1. Chapter 20 Protists
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2. 20-1 The Kingdom of Protista
Kingdom of Protista is a diverse group that may include more than 200,000 species
Is an organism that is not a plant, animal or fungus
Multicellular protists are grouped with unicellular protists because multicellular protists are very similar to unicellular protists
Were the first eukaryotes on earth and are thought to have evolved from a symbiosis of several cells according to Lynn Margulis

3. 20-1 The Kingdom of Protista
Classification of Protists:
Are very diverse organisms
Some biologists argue that they should be broken up into several kingdoms
Currently we classify them based on the way they obtain nutrition:
Heterotrophs= called animal like protists
Autotrophs using Photosynthesis= called plant like protists
External digestion= fungus like protists

4. 20-2 Animal Like Protosits: Protozoans
Animal like protists are sometimes called
Protozoans
Are heterotrophs
Are distinguished from one another by the way they move
There are 4 Phylums
Zooflagellates: Protists that swim using flagella
Live in lakes and streams
Absorb food through their cell membrane
Most reproduce asexually through mitosis and cytokenesis

5. 20-2 Animal Like Protosits: Protozoans
2. Sarcodines: Protists that use pseudopods for feeding and movement
Contain ameobas, foraminiferans, and heliozoans
Ameobas use amoeboid movement and food vacuoles to digest food
Foraminiferans are found in warmer ocean regions and secrete shells of calcium carbonate
Heliozonas look like the sun’s rays because of spikes of cytoplasm that project from silica shells

6. 20-2 Animal Like Protosits: Protozoans
3. Ciliates: Use cilia (short hair like structures similar to flagella) for feeding and movement
Are Found in both fresh and salt water
Some of the best know are in the genus Paramecium
Paramecium use Trochocysts (small bottle shaped structures) for defense if confronted by danger
Paramecium have 2 types of nucleui:
Macronucleus= “working library” of genetic information
Micronucleus= “reserve copy” of genetic information

7. 20-2 Animal Like Protosits: Protozoans
Ciliates continued…..
Gullet: an indentation used by cilia to collect food
Contractile vacuoles: cavities in cilia's’ cytoplasm used to collect water
Contracts to remove water to help cells maintain homeostasis
Cilia reproduce asexually by mitosis or cytokinesis or sometimes by conjugation

8. 20-2 Animal Like Protosits: Protozoans
4. Sporozoans: Phylum of protists that do not move on their own and are parasitic
Act as parasites on a large variety of organisms including: birds, worms, fish and humans
Reproduce by means of sporozites
Sporozites can attach to host cell, penetrate it, and then live within it as a parasite

9. 20-2 Animal Like Protosits: Protozoans
Animal Like Protists & Disease:
Animal like protists are some of the most common organisms in the world
Some also cause serious disease
EX: Sporozoan Plasmodium causes the disease known as malaria- spread by female mosquito
EX: Zooflagellates Trypnssoma cause the disease African Sleeping Sickness spread by the tsetse fly
EX: Entamoeba ameobas cause amebic dysentery causing intestinal bleeding

10. 20-2 Animal Like Protosits: Protozoans
Animal like Protists and Ecology
Some animal like protists are beneficial and live symbiotically with other organisms
EX: Trichnomypha is a Zooflagellate that lives within the digestive tract of termites and digests the cellulose in the wood that the termites eat, breaking it down for them.

11. 20-3 Plantlike Protists: Unicellular Algae
Plant like protists are able to carry out photosynthesis
We commonly call plant like protists “algae”
We consider all forms of algae to be protists

12. 20-3 Plantlike Protists: Unicellular Algae
Chlorophyll and accessory pigments allow algae to harvest and use the energy from the sunlight
Different forms of algae have adapted with different forms of chlorophyll: Chlorophyll a, Chlorophyll b, and Chlorophyll c
Each form of chlorophyll allows for algae to capture different wavelengths of the sun’s light
Allows for an increase in the range of depths in which algae can live
Allows for algae to use more than just the sun’s red and violet wavelengths

13. 20-3 Plantlike Protists: Unicellular Algae
There are 4 main groups of unicellular algae:
Euglenophytes
Chrysophytes
Diatoms
Dinoglagellates

14. 20-3 Plantlike Protists: Unicellular Algae
Euglenas are plantlike protists with:
Members of phylum Euglenophyta
Two flagella making them excellent swimmers
No cell wall
Can act as heterotrophs if no sunlight is available
Have an intricate folded cell membrane called a pellicle allowing them to crawl through mud if there is no water to swim

15. 20-3 Plantlike Protists: Unicellular Algae
Chrysophytes are plantlike protsists with:
Members of phylum Chrysophyta
Include the yellow green and brown algae
Have gold colored chloroplasts
Name means “golden plants”
Cell walls sometimes contain pectin
Generally store food in the form of oil instead of starch
Reproduce asexually and sexually

16. 20-3 Plantlike Protists: Unicellular Algae
Diatoms are plantlike protists with:
Belong to the phylum of Bacillariophyta
Produce thin delicate cell walls rich in silicon– the main component of glass
Are among the most abundant and beautiful organisms on earth

17. 20-3 Plantlike Protists: Unicellular Algae
Dinoglagellates are plantlike protists with:
Members of phylum Pyrrophyta
½ are photosynthetic and other ½ are heterotrophs
Generally have 2 flagella
Can reproduce asexually or by binary fission
Like Chrysophyta, members of Pyrrophyta have cell walls that contain cellulose

18. 20-3 Plantlike Protists: Unicellular Algae
Ecology of Unicellular Algae:
Found in both fresh and salt water
Are important organisms that act as the base of the food chain for other aquatic organisms
Make up the majority of photoplankton- photosynthetic organisms found near the surface of the ocean
Can grow in algal blooms– an enormous mass of algae- that deplete the water of nutrients like oxygen that can other organisms like fish

19. 20-4 Plantlike Protists: Red, Brown and Green Algae
Red, Brown and Green Algae have the following characteristics:
Look similar to aquatic plants
Are mostly multicellular
Possess highly specialized tissues
Many have cell walls
The three phylums differ by the photosynthetic pigments they use

20. 20-4 Plantlike Protists: Red, Brown and Green Algae
Red Algae is a plant like protist with:
Members of phylum Rhodophyta
Able to live at great depths
Contain chlorophyll a and accessory pigments called phycobilins
Lack flagella and centrioles
Can be red, green or purple
Are eaten by coral in coral reefs

21. 20-4 Plantlike Protists: Red, Brown and Green Algae
Brown Algae is a plantlike protists with:
Members of the phylum Phaeophyta
Contain Chlorophyll a & c and a brown accessory pigment
Largest & most complex form of algae
Are yellow-brown in color
All are multicellular
Commonly found in cool, shallow coastal water
EX: Giant Kelp

22. 20-4 Plantlike Protists: Red, Brown and Green Algae
Green Algae are plant-like protists with:
Members of the phylum Chlorophyta which means “green plants”
Share many characteristics with plants like cell wall composition, multicellularity, and photosynthetic pigments
Contain chlorophyll a & b
Found in fresh and salt water
There are three types of green algae: unicellular, colonial, or multicellular

23. 20-4 Plantlike Protists: Red, Brown and Green Algae
Reproduction in Green Algae
Life cycle of many algae include both a haploid and diploid generation
Some switch back and forth between haploid and diploid their entire lives
EX: In life cycle of algae Ulva, one of the phases produces male & female gametes known as gametophytes
Some switch back and forth between sexual and asexual reproduction
Ex: Chlamydomanas (single-celled green algae) reproduces asexually by producing zoospores

24. 20-4 Plantlike Protists: Red, Brown and Green Algae
Human Uses of Algae:
Are major food source for ocean life
They produce much of Earth’s oxygen through photosynthesis
Chemicals in algae are used to treat stomach ulcers, high blood pressure, and other health problems
Used in food products such as ice cream,
Used in chemicals such as plastics

25. 20-5 Funguslike Protists Funguslike Protists: Look similar to fungi
Are heterotrophs that absorb nutrients through dead or decaying organic matter
Have centrioles
Lack chitin cell walls that true fungus have
Include the groups: Cellular Slime Molds, Acellular Slime Molds, and Water Molds

26. 20-5 Funguslike Protists Slime Molds are funguslike protists with:
Play roles in recycling organic material
Form mold-like clumps that form spores
There are two major groups:
Cellular Slime Molds
Acellular Slime Molds
Found in damp and rich organic matter such as the forest floor or backyard compost

27. 20-5 Funguslike Protists Water Molds are funguslike Protists with:
Are also called Oomycetes
Are members of the Phylum Oomycota
Thrive on dead or decaying matter in the water & some are plant parasites on land
Produce thin filaments known as hyphae
Display both sexual and asexual reproduction during their lifetime
In oomycetes, sexual reproduction takes place in specialized structures formed by the hyphae called the antheridium and oogonium

28. Kingdom Fungi
Chapter 21

29. Fungi Eukaryotic Heterotrophs
Have cell walls made of chitin (only similarity to plants)
Digest food outside their body & absorb it through cell wall.
Multicellular
Grow on their own food source.

30. Fungi Structure
The body is multicellular & composed of many hyphae tangled together into a thick mass called a mycelium.
Hyphae – filament that can develop cross walls with 2 nuclei.

31. Fungi Reproduction Most reproduce both asexually & sexually.
Asexual-takes place when hyphae break off & begin to grow on their own.
Can produce spores that scatter & grow.
Spores are produced in a sporangia.
Sexual-takes place when hyphae of opposite mating types meet and fuse together.
Fungi are diploid during a small part of their life cycles.

32. Common Molds Ex. Bread Mold
Zygospores-resting spore that contains zygotes formed during sexual phase.
Rhizoids-anchor fungus to the bread.
Stolons-stem-like hyphae that run along the surface of the bread.
Gametangia-produce haploid gamestes when hyphae fuse.

33. Yeast Unicellular fungi
Yeast form asci (ascus-plural) with ascospores which become active in a moist environment.
Budding-process of asexual reproduction.
When baking bread, yeast causes the bread to rise because the fermentation (no oxygen present) of the yeast produces carbon dioxide.

34. Club Fungi Ex. Mushrooms
Basidium-spor-bearing structure that looks like a club.
Gills-hold the basidia on the underside of mushroom caps.
Stalk-stem.

35. Imperfect Fungi
Deuteromycetes-fungi that do not appear to have sexual reproduction.
Penicillum-Penicillium notatum is a mold that grows on fruit & is the source of the antibiotic penicillin.

36. Ecology of Fungi
Since fungi are heterotrophs, the cannot make their own food.
They cannot move or capture food, but their mycelia can grow very rapidly into tissues & cells of plants & other organisms.
Saprobes-obtain food from decaying organic matter.
Parasites-harm other organisms while living directly on or within them.
Symbionts-live in close & mutually beneficial association with other species.

37. Ecology of Fungi
Fungi that are Decomposers play an essential role in balancing ecosystems by breaking down dead organisms.
The breakdown is sped up by fungal production of digestive enzymes.
They return important trace elements & nutrients to the soil.

38. Ecology of Fungi
Fungi that are Parasites feed on living organisms and cause serious disease to plants and animals.
Some cause disease in humans.
The growth of yeasts in moist regions of the body is kept in check by competition from bacteria.
Infections can be treated by antibiotics.
Ex. Wheat rust, athletes foot, yeast infections in female reproductive tracts.

39. Ecology of Fungi Lichens are an example of fungi that are Symbiotic.
They are composed of an alga or a cyanobacterium & a fungus living together.

40. Ecology of Fungi Some fungi are Mutualistic.
Almost half of the tissue of trees is beneath the ground as roots.
These roots are tangled in a partnership with a web of fungal mycelia. This mix is called mycorrhizae.