Kingdom Protista “the very first”

any organism that is not a plant, animal, fungus, or prokaryote (bacteria)

Eukaryotes 1.5 billion years ago Classified by nutrition mode Animal like, Plant like, or Fungus like

Symbiosis Relationship between organisms; one organism

lives in or on the other Organisms involved in relationship are called

symbionts 3 Types:

Mutualism: both symbionts benefit Commensalism: one symbiont benefits; other is

unaffected Parasitism: one symbiont benefits; other is harmed

Vectors Mechanically transfer parasite into host Exs: tse-tse fly; female Anopheles

mosquito Carriers

Unaffected by disease

A) Animal-like Protists: Protozoans

Protozoa-”First animals”

Heterotrophs Four phyla based

on how they move Unicellular

1) Phylum Zoomastigina: Zooflagellates flagella Absorb food through

their cell membranes Most reproduce

asexually- binary fission

Live in lakes and streams or bodies of other organisms

Diseases (African Sleeping Sickness)

Trypanosomiasis Trypanosoma – Tsetse Fly Chills, rashes, nerve cell damage, coma

Termites and Trichonympha Symbiotic (lives off food from termite) Lives in termite gut Contains cellulase that digests wood

2) Phylum Sarcodina: Sarcodines Pseudopods “false foot” – cytoplasmic projections for

eating and movement Best known sarcodine - Amoeba Amoeboid movement Contractile and Food Vacuoles Binary Fission Foraminiferans – secrete calcium carbonate shells (chalk),

accumulates on bottom of ocean.

Contractile Vacuole (pump water)

Nucleus

Food Vacuole (store food)

Pseudopods

ex. AMOEBA

Amebic Dysentery (Amebiasis)

• Entamoeba-parasite spread by contaminated drinking water from poor sanitation

• Severe diarrhea, attacks intestines, bleeding

• Boiling water or iodine kills parasite

3) Phylum Ciliophora: Ciliates Cilia – used for feeding and movement

Short, hair-like projections Binary Fission and Conjugation (stress) Best known ciliate – paramecium Freshwater and saltwater Trichocysts-stiff projections for defense of

paramecium

Internal Anatomy Two nuclei Macronucleus

respiration, protein synthesis, and digestion. Micronucleus

conjugation and contains a reserve copy of genes.

Anal pore

GulletOral groove

TrichocystsLysosomes

Food vacuoles

Contractile vacuole

Micronucleus(conjugation) Macronucleus

Cilia

Figure 20-5 : ex. Paramecium

Nutrition The cilia move food into the oral groove which

leads to the gullet. The food is forced into food vacuoles Lysosomes break down the food with enzymes Undigested food is removed through the anal

pore Contractile Vacuoles pump water in and out to

maintain homeostasis

Macronucleus

Micronucleus

Conjugation

MEIOSIS Exchange ofmicronuclei

Macronucleidisintegrate

New macronuclei

form

Genetically identical

paramecium form

*note: conjugation is a sexual process but NOT a form of sexual reproduction b/c no new individuals are formed. However, new combinations of genetic information are produced.

4) Phylum Sporozoa: Sporozoans Parasitic protists

Parasites of many different organisms, including worms, fish, birds, and humans.

Many protists cause serious disease Cannot move independently Reproduce using sporozoites A sporozoite can attach itself to a host and

lives as a parasite.

Diseases Malaria- sporozoan Plasmodium Saliva of the female Anopheles mosquito Sporozoites enter the bloodstream and the

parasite infects the liver cells and red blood cells. Red cells burst and release toxins into the

bloodstream 2 million people die each year from malaria

800 million infected worldwide

B) Plant-like Protists: Unicellular Algae

Base of the food chain “phytoplankton” photosynthetic pigments Autotrophs 4 phyla based on the type of pigments they

contain

1) Phylum Euglenophyta: Euglenophytes

two flagella Lack a cell wall Cell membrane called a pellicle Chloroplasts – photosynthetic Heterotrophic if no sunlight available Eyespot – finds sunlight Pellicle – tough and flexible

Gullet

Chloroplast

NucleusEyespotFlagella

Euglena Fig. 20-10Carbohydrate storage bodies

Pellicle

Contractile vacuole

2) Phylum Pyrrophyta “fire plants”: Dinoflagellates 50% photosynthetic 50% heterotrophs 2 flagella Plates made of

cellulose for protection

Many are bioluminescent

Algal Blooms• Protists grow rapidly in areas rich in

sewage• Excessive waste leads to excessive

growth protists and algae• Deplete nutrients from water• Dead algae rob water of its oxygen

• Dead marine life

Red Tide Water appears red due

to “Algal Bloom” Certain species of

dinos produce toxin that is taken in by shellfish

Ban on shellfish Can cause PSP

Red Tide off the coast of CA

Paralytic Shellfish Poisoning PSP is caused by a dino species that

produces a toxin that is taken up by mollusks.

Eating these infected shellfish can cause serious illness, paralysis, or death

3) Phylum Chrysophyta: Chrysophytes Yellow-green and golden-brown algae Gold-colored chloroplasts Pectin cell wall Store food in the form of oil

4) Phylum Bacillariophyta: Diatoms

Cell walls – silicon (glass)

Cannot decompose

C) Plantlike Protists: Multicellular Algae = Seaweed

Red, Brown, and Green

1) Phylum Rhodophyta: Red Algae

Contain Chlorophyll a and Phycobilins Absorb blue light – 260 meters, very deep Important role in forming coral reefs Chondrus crispus- Irish moss

Chondrus crispus – Irish Moss

2) Phylum Phaeophyta: Brown Algae

Chlorophyll a and c, Fucoxanthin Holdfast, Stipe, Blades, Bladders

(Fig 20-15) Fucus- Rockweed Sargassum Kelp

Kelp

Rockweed

Fucus : Rockweed

Sargassum

Blade

Stipe

Hold Fast

3) Phylum Chlorophyta: Green Algae

Cellulose in their cell walls Chlorophyll a & b Stores food as starch Very similar to plants

Unicellular Green Algae Chlamydomonas Lives in ponds, wet

soil, etc.

Colonial Green Algae Spirogyra Volvox – connected strands of cytoplasm,

coordinated flagella movement

Multicellular Green Algae

Sea lettuce- Ulva

Importance of Algae

•Base of the food chain

•Kelp forests – habitats

•50% of oxygen production

•Used in many foods and products