1. Kingdom Protista

2. KEY CONCEPTS
Protists are a diverse group of eukaryotic organisms, most of which are microscopic

3. Protista Not a really valid “Kingdom” Contains
Few real evolutionary relationships
Contains
Algae: “plant-like” protists
Protozoa: “animal-like” protists
Slime & Water molds: fungal-like protists

5. What Are Protists? “Dumping ground” kingdom Eukaryotic
Heterotrophic and/or autotrophic
Single or multicellular
Ancestors to animals, plants, fungi

6. Animal-like Protists Called Protozoans Unicellular
Require water (live in water or moist soil)
Most heterotrophic
Some photosynthetic
Most are free-living
Some parasitic

7. All Life Functions in Just One Cell
Have food and waste VACUOLES for storing and digesting food & wastes
Many are capable of MOVEMENT
RESPOND to environment – some have light sensitive eyespot
Amoeba
Paramecium

8. All Life Functions in Just One Cell
Maintain HOMEOSTASIS
Contractile Vacuoles pump out excess water
Form Protective Cysts when food or water is scarce (dormant stage with hard covering)
Contractile Vacuole Pumping

9. Plant-like Protists Photosynthetic No true roots, stems, leaves
Golden Algae
Red Algae

10. Plant-like Protists Photosynthetic No true roots, stems, leaves
Golden Algae
Green Algae
Brown Algae
Red Algae

11. Fungi-like Protists Heterotrophic Decomposers No cell walls
Slime Molds
Water Molds

12. Reproduction Reproduction Asexual: fission
Sexual: produce gametes (specialized sex cells)
Advantage: new combinations of genes from both parents (Red Queen Hypothesis)

13. Reproduction All reproduce ASEXUALLY
Binary Fission - divides into 2 identical individuals (clones)
Rapid reproductive rate

14. Some Reproduce SEXUALLY
Conjugation - Opposite mating strains pair and exchange genetic material (DNA)

15. Protist Characteristics

16. General Characteristics
Eukaryotic
Unicellular
Some may live in colonies
May be Autotrophic or Heterotrophic or Both
Some are motile
Appeared about 1.5 BYA

17. Classified into Three Main Groups
Animal-like… heterotrophs capable of locomotion
Plant-like… photosynthetic autotrophs
Fungus-like… decomposers that reproduce by spores
Some protists may exhibit both animal-like & plant-like characteristics

18. Sizes of Protists Unicellular organisms Colonies Coenocytes
microscopic
Colonies
loosely connected groups of cells
Coenocytes
multinucleate masses of cytoplasm
Multicellular organisms
composed of many cells
can get very large – some brown algae (the giant kelps) can be 100 feet in length

19. Locomotion Protozoa used to be classified according to how they move.
Ciliates use fine “hairs” called cilia
Flagellates use longer, whip-like hairs called flagella
Amoebas and their relatives use pseudopodia
Pseudopodia are also used to capture food
Sporozoans (apicomplexans) don’t have any ability to move (non-motile)

20. Importance Importance of Protists Heterotrophic protists = protozoa
Consume bacteria and other protists
Components of aquatic and soil food webs
help with recycling nutrients
Some cause disease
Malaria
Dysentery
Sleeping sickness
others

21. Interactions Protists are free-living or symbiotic
Symbiotic relationships range from mutualism to parasitism

22. Classification of Selected Medically Important Protozoa
Four groups
Mastigophora - flagellates
Sarcodina - amoebae
Ciliophora - ciliates
Apicomplexa – aka Sporozoans
Based on:
Method of motility
Mode of reproduction
Stages in the lifecycle

23. Animal-like Protists classified by method of movement

24. Phylum Rhizopoda (formerly Sarcodina) : ex. Amoeba

25. The Amoeba uses pseudopodia for locomotion.

26. The Amoeba in 3D – notice the pseudopods

28. Amoeba surround and engulf their food… the process is called phagocytosis.

29. An Amoeba eating a Paramecium.

30. Ciliophora all use cilia for movement
have many specialized structures, including mouths, anal pores, contractile vacuoles, and two nuclei (a large macronucleus and small micronuclei)
Ex. – Paramecium and Stentor

31. Phylum Ciliophora: ex. Paramecium

32. 3D view – taken by a scanning electron microscope

33. A closer look at the Cilia…. its means of locomotion

36. another Ciliate: Stentor

37. Phylum Zoomastigophora
have flagella
some species of zooflagellates have mutualistic relationships
ex.- Trichonympha digests cellulose in the guts of termites

38. Others are parasites, like Trypanosoma, which causes African Sleeping Sickness (coma).

39. Trypanosoma

40. Trypanosoma
Red Blood Cells
Trypanosoma
White Blood Cell
Tsetse Fly: carries Trypanosoma to humans; in other words, it’s a Vector

42. Phylum Sporozoa are parasites have no means of locomotion
form spores that are dispersed by one or more hosts
ex. Plasmodium, which causes malaria

43. Portions of the Life Cycle of Plasmodium vivax
It’s Vector: Anopheles Mosquito
Red Blood Cells

45. Pathogenic Flagellates: Trypanosomes
Giardia lamblia
Trichomonas vaginalis
Genus Trypanosoma
T. brucei causes sleeping sickness
T. cruzi causes Chagas disease

46. Giardia

47. Giardiasis Fecal-oral route of infection
recreational water, water, fomites, contaminated uncooked food
Symptoms normally begin 1 to 2 weeks (average 7 days) after becoming infected.
Symptoms
Diarrhea
Gas or flatulence
Greasy stools that tend to float
Stomach or abdominal cramps
Upset stomach or nausea
May lead to weight loss and dehydration
Symptoms of giardiasis may last 2 to 6 weeks.

48. Trichomonas vaginalis
A flagellate - causes Trichomoniasis, a sexually transmitted disease

49. Trichomoniasis STD Clinical Features:
Trichomonas vaginalis infection in women is frequently symptomatic. 
Vaginitis with a purulent discharge is the prominent symptom, and can be accompanied by vulvar and cervical lesions, abdominal pain, dysuria and dyspareunia. 
The incubation period is 5 to 28 days. 
In men, the infection is frequently asymptomatic; occasionally, urethritis, epididymitis, and prostatitis can occur.

51. Kissing bug
Tsetse fly
Tsetse Fly
Trypanosomes (flagellates) in blood smear

52. 25 µm
Flagellum
Red blood
cells
Trypanosome
with undulating
membrane

53. T. cruzi causes Chagas disease
Figure 5.27

54. African Sleeping Sickness
East Africa
West Africa

55. African Sleeping Sickness
Bite reaction
Parasitemia
attacks of fever which starts 2-3 weeks after the bite
CNS Stage
changes in character and personality
Terminal stage is marked by wasting and emaciation
Death results from coma, intercurrent infection or cardiac failure

57. Sarcodina (Amoebas) Pseudopods
Some have flagellated reproductive states
Asexual reproduction by fission
Two groups have an external shell
Mostly uninucleate
Usually encyst
Most free-living
Examples
Entamoeba
Foraminifera
Radiolarians

58. Figure 5.24

59. Infective Amoebas: Entamoeba
Amoebiasis caused by Entamoeba histolytica
Fourth most common protozoan infection in the world
Aka amoebic dysentery

60. Entamoeba histolytica
Figure 5.28

61. Entameoba histolytica
Causes amoebic dysentery (diarrhea) and can enter the liver, lungs, and brain

62. Naegleria fowleri

63. Foraminifera

65. More support for the theory: Living organisms that contain endosymbiotic bacteria that carry out vital functions in the cell.
Cyanophora paradoxa - has no chloroplasts; contains an endosymbiotic cyanobacterium.
Pelomyxa has no mitochondria; this amoeba depends on aerobic bacterial symbionts to carry out respiration

66. Amoebae

67. Ciliophora (Ciliated)
Trophozoites mobile by cilia
Some have cilia in tufts for feeding and attachment
Most develop cysts
Both macronuclei and micronuclei
Division by transverse fission
Most have definite mouth and feeding organelle
Show relatively advanced behavior
Majority are free-living and harmless

68. Ciliates

71. Balantidium coli Only known ciliate that is pathogenic in humans
Affects humans, other primates, and pigs which are the reservoir
Lives in the large intestine and causes diarrhea
Trophozoites can also be detected in tissue.
Collect a tissue specimen from the large intestine, by sigmoidoscopy

72. Trophozoites
Cyst

73. Most cases are asymptomatic.
Clinical manifestations, when present, include persistent diarrhea, occasionally dysentery, abdominal pain, and weight loss. 
Symptoms can be severe in debilitated persons.
Diagnosis is based on detection of trophozoites in stool specimens or in tissue collected during endoscopy. 
Repeated stool samples
Treatment
Tetracycline with metronidazole and iodoquinol as alternatives

75. Apicomplexa (Sporozoa)
Most not motile except male gametes
Complex life cycles
Produce sporozoites following sexual reproduction
Important in transmission of infections
Most form oocysts
Entire group is parasitic
Examples
Plasmodium spp.
Toxoplasma gondii
Cryptosporidium parvum

77. Mosquito - transmits the malaria parasite Plasmodium vivax (a sporozoan)
Malaria parasite in red blood cells
Parasites breaking out of red blood cells

78. Malaria

79. Toxoplasmosis

80. Toxoplasmosis
Parasite causes eye and brain damage in a baby, if untreated.
Acute infection in older children and adults may be without symptoms, cause flu like illness or enlarged lymph glands.
Latent parasite occurs very commonly in people infecting approximately a third to a half of all humans.
Can cause active disease if a person becomes immune compromised

81. Protozoan Identification and Cultivation
Shape and size of cell
Type, number, and distribution of locomotor structures
Presence of special organelles or cysts
Number of nuclei
Can be cultivated on artificial media or in laboratory animals

82. Toxoplasma gondii Clinical Features:
Generally an asymptomatic or mild self-limiting infection. 
Immunodeficient patients
brain lesions
pneumonitis
Pregnant women/infant
miscarriage; still births
cerebral palsey; seisures
mental retardation
eye infections; impaired
vision
enlarged liver and spleen

83. Cryptosporidium can be a problem in municipal water supplies.
Cryptosporidium affects humans, dogs, and cattle
Cryptosporidium can be a problem in municipal water supplies.

84. Cryptosporidium Intracellular parasite Causes diarrhea
Affects humans, cattle, sheep, dogs
No effective drug treatment for cryptosporidiosis
Antibiotics are contraindicated; supportive care only

87. Important Protozoan Pathogens

88. Phylum Foraminifera
have a protective shell or TEST, usually made of calcium carbonate
layers of tests can deposit on the ocean floor
these can form limestone and chalk, like the White Cliffs of Dover
Some species of forams are good indicators of oil deposits below

89. Cliffs of Dover

90. Plant-like Protists are classified by COLOR

91. Plant Like Protista Importance of Protists
Autotrophic protists = algae
Photosynthetic algae are the most important primary producers of the world’s freshwater and marine ecosystems
Many are microscopic
Some are huge: kelp
Few cause disease
Toxic blooms of dinoflagellates cause
Red tides
shellfish poisoning

92. Diatoms
Giant Kelp

93. Photosynthetic Producers
Energy
Photosynthesis
6 CO2 + 6H2O C6H12O6
Respiration
Energy

94. Lake Trophic Levels Bluegill 2o consumers Osprey Humans 4o consumers
Bass 3o
consumers
Zooplankton
1o consumers
Algae - producers

95. --Are thought to be the ancestors of plants--
Phylum Chlorophyta
have both chlorophyll a and b (so they are green)
have cellulose cell walls
store carbohydrates as starch
have many types of sexual reproduction
exhibit many types of organization
--Are thought to be the ancestors of plants--

96. Variations in Sexual Reproduction
Isogamous= both sperm and egg are motile and equal in size
Anisogamous= both sperm and egg are motile and differ in size
Oogamous= large, nonmotile egg and small, motile sperm

97. Variations in Sexual Reproduction

98. Phylum Chlorophyta organization
1. Unicellular
2. Filamentous
3. Colonial
4. Bi-layer

99. Unicellular Green Algae Chlamydomonas

100. Chlamydomonas

101. Filamentous Green Algae Spirogyra has spiral-shaped chloroplasts

102. another filamentous Green Algae Zygnema 2 Star-shaped chloroplasts per cells

103. a colonial Green Algae … Volvox Mother colony with Daughter colonies
Daughter Colony

104. a bi-layered Green Algae Ulva (sea lettuce)

106. Harvesting Ulva

107. Phylum Phaeophyta brown algae multicellular flagellated sperm cells
Ex.: Fucus & Kelp

108. Phylum Pheaophyta: Brown Algae… Laminaria… Kelp
Air Bladders:
Used to take blades to the surface for photosynthesis

109. Phylum Rhodophyta: Red Algae
are multicellular
contain red accessory pigments called phycobilins
gametes do not have flagella

110. Phylum Dinoflagellata
formerly known as Pyrrophyta or fire algae
have two flagella
some are bioluminescent, producing light
others produce nerve toxins
dinoflagellates are collected and concentrated in filter-feeding animals
people who eat these animals become sick

111. Phylum Dinoflagellata ex. Peridinium

112. Red Tide- results from a bloom of Peridinium

113. Phylum Bacillariophyta: Diatoms… have tests (shells) that contain silica (SiO2), or glass

114. Diatom Strew

115. Diatoms - a SEM picture

116. Phylum Euglenophyta
have one to three flagella at their leading (apical) end
have thin protein strips called pellicles wrapped over their membranes
have an eyespot that permits them to swim toward light
can become heterotrophic when there is no light

117. Euglena (arrow indicates anterior end)

118. The Euglena uses a flagella as a means of locomotion.

119. Phylum Chrysophyta
Are golden yellow
Have one or two apical flagella

120. MORE Examples of Autotrophic Protists (Algae)

121. Giant Kelp Forest

122. Desmids – a type of green algae

123. Green and golden algae
Summer

124. Tabellaria - a diatom Note the sheets of rectangular cells

125. Asterionella - a diatom

126. A chrysophyte algae – Early Spring
Dinobryon
A chrysophyte algae – Early Spring

127. Gonyaulax (another flagellate) and view of red tide

128. Fungal Like Protists

129. Habitats Most protists live in
ocean
freshwater ponds
lakes
Streams
Soil
Parasitic protists live in body fluids of hosts

130. Phylum Acrasiomycota: Cellular Slime Molds
have both fungus and protist characteristics
spores germinate into amoebas that feed on bacteria
When food is depleted, cyclic AMP is released, causing amoebas to aggregate into one unit
the crowd of amoebas form a slug that migrates
cells from the slug form a stalk with a capsule, which makes spores
spores are released, and the cycle repeats

131. Acrasiomycota Life Cycle

132. Phylum Acrasiomycota
colony & fruiting body
aggregating amoebas

133. Phylum Myxomycota: Plasmodial Slime Molds
grow as a single, spreading mass or plasmodium
feed on decaying vegetation
when the environment becomes unfavorable (no food or water), they form stalks and spore-producing capsules
haploid spores germinate into amoeboid or flagellated cells
these cells fuse to form a new diploid plasmodium

134. Myxomycota Life Cycle

135. Myxomycota

136. Phylum Oomycota are parasitic and saprophytic
form filaments, or hyphae (like fungi)
secrete enzymes into surroundings & absorb nutrients (like fungi)
filaments lack septa or cross walls resulting in many nuclei in a cell, they are coenocytic
have cell walls made of cellulose, not chitin

137. Oomycota Life Cycle
Examples:
water molds
downy mildews
white rusts

138. Leptomitus
Powdery Mildew

139. Phylum Oomycota potatoes are native to North America
they were introduced to Europe and became a staple of the diet
during the summer of 1846 most of the potato crop was destroyed by Phytophthora (an oomycota)
nearly 1,000,000 Irish people died, and 1,500,000 emigrated to other countries, like the U.S.

141. Ulcers on fish caused by Pfiesteria
Pfiesteria piscicida.
Note the long flagella

142. Evolutionary Considerations
One group of flagellates, the choanoflagellates, is thought to have given rise to the simplest animals, the sponges.