Why do most kitchens have a junk drawer?

• Junk drawers hold miscellaneous items that don’t quite belong anywhere else.

Scientists discovered a group of species that didn’t quite belong to

the kingdoms of life…

Species that are eukaryotic, but not plant, animal, or fungus?

Kingdom Protista

Protists

• Kingdom Protista is the “junk drawer” kingdom…– Eukaryotic species are

classified as protists when they don’t belong anywhere else.

Protists are a very diverse group of organisms containing over

200,000 species.

What are protists?

• All protists are eukaryotes:– Have a nucleus– Contain membrane-bound

organelles

Any eukaryote that doesn’t fit as a plant, animal, or fungus is characterized as a protist.

Protist Classification

• Protists can be classified into 3 categories:

Heterotrophs: Animal-Like Protists

Autotrophs: Plant-Like Protists

Decomposers & Parasites:

Fungus-Like Protists

Animal-Like Protists - Protozoa

• Means “first animals”• All unicellular• Classified by movement-type

Giardia lamblia

Protozoa

1. Zooflagellates – use flagella to move• A tail that whips back & forth

Protozoa

2. Sarcodines – use pseudopods to move• Pseudopods are an extension of cytoplasm

Protozoa

3. Ciliates – use cilia to move• Like small hairs

Protozoa

4. Sporozoans – do not move on their own• Parasitic to animals

Malaria is caused by the sporozoan Plasmodium.

Plant-Like Protists - Algae

• Protists that contain chlorophyll & other pigments for photosynthesis

• Can be multicellular or unicellular

Multicellular Algae

• Include seaweeds & kelp• 3 types of multicellular algae:

– Red Algae– Brown Algae– Green Algae

Red Algae

• Contain green & red pigments • Role/Function:

– Deeper sea, great at harvesting light– Help form coral reefs– Some used in foods & to make agar

Brown Algae

• Contain green & brown pigments • Role/Function:

– Form large habitats in aquatic ecosystems– Used in some food

Green Algae

• Green pigments• Role/Function:

– Some form symbiotic relationships with other organisms (lichens).

Spirogyra

Unicellular Plant-Like Protists

• Euglenophytes• Chrysophytes• Diatoms• Dinoflagellates

Euglenophytes• 2 Flagella• No cell wall• Contain chloroplasts

Eyespot!

What do you think it is used for?

Eyespot in Euglenophytes• The eyespot is used to locate the light needed for

photosynthesis.

Eyespot!

It’s not actually used for “seeing”, but instead

contains pigments that are sensitive to the light.

Unicellular Plant-Like Protists• Chrysophytes: golden algae

• Diatoms: most abundant, cell walls made of silica

Dinoflagellates

• Half of their life is photosynthetic, other half is heterotrophic

• Cause the Red Tide

Red Tide is an algal bloom that causes marine life to die due to toxins & lack of

oxygen in the water.

Speed Round!On notebook paper (share!)

1. What type of protist causes malaria?

2. What type of protist is kelp?

3. What type of protists have eyespots?

4. How does this protist move?

5. What protists cause red tide?