13.1 – Kingdom Protista

Kingdom ProtistaKingdom ProtistaCharacteristics:EukaryotesUnicellular and multicellular

organismsConsidered “left-overs” of

organisms:◦Consist of eukaryotic organisms that

do not fit into Kingdom Fungi, Animalia or Plantae

◦Protists are not animals, plants or fungi

ClassificationClassificationKingdom Protista consists of diverse

species that share similarities with other 3 kingdoms but do not meet all the requirements to fit into those kingdoms

Classifying protists is extremely difficult as there is more than 1 accepted way of separating them

General method is classifying protists by their nutritional patterns:◦ Animal-like protists◦ Plant-like protists◦ Fungi-like protists

Animal-like ProtistsAnimal-like ProtistsReferred to as protozoansProtozoans are

◦Unicellular organisms◦Heterotrophs - they eat or ingest

materials from their surroundingsProtozoans are not categorized

into a taxonomic group. This is a term used to describe animal-like protists that may be distantly related but share a set of characteristics.

Types of ProtozoansTypes of ProtozoansProtozoans are described and grouped

according to their method of movement.Heterotrophs – ingest small food particles

and digest it inside food vacuoles containing digestive enzymes

Do not have a cell wall

4 ways to describe a protozoan:ZooflagellateAmoebaCiliateSporozoan

ZooflagellatesZooflagellates

Possess 1 or more whip-like structures called flagella

Flagella help with movement of the protist in water

CiliatesCiliatesCiliates are aquatic

protists covered with cilia

Cilia – hair-like projections that assist protists with movement in water and with gathering food

Watch video:http://www.youtube.com/watch?v=Paed6uTdpQA

AmoebaAmoebaNo particular body shapeCreate pseudopods – temporary

projections of cytoplasmPseudopods help protist to move and

feed on other organisms

Watch Amoeba Video:http://www.youtube.com/watch?v=W6rnhiMxtKU&feature=related

• Intake food through process of endocytosis – engulf organism and form food vacuole

SporozoansSporozoansNon-motile protistsProduce spores during

reproduction

Plant-like ProtistsPlant-like ProtistsPlant-like protists are those that

resemble plants because they are photoautotrophs.

They contain chlorophyll and carry out photosynthesis

Unicellular or multicellular protistsSome plant-like protists have cell walls made up of polysaccharides and others do not have cell walls

Types:EuglenoidsAlgae

EuglenoidEuglenoidUnicellularContains flagella

for movementPhotoautotroph

during the day – undergoes photosynthesis

Heterotroph at night – feeds on dead organisms

Question: Why can euglenoids not be classified in Kingdom Plantae?

AlgaeAlgaeUnicellular or

multicellular

Photoautotrophs – have chloroplast and carry out photosynthesis

6 different groups of algae

Question: Since most algae are aquatic, provide a reason why algae are “plant-like” and not plants?

ReproductionReproductionAnimal-like and plant-like protists can

reproduce sexually and asexually.

Asexual ReproductionProtists reproduce by binary fission.

1 parent cell divides to produce 2 identical daughter cells

Sexual ReproductionOther protists can reproduce by

conjugation. Mates exhange DNA.

ReproductionReproduction

Binary Fission Conjugation

ConjugationConjugation

Question: As a eukaryotic cell, how would conjugation be more challenging vs prokaryotic cells undergoing conjugation?

Protists in our Everyday Protists in our Everyday LivesLivesParasitic protists can cause diseases when it they come into contact with the human body◦Example: malaria, sleeping sickness,

dysenteryAlgae

◦Food indusry Seaweed can be eaten. Example: sushi Used as food additives in the manufacturing

of food products. Example: beta-carotene◦Medicine

Used for curing arthritis, influenza, tuberculosis