Kingdom Protista

 

What makes a protist a protist?

·         Protist=”the very first”

·         Eukaryotic cells

·         Generally microscopic

·         Can be found wherever life exists

·         Primarily unicellular

·         Primarily reproduce asexually

·         Important to the biosphere

 

 

Protist Classification

Highly debated: complex and diverse group of organisms that changes with every new study and find

Can be divided into groups based on the method of nutrition

·         Photoautotrophs

·         Heterotrophs by absorption

·         Heterotrophs by ingestion

 

Where are protists found?

 

 

Locomotion

·         Cilia

·         Flagella

·         Pseudopodia

 

Some other protozoan structures

·         Chloroplasts

·         Pyrenoid

·         Eyespot

·         Lysosomes

·         Cytosome

·         Cytopyge

·         Contractile vacuole

·         Pellicle

·         Test

·         Trichocysts

·         Toxicysts

 

Asexual Reproduction

·         Binary fission

 

·         Budding

 

 

·         Multiple fission (schizogony)

 

Protozoan colonies

·         Produced when the daughter individuals, derived asexually, remain associated instead of moving apart and living a separate existence

 

Other reproductive activity

·         Conjugation: method to introduce genetic variation among offspring by transferring genetic information from one cell to the next

·         Sexual reproduction through the formation of gametes

·         Formation of spores or cysts

Life Cycles

Mitosis results in two cells that have the same number of chromosomes as the parent cell. Draw below:

 

 

Meiosis results in four cells that have half as many chromosomes as the parent cell. Draw below:

 

 

Draw a typical animal life cycle:

 

 

 

 

The three types of life cycles listed below occur in protists.

Haploid life cycle: Zygote is in 2n stage, meiosis produces spores, individual is always n (so, organism appears as two individuals until meiosis occurs again). The multicellular form (adult) is haploid.

 

 

 

 

Diploid life cycle: Individual is always 2n; meiosis produces gametes; what we’re most familiar with, but only a few protists have this cycle (some brown algae). The multicellular form (adult) is diploid.

 

 

 

 

Alternation of Generations: sporophyte is 2n, meiosis produces spores; gametophyte is n generation (in protists, haploid and diploid generations have the same appearance). A multicellular haploid generation alternates with a multicellular diploid generation.

 

 

 

 

 

I. Photoautotrophs (plant like): 6 Major Phyla

·         Phylum Chlorophyta: Green Algae

o   Unicellular:

§  Chlamydomonas:

§  Acetabularia:

·         Hammerling's experiment (1953) with Acetabularia showed that the nucleus of a cell contains the genetic information that directs cellular development.

o   Filamentous:

§  Spirogyra:

o   Colonial:

§  Volvox:

·         Phylum Rhodophyta: Red Algae

o   Porphyra

·         Phylum Phaeophyta: Brown Algae

o   Laminaria

o   Sargassum

·         Phylum Chrysophyta: Goden Brown Algae, Yellow-Green Algae, and Diatoms

o   Diatoms

·         Phylum Pyrrophyta: Dinoflagellates and Cryptomonads

o   Dinoflagellates

§  Noctiluca

§  Ceratium

§  Gymnodinium brevis

·         Phylum Euglenophyta: Euglenoids

o   Euglena

II. Heterotrophs by absorption (Fungus-like)

·         Phylum Oomycota

o   Water molds

o   Phytophthora infestans

III. Heterotrophs by ingestion (Animal-like)

·         Phylum Zoomastigophora: Zooflagellates

o   Trypanosoma

o   Giardia

o   Trichomonas

·         Phylum Rhizopoda: Amoeboids

o   Naeglerea fowleri

·         Phylum Foraminifera and Phylum Radiolaria: Foraminiferans and Radiolarians

o   Foraminiferans:

·         Nummulites

o   Radiolarians:

·         Phylum Ciliophora: Ciliates

o   Paramecium

o   Suctoria

o   Stentor

o   Ichthyophthirius

·         Phylum Apicomplexa: Sporozoans

o   Pneumocystis carinii

o   Plasmodium vivax

o   Toxoplasma gondii

·         Phylum Myxomycota

o   Plasmoidal slime molds

·         Phylum Acrasiomycota

o   Cellular slime molds