Kingdom ProtistaKingdom Protista

All protists have a nucleus and are All protists have a nucleus and are thereforetherefore eukaryotic. .

Protists are either plant-like, animal-like or Protists are either plant-like, animal-like or fungus-like.fungus-like.

Plant-like protists are Plant-like protists are autotrophsautotrophs – – they contain chloroplasts and make they contain chloroplasts and make their own food.their own food.

Animal-like and fungus-like protists Animal-like and fungus-like protists and areand are heterotrophsheterotrophs..

The wordThe word protozoaprotozoa means "little means "little animal." They are so named because animal." They are so named because many species behave like tiny many species behave like tiny animals—specifically, they hunt and animals—specifically, they hunt and gather other microbes as food.gather other microbes as food.

The first group is the phylum The first group is the phylum ProtozoaProtozoa. It has been . It has been called phylum Sarcodina. These are called phylum Sarcodina. These are amoebaeamoebae < <ah-me-ah-me-beebee>, which can be subdivided into: >, which can be subdivided into:

1. testate amoebae, which have a shell-1. testate amoebae, which have a shell-

like coveringlike covering

2. naked amoebae, which don't have this 2. naked amoebae, which don't have this

covering.covering. Amoebae ooze along and move by means of Amoebae ooze along and move by means of

pseudopodiapseudopodia (false feet) engulfing food as they go. (false feet) engulfing food as they go.

Phylum Protozoa

Amoebae live in water or moist Amoebae live in water or moist places.places.

They have a cell membrane but They have a cell membrane but nono cell wall. cell wall.

Amoebae also use their pseudopods for feeding by surrounding & engulfing food particles & other protists; called phagocytosis Food is surrounded by a pseudopod & then this part of the cell membrane pinches together forming a food vacuole; called endocytosis Cytoplasmic enzymes enter the food vacuole & digest the food Undigested food & wastes leave by exocytosis

Most amoebae have a contractile vacuole used to pump out excess waterto prevent them from swelling and bursting.

Many members of this phylum havea test made of silica or calciumcarbonate. Tests can build up andform limestone or chalk.

Formation of the White Cliffs of Dover. (United Kingdom)

The second group in Kingdom Protista are the The second group in Kingdom Protista are the ciliatesciliates from the phylum from the phylum CiliophoraCiliophora. These are . These are generally the largest protozoa. generally the largest protozoa.

They are covered with hair-like projections They are covered with hair-like projections called called cilia,cilia, and they eat the other two types of and they eat the other two types of protozoa as well as bacteriaprotozoa as well as bacteria..

Ciliates are found in every aquatic habitat.Ciliates are found in every aquatic habitat.

Members of the genus Members of the genus Paramecium Paramecium are the are the most commonly studied ciliates. most commonly studied ciliates.

Phylum Ciliophora

• Called plankton & serve as a food source• Form protective cysts to survive

unfavorable conditions• Members include the Paramecium,

Vorticella, & Stentor• Have 2 types of nuclei --- smaller

micronuclei & larger macronuclei• Macronucleus controls asexual

reproduction by mitosis• Can reproduce sexually by conjugation

(two paramecia join together & exchange DNA)

Phylum Ciliophora

*Clear, elastic covering of cell membrane called pellicle *Pellicle made of protein for protection *Use cilia to swim & obtain food (algae & bacteria) *Have 2 contractile vacuoles to pump out excess water

Path of food *Cilia sweep food into oral groove where mouth located at the bottom *Food enters short tube called gullet into food vacuoles where it’s digested *Wastes leave through anal pore

Paramecium

The third group is theThe third group is the Flagellates Flagellates < <flah-flah-geh-letsgeh-lets>, of the Phylum >, of the Phylum SarcomastigophoraSarcomastigophora. Flagellates are . Flagellates are generally the smallest of the protozoa generally the smallest of the protozoa and have one or several long, whip-like and have one or several long, whip-like projections called flagella poking out of projections called flagella poking out of their cells.their cells.

Flagellates use their flagella to move.Flagellates use their flagella to move. It is a flagellate in the intestines of It is a flagellate in the intestines of

termites which enable them to eat wood. termites which enable them to eat wood. Both organisms benefit…..what kind of Both organisms benefit…..what kind of relationship do they have?relationship do they have?

Phylum Sarcomastigophora

Phylum Sarcomastigophora • Many are free-living that are found in lakes and ponds

• Others are parasites like Trypanosoma and

Trichonympha• Trypanosomes live in the blood of fish, amphibians,

reptiles, birds, and mammals. It is carried from host to host by bloodsucking insects.

• African Sleeping Sickness is transmitted to people by the bite of a Tsetse fly.

• Trichonympha lives symbiotically inside termites & digests

cellulose

Trichonympha

Lives in theintestines of a Termite.

The last of the phyla includes at least 4,000 The last of the phyla includes at least 4,000 species that have no means of locomotion. species that have no means of locomotion. Phylum Apicomplexa, once referred to as Phylum Apicomplexa, once referred to as Sporozoans, are parasites. Many have more Sporozoans, are parasites. Many have more than one host.than one host.

Form sporesForm spores Immature sporozoans are called Immature sporozoans are called sporozoites sporozoites

and live in body fluids of hosts.and live in body fluids of hosts. PlasmodiumPlasmodium is transmitted by mosquitoes & is transmitted by mosquitoes &

causes causes malaria.malaria.

Phylum Apicomplexa

• Plasmodium sporozoites enter the bloodstream, travel to the liver, divide & form spores called merozoites.

• Merozoites attack red blood cells and later form eggs & sperm that fertilize.

• New sporozoites migrate to the salivary glands of mosquitoes where they can be passed on to another person.

• Malaria can be controlled by controlling mosquito populations and it is treated with a drug called quinine derived from the Cinchona Tree in tropical rain forests.

Only certain species of mosquitoes of the Anopheles genus—and only females of those species—can transmit malaria.

Phylum Apicomplexa

Toxoplasmosis is an infection by a tiny parasite (Toxoplasma gondii) that can live inside the cells of humans and animals, especially cats and farm animals.

If you have been pregnant, you may already know it's important to avoid toxoplasmosis, which people can develop by cleaning the litter box of an infected cat or eating undercooked meat or other contaminated foods.

The Centers for Disease Control and Preventing (CDC) estimates that about 60 million people in the United States could have toxoplasmosis, but most won't have symptoms because their immune systems are strong.