1. Kingdom Protista Learning Objectives
Explain the endosymbiotic theory and evidence supporting it
Describe identifying characteristics of the kingdom Protista
Classify the different phyla of protists
Compare and contrast the structure and function of different protists

2. Origin of Eukaryotes – Formation of Nucleus
Endomembrane infolding
Infolding of membrane system forming nucleus and ER
More surface area for material exchange with envi.

3. Eukaryotic Evolution -Endosymbiosis Hypothesis
What’s the story?
A prokaryote ingested some aerobic bacteria. The aerobes were protected and produced energy for the prokaryote. Over time the aerobes became mitochondria, no longer able to live on their own.
Some prokaryotes also ingested cyanobacteria, which can photosynthesize. Cyanobacteria became chloroplasts, unable to live on their own
Plant cell
Animal Cell

4. Scientific Evidence for Endosymbiosis theory
Membranes of chloroplasts and mitochondria are similar to those of living prokaryotes
Mitochondria and chloroplasts have their own ribosomes that more similar to prokaryotic ribosomes than ribosomes found in eukaryotes
These organelles reproduces by binary fission within the cell
Mitochondria and chloroplasts have their own DNA that match living prokaryotes’ DNA. Chloroplast genes match genes of cycnobacteria (prokaryotes)
Endosymbiosis doesn’t explain how multicellarity came about

5. Protists - General Characteristics
Most are single-celled, some multi-cellular (algae)
All are eukaryotic
Can be heterotrophic or autotrophic
Some have cell walls
Some are motile
Most live in water, some live in moist soil or even the human body 5

6. Classification and Phylogeny
Amoeba more related to elephants than to paramecia or kelp

7. Phylum name

8. 3 main groups of Protists
Characterized by how they move and get their nutrients.
Animal-like heterotrophs
Protozoa
Plant-like autotrophs
Algae
Fungi-like heterotrophs/ decomposers
Water and slime moulds 8

9. Protozoa Means “first animals” Scavengers or predators Heterotrophs
Animal-Like Protists
Protozoa
Means “first animals”
Scavengers or predators
Heterotrophs
some are parasites
Motile
Most live as single cells but others form colonies
Vary in shape and size. 9

10. Animal-Like Protists
Protozoa Phyla
Protozoa are classified into four phyla based on their methods of locomotion: 10

11. Animal-Like Protists 1. Zoomastigina (Flagellates)
one or more flagella (whip-like tail) rotate
Some are parasites, some are mutalistic symbionts or some are free-living.
Most symbionts live in digestive systems and help the host animals break down cellulose (win-win situation b/t flagellates and termite)
2. Sarcodines
the amoebae
No cell wall  can change shape
produce pseudopods (false feet) for movement and to engulf their prey (extensions of their cytoplasm)
Intestinal amoebas in human cause chronic diarrhea
Trypanosomia causes African sleeping Sickness.
Zoomastigina (Flagellates) Trichonympha : symbiont in termite gut, digests cellulose 11

12. Animal-Like Protists
Amoeba’s lunch: 12

13. 3. Ciliates/Ciliophora Ex. paramecium
Animal-Like Protists
3. Ciliates/Ciliophora
Ex. paramecium
Have cilia, tiny hair-like projections that beat together in rhythm for locomotion
Can also move food into the gullet, which leads to a food vacuole.
Balantidium coli –in human intestine Diarrhea
Gullet = a mouth take in food
Cytoproct= cell anus 13

14. 4. Sporozoans Produce spores Passive movement (none) parasites
Animal-Like Protists
4. Sporozoans
Produce spores
Passive movement (none)
parasites
Plasmodium vivax causes one type of malaria in humans. 14

15. Life Cycle of Malaria-causing Plasmodium
Watch:

16. Algae
Plant-Like Protists

17. Algae Simple, aquatic, plant-like organisms that contain chlorophyll
Plant-Like Protists
Algae
Simple, aquatic, plant-like organisms that contain chlorophyll
Lack the leaves, roots, stems and water-conducting tissues of plants
Range in size (single cells to giant seaweeds 60 m in length)
Algae - not a proper taxonomic group – there are algae in plantae & bacteria kingdom.
Classified into six different Protist “algae” phyla.
They have been on the earth for about 2 billion years and scientists are still discovering new species! 17

18. 6 Algae Phyla Major producers in food web Multicellular Plant-like
Protists
Unicellular
Plant-like
Protists
Major producers in food web 18

19. Protists in global carbon cycle
Take away message from this graph: algal bed and reefs contribute the largest % of net primary production on Earth, combining productivity in both ocean and aquatic envi. Protists play a vial role in C cycling
Photosynthetic protists, such as algae, diatoms, dinoflagellates, and euglenids, contribute to the primary productivity in the oceans and form part of the basis for major food webs in aquatic communities. For instance, as this diagram shows, algal beds and reefs have the highest estimated average net primary production as biomass per unit area of any
biomes on Earth. In addition the open ocean, because of its enormous size, contributes the largest percentage of net primary production on the Earth.
Photoautotrophic and heterotrophic protists are important members of both of these communities and, because of their sheer numbers, play integral parts in carbon cycling on the Earth.
Take away message from this graph?
algal bed and reefs contribute the largest % of net primary production on Earth, combining productivity in both ocean and aquatic envi.
Protists play a vial role in C cycling
__________________________________________________________________________________________________________________________________________
_______________________________________________________________________

20. Multicellular, Plant-Like Protists
1. Green algae (Chlorophytes)
In freshwater, even sloth’s fur
cell walls contain cellulose
Ex. Spirogyra (picture)
2. Brown Algae (Phaeophytes):
- in cold water.
- cell walls made of cellulose
- commonly called seaweeds (ex. kelp) .
- Have holdfasts to anchor body on rocky surfaces
Print whole slide here
3. Red Algae (Rhodophytes):
found in warm seawater.
Red because its pigments absorb green, violet and blue light which penetrate the furthest in water, allowing red algae to live at great depths.
SUSHI! & Agar for bacterial growth 20

21. Rhodophytes (red algae)

22. Unicellular, Plant-Like Protists
4. Diatoms (Chrysophytes)
most abundant algae in the oceans
rigid cell walls contain silica (sand & glass)
big component of plankton
major source of atmospheric oxygen
Main producers of aquatic food webs
5. Dinoflagellates (Pyrophytes)
Photosynthetic; mostly marine
stiff cellulose protective coats
Have two distinct flagellae in life cycle
Numerous; important base for marine food chains
Contain toxins (build up in shellfish that eat them).
Phosphorescent (photosynthetic pigment):form “red tides”
Print whole slide here
More on euglena:
euglenoid flagellae
Can also absorb materials; can survive in area with decaying materials
Both animal like and plant like then: can move and can photosynthesize
6. Euglenoids (Euglenophytes)
Freshwater; have chloroplasts
One large anterior whip-like flagella (updated)
Eat smaller organisms if no sun; Eyespot to find sunlight
Reproduce via mitosis 22

23. Fungi-Like Protists
Slime and Water Moulds
Have the characteristics of fungi, protozoa and plants.
Glide from place to place and ingest food like protozoa.
Cellulose in their cell walls like plants.
Also absorb nutrients from their environment like fungi (nutrients from the dead) 23

24. 1. Water Moulds (Phylum Oomycota)
Fungi-Like Protists
1. Water Moulds (Phylum Oomycota)
Ex. Water moulds, white rusts and downy mildews.
Filamentous, resemble fungi
Most live as saprotrophs on dead organic materials, but some are parasitic on plants, insects and fish.
Extend fungus like threads into their host where they release digestive enzymes and absorb the nutrients.
The cause of the Irish Potato Famine. 24

25. 2. Plasmodial Slime Moulds (Phylum Myxomycota)
Fungi-Like Protists
2. Plasmodial Slime Moulds (Phylum Myxomycota)
visible to the naked eye as tiny slug like organisms that creep over damp, decaying plant material in forests and fields.
This blob, called a plasmodium, contains many nuclei.
Feed in a similar manner to amoebae.
Spores form in improper living conditions.
Dog vomit slime mould  25

26. 3. Cellular Slime Moulds (Acrasiomycota)
Fungi-Like Protists
3. Cellular Slime Moulds (Acrasiomycota)
exist as individual amoeboid like cells with one nucleus each.
Feed by ingesting tiny bacteria or yeast cells.
When food becomes scarce, the cells release a chemical that causes them to gather together to form a pseudoplasmodium.
This is a jelly-like mass, which produces a sporangia that releases spores. 26

27. Protists’ modes of reproduction
Asexual
Sexual
Via binary fission
Involves conjugation
Alternation of generation (multicellular protists)
Paramecia
Results: 2 genetically identical paramecia daughter cells
Results of conjugation: Two cells exchanged their genetic materials

28. Multicellular Protists’ Reproduction
Sexual reproduction involves formation of gametes
Gametes are haploid (half the usual # of chromosomes)
When a sperm meets an egg, a zygote is formed having full set of chromosomes
Zygotes are thus diploid (full set of chromosomes)
Multicellular protists can alternate between a diploid and a haploid stage called Alternation of generations
Both diploid and haploid stages are required for the life cycle to be completed in such protists
Watch Alternation of generations Green algae:
In plants & some protists
Multicellular haploid & multicellular diploid
phases alternate in sexual life cycles
Life cycles that involve:
– multicellular haploid stage (gametophyte) that
produces gametes
– and alternates with
– multicellular diploid stage (sporophyte) that
produces sporeson%20of%20Generation/28_A01s.swf

29. Brown algae’s alternation of generation life cycles
(is Haploid,
multicellular)
(Diploid)
Watch Alternation of generations Green algae:

30. Summarize Brown algae’s alternation of generation
Large brown algae is a diploid sporophyte
Sporophyte produces single-celled, haploid spores
Spores then grow into multicellular, haploid gametophytes
Gametophytes will produce haploid sperms and eggs
When a sperm is fused with an egg, a diploid zygote is formed which later grow into a multicellular sporophyte (i.e. the large brown algae).

31. Recap and review (HW if not done in class):
Watch:
Q1: How is protista different from kingdom archaea and bacteria? A:
Q2: How is protista different from kingdom fungi?
Q3: How is protista different from kingdom plantae?
Q4: How is protista different from kingdom animalia?

32. Recap and review (Cont.)
Watch:
Q5: Three modes of nutrition of protists? A:
Q6: Your friend one day claims that malaria can be effectively treated with antibiotics. Do you think so too? Why or why not?
Q7: Use today’s lesson note to summarize the importance of protists (i.e. their benefits and harms to us)

33. Recap and review (Cont.)
Q8: What are some implications of climate change, particularly ocean acidification and change in global temperature, on the livelihood of the marine protists and the spread of malaria?
Q9: Research the following about African sleeping sickness:
What causes it?
How is it spread?
What are the symptoms?
How can it be treated?

34. Trypanosoma brucei & African sleeping sickness
Belong to Phylum: Euglenoids
General symptoms include:
Drowsiness during the day, Fever, Headache, Insomnia, uncontrollable Sleepiness, Sweating
Sleeping sickness
this page to a friendShare on facebookShare on twitterBookmark & SharePrinter-friendly version
Sleeping sickness is infection with germs carried by certain flies. It results in swelling of the brain.
Causes
Sleeping sickness is caused by two germs (protozoa), Trypanosoma brucei rhodesiense and Trypanosomoa brucei gambiense. The more severe form of the illness is caused by T. b. rhodesiense.
Tsetse flies carry the infection. When an infected fly bites you, the infection spreads through your blood.
Risk factors include living in parts of Africa where the disease is found and being bitten by tsetse flies. The disease does not occur in the United States. But travelers who have visited or lived in Africa can have the infection.
General symptoms include:
Anxiety
Drowsiness during the day
Fever
Headache
Insomnia at night
Mood changes
Sleepiness (may be uncontrollable)
Sweating
Swollen lymph nodes all over the body
Swollen, red, painful nodule at site of fly bite
Weakness
Without treatment, death can occur within 6 months from cardiac failure or from T. b. rhodesiense infection itself. T. b. gambiense infection causes the classic sleeping sickness disease and gets worse more quickly, often over a few weeks. Either disease needs to be treated immediately.
Complications include:
Injury related to falling asleep while driving or during other activities
Gradual damage to the nervous system
Uncontrollable sleep as the disease gets worse
Coma
Without treatment, death can occur within 6 months from cardiac failure 
Complications include:
Injury related to falling asleep while driving or during other activities
Gradual damage to the nervous system
Uncontrollable sleep as the disease gets worse
Coma

35. Irish Potato Famine (1845- 1852)
Caused by Phytophthora infestans
- A fungi-like protist (Oomycota); not a viroids
The genetically identical lumpers were all susceptible to a rot caused by Phytophthora infestans, which turns non-resistant potatoes to inedible slime. Students have asked if it was Viroids that caused Irish Potato Famine in 1840s

36. Beaver fever Caused by Giadia lambia or G. intestinalis
Class: Zoomastigophora
 single-celled protozoa (i.e. animal-like protist)

37. Watch Alternation of generations Green algae: http://kisdwebs. katyisd