The Kingdom Protista

Chapter 20

What is a Protist?

Any organism that is not a plant, an animal, a fungus, or prokaryote.

Are eukaryotes that are not members of the kingdoms, Plantae, Animalia, or Fungi

Classification of Protists

Protists are so diverse that many biologists suggest that they should be broken up into several kingdoms.

Unfortunately, biologist do not agree on how to classify the protists.

Classification of ProtistsSection 20-1

are classified by

which includewhichwhich which

Protists

Animallike FunguslikePlantlike

ParasitesTake in food from the environment

Produce food by photosynthesis

Obtain food by external digestion

Decomposers

Animallike Protists: Protozoans 4 phyla of the animallike protists -

Distinguished from one another by their means of movementZooflagellates-move by flagella ex.

Trychonympha(termite), Trypanosoma(Tse Tse Fly)

Sarcodines-move by pseudopods ex. amoebaCiliates-move by cilia ex. parameciumSporozoans-no movement, parasites ex.

plasmodium

Zooflagellates

Animallike protists that swim using a flagella

Most have 1-2 flagella Live in lakes & streams,

where they absorb nutrients from decaying matter

Some live within bodies of other organisms, taking advantage of the food from larger organisms

Can reproduce by asexual and sexual reproduction

Sarcodines

Move via temporary cytoplasmic projections known as pseudopods

Amoebas Surround food and

form a food vacuole

Amoeba

Food vacuole

Nucleus

Contractile vacuole

Pseudopods

Ciliates

Contain short hairlike projections called cilia

Use cilia for feeding & movement

Found in both fresh & salt water

Ciliates

Anal pore

GulletOral groove

TrichocystsLysosomes

Food vacuoles

Contractile vacuole

Micronucleus

MacronucleusCilia

Sporozoans

Do not move on their own & are parasitic

Animallike Protists & Disease

Malaria African sleeping sickness Amebic dysentery

Malaria

One of the world’s most serious infectious disease

2 million people still die from malaria every year Carried by the female Anopheles mosquito

Cycle of Malaria (pg. 503)

Symptoms & Treatment of Malaria

Severe chills Fever

There are a number of vaccines against malaria but to date most are only partially effective

Controlling mosquitoes is the best method to controlling malaria

African Sleeping Sickness

Zooflagellates of the genus Trypanosoma Spread by the bite of an insect known as the

tsetse fly

Symptoms

Begin to show 1 to 4 weeks after bite Chills Rashes Infect nerve cells: severe damage causes

some individuals to lose consciousness, lapsing into a deep and sometimes fatal sleep

Treatment

Hospitalization Medications Follow-ups for 2 years

Amebic Dysentery

Common in areas with poor sanitation Severe diarrhea Caused by an organism that looks like the

harmless amoebas Entamoeba, a parasite spread by contaminated

drinking water Attacks the wall of the intestine, causing

extensive bleeding

Amebic Dysentery

Can also occur in the crystal-clear mountain streams

Caused by another flagellated pathogen, Giardia Giardia produces tough, microscopic-size cysts

that can be killed only be boiling water thoroughly or by adding iodine to the water

Causes severe diarrhea and digestive system problems.

Ecology of Animallike Protists

Essential roles in the living worldLive symbiotically with other organismsRecycle nutrients by breaking down dead

organic matterLive in seas and lakes & are a part of the food

chain

Trichonympha

Zooflagellate that lives within the digestive systems of termites

Makes it possible for termites to eat wood Termites do not have an enzyme to

breakdown wood The Trichonympha does it for them

Homework

Guided Reading Worksheets20-120-2

Due Wednesday, February 16th

Plant-Like Protists Commonly called Algae

Contain chlorophyll and carries out photosynthesis

Unicellular Algae-classified by pigments Phylum Euglenophyta

2 flagella but no cell wall Phylum Chrysophyta

Gold-colored chloroplast Phylum Bacillariophyta

Called diatoms Cell walls contain silicon

Phylum Pyrrophyta Called dinoflagellates

Draw a Euglena

see p. 507, Figure 20-10)

Ecology of Unicellular Algae

Make up most of phytoplanktonSmall photosynthetic organisms near

surface of ocean½ of all photosynthesis on Earth is

performed by the algaeSource of nourishment for small fish

Algal Blooms and “Red Tides

Help recycle sewage and fertilizer Grow too much, deplete nutrients, die, rid

water of oxygen, choke out fish life Can produce toxins, eaten by clams and

shellfish, eaten by humans and cause death

Multicellular Algae (mostly)

Phylum RhodophytaRed Algae

Phylum PhaeophytaBrown Algae

Phylum ChlorophytaGreen Algae

Draw Brown Algae

see p. 511, Figure 20-15

Reproduction

Alternation of GenerationsLife cycle includes both haploid and diploid

generationEnables them to survive unfavorable

conditions

Analyzing Data

Pg. 508 Questions 1-4

Fungus-Like Protists

Like fungi-absorb nutrients from dead or decaying organic matter

Different from fungi-have centrioles and lack chitin cell walls

Funguslike Phyla

Phylum AcrasiomycotaSlime mold

Phylum Myxomycota Acellular slime mold

Phylum OomycotaWater mold (white mold on dead fish)

The Great Potato Famine

Phytophthora infestans (Phylum Oomycete) destroyed 60% of the potatoes in Ireland in 1845

Between 1845 and 1851 at least one million Irish people died of starvation or disease

One million Irish emigrated to the U.S. and other countries

Homework

Guided Reading Worksheets20-320-420-5Preparing for TAKS pg. 525 1-4

Due Friday, February 18th