Ch. 20 - Protists

1
Ch. 20 - Protists
2
201 The Kingdom Protista

• What Is a Protist?
• diverse group
• may include more than 200,000 species
• eukaryotes
• most protists are unicellular
• Protista, comes from Greek words meaning the
  very first
• appeared nearly 1.5 billion years ago

3
(No Transcript)
4
Classification of Protists

• classify protists according to the way they
  obtain nutrition
• heterotrophs are called animal-like protists
• produce their own food by photosynthesis are
  called plant-like protists
• obtain their food by external digestioneither as
  decomposers or parasitesare called fungus-like
  protists

5
202 Animal-like Protists Protozoans
6

• Animal-like protists were called protozoa, which
  means first animals
• heterotrophs
• four phyla of animal-like protists (distinguished
  by their means of movement)
• zooflagellates - flagella
• sarcodines - move by extensions of their
  cytoplasm (pseudopodia)
• ciliates - cilia
• sporozoans - do not move

7
Zooflagellates

• phylum Zoomastigina
• Flagella (one or two, a few have more)
• absorb nutrients through cell membrane or live
  inside other organisms
• Most reproduce asexually
• Some have a sexual life cycle (form gametes)
• Ex Trypanosoma, Leishmania, Giardia,
  Trichonympha

8
trypanosoma

• Leishmania

Giardia
Trichonympha
9
Sarcodines

• phylum Sarcodina
• heterotrophic some parasitic
• Move by pseudopods
• form food vacuoles
• Foraminiferans are abundant in the warmer regions
  of the oceans (shells of calcium carbonate
  (CaCO3)
• Heliozoans - heliozoa means sun animal
• spikes of cytoplasm, supported by microtubules,
  project from their silica (SiO2) shells

10
Foraminiferans
Amoeba
Heliozoans
Radiolaria
11
Ciliates

• phylum Ciliophora
• Heterotrophic
• use cilia for feeding and movement
• Most ciliates are free living
• Fresh or salt water
• Trichocyst small, bottle-shaped structure used
  for defense by paramecia

12
Internal Anatomy

• Cilia
• Trichocyst small, bottle-shaped structure used
  for defense by paramecia
• Macronucleus (working genes) and one or more
  smaller micronuclei (backup copy)
• Gullet indentation in one side of a ciliate
  that allows food to enter the cell
• anal pore region of the cell membrane of a
  ciliate where waste-containing food vacuoles fuse
  and are then emptied into the environment
• contractile vacuole cavity in the cytoplasm of
  some protists that collects water and discharges
  it from the cell

13
Paramecium
14
Conjugation 

• exchange genetic material
• increase in genetic diversity
• sexual process

15
Sporozoans

• phylum Sporozoans
• Do not move on their own
• Parasites
• complex life cycles that involve more than one
  host

16
Animal-like Protists and Disease

• Ex malaria and African sleeping sickness
• Malaria
• 2 million people still die from malaria every
  year.
• Caused by Plasmodium (sporozoan)
• Carried by Anopheles mosquito
• infects liver cells and then red blood cells
• severe chills and fever
• Drugs and vaccines are only
• partially effective

17
(No Transcript)
18

• African sleeping sickness
• Caused by Zooflagellates of the genus
  Trypanosoma
• Carried by tsetse fly
• chills and rashes, can infect nerve cells

19

• Amebic dysentery
• severe diarrhea
• Caused by Entamoeba
• Found in contaminated drinking water
• Common in areas with poor sanitation
• also found in ponds and streams

20
203 Plantlike Protists Unicellular Algae

• Photosynthetic, often motile
• Often called algae
• Base of the ocean food chain
• Use chlorophyll and accessory pigments
• 4 phyla of unicellular algae
• Euglenophytes
• Chrysophytes
• Diatoms
• Dinoflagellates

21
Euglenophytes

• 2 flagella
• No cell wall
• Eyespot helps the organisms sense light
• Pellicle tough and flexible cell membrane,
  folded like a ribbon

22
Chrysophytes

• yellow-green algae and the golden-brown algae
• cell walls of some chrysophytes contain the
  carbohydrate pectin instead of cellulose
• store food in the form of oil rather than starch

23
Diatoms

• Among the most abundant and beautiful organisms
  on Earth
• produce thin, delicate cell walls rich in silicon
  (Si)the main component of glass
• shaped like the two sides of a petri dish or flat
  pillbox, with one side fitted snugly into the
  other

24
Dinoflagellates

• half are photosynthetic half live as
  heterotrophs
• two flagella
• Many species are luminescent

25
Algal Blooms 

• absorb organic material
• vital role in recycling sewage and other waste
  materials
• Can grow very fast when nutrients are abundant
• red tide
• Produce a deadly toxin
• makes shellfish
• dangerous to eat

26
204 Plantlike Protists Red, Brown, and Green
Algae

• multicellular
• Often called seaweed
• most important differences among these phyla
  involve their photosynthetic pigments
• 3 phyla
• Red algae
• Brown algae
• Green algae

27
Red Algae

• live at great depths due to their efficiency in
  harvesting light energy
• Color green, purple, red, black

28
Brown Algae

• largest and most complex of the algae
• cool, shallow coastal waters
• giant kelp sargasso sea

29
Green Algae

• Cellulose cell walls
• Share common ancestors of modern land plants

Chlamydomonas
30
Human Uses of Algae

• major food source
• Produce oxygen

31
205 Fungus-like Protists

• Heterotrophs
• damp, nutrient-rich environments and absorb food
  through their cell membranes
• Recycle organic wastes
• No chitin
• Three groups
• cellular slime molds
• acellular slime molds
• water molds

32
(No Transcript)
33
Slime mold movies

• http//employees.csbsju.edu/ssaupe/images/Movies/s
  lime20mold.avi
• http//employees.csbsju.edu/ssaupe/images/Movies/s
  lime20mold2.avi
• http//cosmos.bot.kyoto-u.ac.jp/csm/movies2/Pp_pla
  te_ss.avi
• http//cosmos.bot.kyoto-u.ac.jp/csm/movies2/Dd_cul
  _1s.avi

34
Ch. 21 - Fungi
35
211 The Kingdom Fungi  

• What Are Fungi?
• over 100,000 species
• eukaryotic heterotrophs
• cell walls made of chitin
• digest food outside of their bodies and then
  absorb it
• Some live as parasites
• reproduce both asexually and sexually
• Spread by forming spores

36
Structure of Fungi
37
Types of Fungi
Yeast
Black Bread Mold
Club Fungi
Sac Fungi
38
Facts

• Some are edible, some poisonous
• Penicillium notatum grows on plants and is used
  as an antibiotic
• Oldest fossil 460 million years ago
• Many fungi are saprobes - organisms that obtain
  food from decaying organic matter
• Some fungi are carnivorous
• Some cause plant and animal diseases

39
Penicillin fungi
Carnivorous Fungi
Poisonous Fungi
40
Fungal Diseases
41
Fungi as Decomposers

• essential role in maintaining equilibrium in
  nearly every ecosystem
• recycle nutrients by breaking down the bodies and
  wastes of other organisms

42
(No Transcript)