PROTISTA NOTES
Characteristics:
1.
2.
3.
Eukaryotic
Mostly unicellular
Photosynthetic and ingestive
Protozoa—animal like protists
1.
Sarcodina—protozoans with false feet, or pseudopodia. This
type of movement is known as ameboid movement and is
accomplished by cytoplasmic streaming. The fresh water
Amoeba is the genus most frequently studied as an example of
this group. Ingest food by phagocytosis. Reproduction by binary
fission.
Two marine sarcodines include:
A. Foraminifera—have calcium carbonate shells
B. Radiolaria—silica (silicon dioxide) inside their shells
2.
Zoomastigina—protozoa that have at least one flagellum for
movement.
Parasitic forms cause the following diseases:
A. Trypanosoma—causes African sleeping
sickness. Transmitted by the tsetse fly.
B. Leishmania—carried by sand flies, causes
leishmaniasis which is characterized by
disfiguring skin sores and may be fatal.
C. Giardia—carried by muskrats and beavers.
Characterized by fatigue, diarrhea, cramps,
and weight loss. May be fatal.
3.
Sporozoa—spore-bearing protozoa. All sporozoans are parasitic
and non-motile. This type of protozoan is responsible for
malaria, and is transmitted by mosquitoes.
4.
Ciliophora—protozoa that move using cilia. The most
commonly studied example off this genus is called Paramecium.
Ingest food through oral groove covered by cilia. Enters food
vacuole through mouth pore. Reproduction is by binary fission or
conjugation.
The protozoa make up marine zooplankton which are an important
part of the ocean’s food chain.
Algae—plant like protists
1.
Green algae (chlorophyta)—includes unicellular, colonial,
filamentous, and thalloid (leaf-like) forms.
Examples include:
A.
B.
C.
D.
2.
Spirogyra—spiral chloroplasts, filamentous
Chlamydomonas—cup-shaped chloroplast, unicellular
Volvox—spherical colonies
Ulva—thalloid
Euglenoids (euglenophyta)—forms of algae that possess flagella
and also contain chloroplasts. Euglena is the best known genus in
this group. Nutrition by photosynthesis unless placed in the dark,
then they become heterotrophic.
3.
Flame-colored algae (pyrrophyta)—contain a flame colored
pigment in addition to chlorophyll. Most of these are known as
dinoflagellates. Each is a one-celled organism which bears two
flagella. These are the cause of the red tide which occasionally
appears in the Gulf of Mexico. These high concentrations of
dinoflagellates, or blooms, may cause fish kills. Certain types of
these algae may also exhibit bioluminescense.
4.
Golden-yellow algae (chrysophyta)—contain a yellow green
pigment in addition to chlorophyll. Most important members of the
group are called diatoms. These are distinguished by their
“glass” walls, formed primarily of silica.
5.
Brown algae (phaeophyta)—all multicellular and usually large.
Individuals may be more than 100 m long. Thallus consists of a
holdfast (anchors to a rock), a stipe (stemlike structure), and
blade (leaflike structure where photosynthesis occurs). Cell walls
contain alginic acid, a source of commercially important alginates.
Alginates are polysaccharides used to make gels for ice cream
and other foods.
Examples:
A. Fucus—rockweed
B. Kelp—grown commercially in Japan
6.
Red algae (rhodophyta)—mostly marine and multicellular. Usually
less that I m long. Commonly grow at depths of 150 m and have
been discovered at depths of 268 m. Cell walls coated with a
sticky substance called carageenan, a polysaccharide, which is
used to produce cosmetics, gelatin capsules, and some cheeses.
The unicellular algae make up marine phytoplankton which are also
an important part of the ocean’s food chain.
Fungus-like Protists—lack chloroplasts and absorb nutrients from
dead organic matter. Lack the chitin in the cell walls of true fungi.
1.
Slime molds—at some stages in their life cycle they look like
amoebas and at other stages form mold-like clumps that produce
spores.
Two types:
2.
a.
Cellular—spend most of their life as ameboid, free-living
cells.
b.
Acellular—begin their lives as amoeba-like cells, when they
aggregate the cells fuse to produce structures with many
nuclei
Water molds—thrive on dead and decaying organic matter in
water and are plant parasites on land
Economic importance of Kingdom Protista:
1.
Important part of aquatic food chains.
2.
Diatomaceous earth has numbers of uses. A few are listed
below:
a. Car and silver polishing powders
b. Bleaching powders
c. Insulating materials for hot or cold pipes
d. Filters for aquaria
e. Fillers for paints
f. Explosives (dynamite)
3.
It is generally believed that an unknown but significant
percentage of the world’s oil supply is off diatom origin.
4.
Fish kills due to red tides.
5.
Clogging screens and sand filters in water systems.
6.
Fouled drinking water.
7.
Ruined recreational sites due to dense algal growths.
8.
Diseases caused by protozoa include:
a. Amoebic dysentery caused by a type of amoeba.
b. African sleeping sickness caused by Trypanosoma
gambiense, is spread by the tsetse fly.
c. Dumdum fever, or kala-azar, caused by Leishmania
donovani, causes enlargement of the liver and the
spleen as well as numerous sores on the skin. Occurs in
India, northern Africa, and parts off South America
d. Malaria, caused by a species of Plasmodium, is spread
by mosquitoes. Ranks as one of the most serious
infectious diseases on the globe.
9.
Certain types of seaweed may be used for food. By-products of
seaweed may be used for cosmetics, in the production of drugs
and vitamins, and in the production of some foods.
KINGDOM FUNGI
Characteristics:
1.
2.
3.
4.
5.
6.
7.
8.
Eukaryotic
Unicellular and multicellular forms
Absorptive nutrition
Fungi that feed on dead things are called saprophytes
Mycelium—body of the fungus
Hyphae—threadlike structures that make up the body of the
fungus
Reproduction—both sexual and asexual
Cell walls contain chitin
Phyla of Kingdom Fungi:
Sporangium fungi (zygomycota)—typical members of this
class have a vegetative (mycelium) body composed of
filaments (hyphae) that run through and on the substance
upon which they are growing. The mycelium bears
sporangia, which produce spores for the reproductive
process. They grow in warm, moist places including soil,
manure, fruit, and starchy food. Examples of these types of
fungi are:
1.
2.
Bread mold (Rhizopus)
White rusts
Sexual reproduction by production of zygospores. (Figure
20.7. page 552)
Sac fungi (ascomycota)—characterized by the formation of
saclike structures called asci, which usually contain four to
eight spores. The fungi in this class cause many important
plant diseases. Examples are the chestnut blight, which has
almost wiped out the chestnut trees in North America, and
the Dutch elm disease, which has been so destructive to our
shade trees. It also includes the powdery mildews, which are
destructive to many species of higher plants. Types of sac
fungi include:
1.
Cup fungi—grow on dead and decaying matter.
Appear as cup shaped bodies with spore bearing
organs within the cups.
2.
Morel fungi—edible and highly prized for their
flavor.
3.
Truffles—edible, highly prized by gourmets.
4.
Blue-green molds—may be red, yellow, and black.
Grow on nearly all kinds of organic matter when
moisture and warmth are sufficient.
5.
Ergot—parasite of wheat, rye, and wild grasses.
Poisonous when ingested by man in sufficient
quantities. There have been many cases of ergot
poisoning from eating bread made with ergot
infected wheat or rye.
6.
Yeasts—one-celled organisms, have no fruiting
bodies. Used in bread to make it rise and in the
manufacture of wine and beer to cause
fermentation.
Club fungi—basidiospores borne on small clubs, or
basidia. Examples include:
1.
Gill fungi—include many species commonly known
as mushrooms or toadstools.
2.
Shelf or bracket fungi—grow from the trunk and
limbs of living and dead trees.
3.
Puffballs—bear spores within a ball.
4.
Stinkhorn fungus—produces a disagreeable odor.
5.
Rusts—rust colored mass of spores. Wheat rust
is one of the most important economically.
6.
Smuts—similar to rusts, but are black masses
covered by a membrane. Corn smut is probably
the best known of this group. It grows as a large
black mass on ears of
corn.
Imperfect fungi (duteromycota)—have never observed
sexual reproduction in these fungi.
1.
Ringworm and athletes foot fungi
2.
Penicillium—used to produce the antibiotic
penicillin
3.
Blue-green fungus—used to produce bleu cheese
4.
Aspergillus—causes disease called aspergillosis (there
is some inconsistency with the classification of this
fungus)