Kingdom Protista

Kingdom ProtistaBasic Characteristics: - eukaryotes

- most are unicellular

- most are heterotrophs

- Habitats: aquatic habitats or moist soil

Origin of Protista

• Some scientists believe that mitochondria and chloroplasts started out as prokaryotes that lived inside larger prokaryotes

• Endosymbiosis – one organism lives in a larger organism

Characteristics used for classification

• nutrition – heterotrophic; autotrophic; saprophytic

• cell number – unicellular or multicellular

• Motility

– ability to move and movement structures

- These structures include flagella, cilia, and pseudopodia

Reproduction

Asexual (most common):

- Binary fission (unicellular)

- Multiple fission (divide into more than 2 cells)

Sexual:

- Conjugation (genetic information is swapped and stored in a 2nd nucleus)

See page 504

1. ANIMAL-LIKE PROTISTS: Protozoans

- unicellular

- heterotrophic or parasitic

phagocytosis – engulfing food

– motility: pseudopods, cilia, flagella or none

- freshwater (amoebas) or marine

marine – salt water

ex: amoeba, paramecium

2. PLANT-LIKE PROTISTS (ALGAE)

- unicellular, colonial, multicellular

- nutrition: autotrophs (phototrophs) and heterotrophs

* have chlorophyll

- habitat: freshwater or marine

- Unicellular phyla are all called phytoplankton

Ex: volvox, kelp, seaweed, euglena

3. FUNGUS-LIKE PROTISTSSlime Molds

- nutrition: heterotrophic, parasiticphagocytosis

- motility: flagella, pseudopodia- habitat: moist soil/ organic matter - - a “mass of cytoplasm that can ooze around obstacles”

Fungi Kingdom

 ·     Eukaryotes

·      Heterotrophic:

- most saprophytes

- some parasites

·       Most multicellular;

one is unicellular

·       Most sessile

Structure:

Chitin - a tough, flexible carbohydrate that makes up fungi cell walls

hyphae - small tubules filled with cytoplasm and nuclei; makes up multicellular fungi

Mycelium – an interconnected mass made up of hyphae

Septa – wall in hyphae with holes for the cytoplasm to flow through

Chitin → hyphae → myclium

Hyphae produce enzymes that are secreted into the environment and then nutrients are reabsorbed through hyphae

Asexual Reproduction:

1)     Multi-cellular –regeneration; (single celled- mitosis & cell division)

     Budding - new organism forms from small piece of mycelium

      Asexual spore formation from fruiting bodies

Spores spread by wind,

water, animals (*most common)

Sexual reproduction

– hyphae fuse together to form spores

- possible in common molds, club fungi, and sac fungi only

Ex: molds, mushrooms, yeast, ringworm, athelete’s foot

Nutrition: Fungi obtain nutrients by digesting organic matter externally before absorbing it

Impact:

       environment - breaks down dead organisms

       symbiosis

a)   fungus + cyanobacteria = lichen;

fungus offers protection, cyanobacteria offer food

b) plant growth – fungus grows on root tips of some plants

   human

food source, medicine (penicillin), food processing, genetic engineering of proteins

   disease

destroy plants and trees

property damage to wood structures

human infection