ome species can #e #oth autotrophic and

heterotrophic




Figure 28.9

long "lagellum

eyespot

short "lagellum

contractile )acuole

nucleus

chloroplasts

plasma membrane

Euglena 5-M6

3 m

pellicle

lightdetector




igure /.3a

-ong "lagellum

Eyespot

Contractile )acuole

ucleus

Chloroplast

Plasma membrane

Euglena 5-M6 3 m




Concept 28.35 Chr!(al+e!lates (ay ha+e

!ri,inate. by sec!n.ary en.!sy(bi!sis• $ome data suggest that the clade

Chromal)eolata is monophyletic and originated

#y a secondary endosym#iosis event

• The proposed endosym#iont is a red alga

• This clade is controversial and includes the

alveolates and the stramenopiles




Figure 28./02

(picomplexans

Ciliates

'iatoms

%tramenopiles

(l)eolates

C h r o m

a l )

e o l a

t a

$hi+aria

(rchaeplastida

/nikonta

'ino"lagellates

&olden algae

,ro#n algae

!omycetes

Exca)ata




Al+e!lates

•"em#ers of the clade (l)eolata havemem#rane-#ounded sacs +alveoli 4ust under

the plasma mem#rane

• The function of the alveoli is unknown

• The alveolates include

% 'inoflagellates

% picomple!ans

% 2iliates




Figure 28.8

"lagellum al)eoli

(l)eolate

0 . 2

m

Al+e!li are sacs un.er the plas(a (e(brane




Dinoflagellates

•'ino"lagellates have two flagella and each cell isreinforced #y cellulose plates

• They are a#undant components of #oth marine

and freshwater phytoplankton

• They are a diverse group of a1uatic phototrophs,

mi!otrophs, and heterotrophs

• To!ic 5red tides6 are caused #y dinoflagellate

#looms


igure /.7



"lagella

m

Piesteria sh!mwayae




Apicomplexans

•(picomplexans are parasites of animals, andsome cause serious human diseases

• They spread through their host as infectious cells

called sporozoites

• )ne end, the ape!, contains a comple! of

organelles specialized for penetrating host cells

and tissues

• "ost have se!ual and ase!ual stages that re1uiretwo or more different host species for completion




Figure 28.10a

mero+oite

apex

red bloodcell

0.3 m




• The apicomple!an Plasmodi!m is the parasitethat causes malaria

• Plasmodi!m re1uires #oth mos1uitoes and

humans to complete its life cycle• ppro!imately 788,888 people die each year from

malaria

• Efforts are ongoing to develop vaccines that target

this pathogen




%poro+oites 5n6

!ocyst

:ygote

52n6

Mero+oite 5n6

&ametes

-i)er

-i)er cell

$ed bloodcells

&ametocytes5n6

mero+oite

apex

0.3 mred blood cell

ey

Haploid 5n6

'iploid 52n6

;nside mos<uito ;nside human

ME;!%;%

FE$=;-;:(=;!

Figure 28.10*




Ciliates

•Ciliates, a large varied group of protists, arenamed for their use of cilia to move and feed

• They have large macronuclei and small

micronuclei

• 9enetic variation results from con>ugation, in

which two individuals e!change haploid

micronuclei

• 2on4ugation is a se!ual process, and is separatefrom reproduction, which generally occurs #y

#inary fission




Figure 28.11a

contractile)acuole

oral groo)e

cell mouth

"ood )acuoles

micronucleus

macronucleus

30 m

5a6 Feeding #aste remo)al and #ater balance


cilia

"#r/c#/re an 0/nc#ion in #e ci!ia#e Parameci!m ca!dat!m

igure /.::



Contractile)acuole !ral groo)e

Cell mouth

Food )acuoles

Cilia

Micronucleus

Macronucleus

30 m

5a6 Feeding #aste remo)al and #ater balance

Con>ugation

(sexualreproduction

ey

ME;!%;%

M;C$!/C-E($

F/%;!

'iploid

micronucleus

'iploid

micronucleus

Haploid

micronucleuscompatiblemates

=he original

macronucleusdisintegrates.

5b6 Con>ugation and reproduction




Concept 28."5 Rhizarians are a .i+erse ,r!up

!7 pr!tists .e7ine. by 4NA si(ilarities• '( evidence supports $hi+aria as a

monophyletic clade• (moebas move and feed #y pseudopodia; some

#ut not all #elong to the clade <hizaria

• <hizarians include radiolarians, forams, and

cercozoans




Figure 28./0

$adiolarians

Foramini"erans

Cerco+oans

$ h i +

a r i a

Exca)ata

Chromal)eolata

(rchaeplastida

/nikonta




Ra.i!larians

•

"arine protists called radiolarians have testsfused into one delicate piece, usually made of

silica

• <adiolarians use their pseudopodia to engulf

microorganisms through phagocytosis

• The pseudopodia of radiolarians radiate from the

central #ody




Figure 28.18

Pseudopodia

200 m


A ra.i!larian



F!ra(s

•

Foramini"erans, or "orams, are named forporous, generally multicham#ered shells, called

tests

• Pseudopodia e!tend through the pores in the test

• oram tests in marine sediments form an

e!tensive fossil record

• "any forams have endosym#iotic algae




Globigerina a "oram in the supergroup $hi+aria

100 m

Figure 28.d




Cerc!z!ans

•

Cerco+oans include most amoe#oid andflagellated protists with threadlike pseudopodia

• They are common in marine, freshwater, and soil

ecosystems

• "ost are heterotrophs, including parasites and

predators






Figure 28.1

chromatophore

3 m


second case of primary endosym#iosis=



Concept 28.#: Uni!nts inclu.e pr!tists that

are cl!sely relate. t! 7un,i an. ani(als• The supergroup /nikonta includes animals, fungi,

and some protists

• This group includes two clades> the amoe#ozoans

and the opisthokonts +animals, fungi, and related

protists

• The root of the eukaryotic tree remains

controversial• *t is unclear whether unikonts separated from

other eukaryotes relatively early or late




Choano"lagellates



/nikonta

Exca)ata

Chromal)eolata

$hi+aria

(rchaeplastida

$E%/-=%

Common

ancestor

o" all

eukaryotes

'HF$*=%gene

"usion

Choano"lagellates

(nimals

Fungl

(moebo+oans

Eugleno+oans

(l)eolates

%tramenopiles

$hi+arians

'iplomonads

$ed algae

&reen algae

Plants

Figure 28.2





Figure 28."

( unikont amoeba

100 m




Gymnamoebas

•

9ymnamoe#as are common unicellularamoe#ozoans in soil as well as freshwater and

marine environments

• "ost gymnamoe#as are heterotrophic and actively

seek and consume #acteria and other protists




Entamoebas

•

Entamoe#as are parasites of verte#rates andsome inverte#rates

• &ntamoeba histolytica causes ame#ic dysentery,

the third*leading cause of human death due toeukaryotic parasites




Opisth!!nts

• !pisthokonts include animals, fungi,and several groups of protists




Concept 28.': Pr!tists play ey r!les in

ec!l!,ical c!((unities

• Protists are found in diverse a1uatic environments

• Protists often play the role of sym#iont or producer




Sy(bi!tic Pr!tists

•

$ome protist sym#ionts #enefit their hosts % 'inoflagellates nourish coral polyps that #uild

reefs

% @ood-digesting protists digest cellulose in the gut

of termites


Figure 28 27 @ood digesting protist +para#asalid in termites



Figure 28.27

1 0

m

@ood-digesting protist +para#asalid in termites




•

$ome protists are parasitic 2 Plasmodi!m causes malaria

2 Piesteria sh!mwayae is a dinoflagellate that

causes fish kills




Ph!t!synthetic Pr!tists

•

"any protists are important producers that o#tainenergy from the sun

• *n a1uatic environments, photosynthetic protists

and prokaryotes are the main producers

• *n a1uatic environments, photosynthetic protists

are limited #y nutrients

• These populations can e!plode when limiting

nutrients are added


Figure 28 29



Figure 28.29

herbi)orous

plankton

!ther consumers

carni)orous

plankton

Protistan

producersprokaryoticproducers

Protists> key producers in a1uatic communities- "$%% Pears!n E.ucati!n Inc/



• Aiomass of photosynthetic protists has declined as

sea surface temperature has increased

• *f sea surface temperature continues to warm due to

glo#al warming, this could have large effects on

% "arine ecosystems

% ishery yields % The glo#al car#on cycle


Fi 28 28



Higher

-o#er

%%=

%%=

&ro#th&ro#th;n regions bet#een the

black lines a layer o" #arm #ater

rests on top o" colder #aters.

;n the yello# regions high %%=s increase the

temperature di""erences bet#een #arm and cold

#aters #hich reduces up#elling.


Figure 28.28



Figure

28./07


Fi 28 /07



Figure 28./07a


Figure 28 /07b



Figure 28./07b




End of slides for 2hapter /

Documents

Bio 12 Chapter 28 Protists (Original Slides) 2014