Download 6 Divisions of Algae

Protists
Learning Target Objectives (I can …):
•Distinguish between types of protists based on their
characteristics and types of movement.
•Label and describe protist anatomy (structure) and
physiology (function).
•Identify parasitic protists, the diseases they cause, and the
vectors involved in their spread.
•Compare/contrast the types of protists and list examples of
each.
Vocabulary:
Protozoa * Algae * Slime molds * endosymbiosis *
eukaryote * pseudopodia * phagocytosis * exocytosis *
contractile vacuoles * binary fission * cysts * amoeba *
cilia * pellicle * trichocysts * macronucleus *
micronucleus * oral groove * mouth pore * gullet * anal
pore * conjugation * nonmotile * vector * algae *
pyrenoids * thallus * phytoplankton * zooplankton *
diatoms * bioluminescent * red tide * euglena * eye spot
* fruiting bodies
Kingdom Protista: 3 Major Divisions (Subkingdoms)
I. Protozoa – heterotrophic, may be parasitic, “animal-like”.
Eat bacteria, algae, and other protists.
II. Algae – autotrophic (photosynthesize), “plant-like”,
includes seaweed.
III. Slime Molds – heterotrophic, decomposers (detritivores),
some are parasitic.
All protists are eukayotic.
Endosymbiosis – theory that eukaryotes evolved from
prokaryotic parasites living inside other prokaryotes. The
parasites eventually became organelles.
mitochondria = parasitic bacteria
chloroplasts = parasitic blue-green bacteria
I. Protozoans are divided into 4 phyla based on how they
move.
1) Phylum Sarcodina – move by projecting cytoplasm
outward. These projections are called pseudopodia (false feet).
The pseudopodia are also used to surround food, creating a
vacuole. This is a form of phagocytosis.
Wastes leave the cell in reverse. A vacuole opens to the outside,
releasing wastes. This is called exocytosis.
Contractile vacuoles are used to pump out excess water for
freshwater sarcodines.
Reproduction is by binary fission (like mitosis)
Cysts are formed by sarcodines for protection in unfavorable conditions.
Ex: Amoeba
2) Phylum Ciliophora – move by cilia (short, hair-like projections that
wave like tiny oars). These may cause twisting motion too.
Pellicle – rigid outer membrane
Trichocysts – capsules containing barbed structures that can be
projected from just below the surface for defense.
Macronucleus – controls cell respiration, protein synthesis, digestion,
and asexual reproduction.
Micronucleus – controls sexual reproduction (genetic variability)
Ex: Genus Paramecium has an oral groove with cilia sweeping food into
this mouth-like structure and into the mouth pore (an opening). From
here, food is put into vacuoles at the gullet and then the vacuoles float
around in the cytoplasm delivering nutrients.
Undigested food leaves the paramecium as vacuoles reach the anal
pore.
Reproduction is usually asexual (binary fission) but may be (similar to)
sexual reproduction. Sexual reproduction involves sharing genetic
material with another paramecium. Eventually each paramecium splits in
two. This process is known as conjugation. No eggs or sperm are
produced (no meiosis). Therefore it is NOT true sexual reproduction.
Other ciliophora – paramecium, vorticella, Didinium (barrel-shaped) and
Balantidium.
3) Phylum Zoomastigina or Mastigophora
Move by long, whip-like flagella (may have more than
one) that push or pull them through water. (Many parasites
in this group.)
Flagellates include: Trypanosomes (African Sleeping
sickness) Leishmania, Giardia, Trichomonas (STD)
4) Phylum Sporozoa
- nonmotile (can’t move on their own), ALL are PARASITIC,
spore forming, require 2 hosts to complete their life cycle.
Spore form during asexual reproduction.
Sporozoa include: Toxoplasma, Plasmodium (malaria)
Diseases Caused by Protozoans
Entamoeba histolytica – (amoebic dysentery)
Bloody diarrhea & even death
May penetrate the intestinal lining
Many amoeba live in our mouths and intestines
Balantidium coli – (ciliate)
Infects pigs, monkeys/apes, man
Bloody diarrhea
Worst if person has low stomach acid
Trypanasoma gambiense & T. rhodesiense – (flagellates)
Cause African sleeping sickness
Infect the brain
Transmitted by tsetse fly
Trypanosoma Cruzi - (flagellate)
- Causes Chagas disease (South America)
- Damage to the heart causes death
- Transmitted by the Reduviid bug (kissing bug) which usually bites near
the eyes.
Giardia lamblia – (flagellate)
- Infects intestines, can cause “greasy” diarrhea, and/or malnutrition.
- “Don’t drink the water” – cysts are spread through water; chlorine
doesn’t kill it but boiling water will.
- Found even in Wisconsin streams, lakes, etc.
Trichomonas vaginalis – (flagellate)
- infects genitalia/reproductive tract
- Usually no symptoms but can cause abdominal pain, increased
bleeding, etc.
- Spread by sexual contact OR moist surfaces
Toxoplasma gondii – (sporozoa)
- causes stillbirths, mentally retarded babies, or visual problems in
babies born to infected mothers
- Infection usually occurs from ingesting or inhaling an oocyst
- spread through cat feces. Pregnant women should stay away from
litter boxes.
Plasmodium sp. – (sporozoa)
- causes malaria
- chills, high fevers, liver & kidney damage & possible death
- infection occurs in Red Blood Cells (RBCs)
- Every 2-3 days, spores burst the RBCs, releasing toxins, creating the
above symptoms, & causing anemia
- Fevers are so high that they were used to kill syphillis & possibly Lyme
disease organisms BUT malaria itself is becoming resistant to treatment.
- Spread by Anopheles mosquito
Vector – an organism that spreads or “carries” a parasite from 1 host to
another
II. Algae (plant-like protists)
- autotrophs with chloroplasts
Pyrenoids – organelles that synthesize (make) & store starch
- require moisture to reproduce
- many have flagella
Thallus – body of alga
Phytoplankton – aquatic, unicellular algae eaten by fish. etc., produce
oxygen
(zooplankton – protozoans living in aquatic areas, eaten by fish, etc.)
6 Divisions of Algae
1) Chlorophyta – green algae
- chlorophyll a & b
- store food as starch
- cellulose cell walls
These 3 characteristics are the same for plants. These are most likely
the ancestors of plants. Includes: spirogyra, chlamydomonas (STD),
Volvox
2) Phaeophyta – brown algae
- fucoxanthin pigment
- large and multicellular
- produce substance used in food gels
- usually anchored to seafloor
3) Rhodophyta – red algae
- contain phycobillins & chlorophyll a & d
- some make up part of coral reefs with their cell walls
- some make “carageenan” used in cosmetics, gelatin capsules, some
cheeses, ice cream, and agar
4) Chrysophyta – golden brown algae
- diatoms
- shells with silica do NOT decompose
- they’re used in swimming pool filtration, detergents, paint removers,
insulators, etc
- produce bulk of world’s oxygen
5) Pyrrophyta – “fire algae” or dinoflagellates
- many are bioluminescent (make their own light)
- red tide – USUALLY due to large “blooms” of dinoflagellates. Toxins
produced can cause respiratory paralysis if infected fish, mussels, etc.
are eaten.
6) Euglenophyta – Euglena
- partly autotrophic & partly heterotrophic (when in the dark)
- contain chlorophyll a & b
- sometimes considered protozoans
- flagella used for movement
- eyespot detects light
- contractile vacuole pumps out freshwater
Slime Molds
Have 2 stages:
a) reproductive stage – resemble fungi in this stage
(similar reproductive structures)
b) feeding stage – here they look & act like amoebas.
Feed on decaying material.
2 Types of Slime Molds:
1) Plasmodial Slime Molds
- have many nuclei scattered throughout cytoplasm
- fruiting bodies release spores (to reproduce). These look
like amoebas. When 2 unite, a new plasmodium develops.
2) Cellular Slime Molds
- 1 nucleus per cell
- group together when food is scarce but keep individuality