CLASSIFICATION OF LOWER ORGANISMS

Remember:  There are ___ Kingdoms for all organisms  ____________, _______, _______, ________, __________, ______________  “_______ ___________” are generally the Eubacteria, Archaebacteria, Protista and Fungi

Definitions  _________: the taxon containing closely related classes  ___________: The evolutionary history of a group of organisms that share a common ancestor

Protists - Introduction  Single celled _____________  Appeared approximately 1.5 billion years ago  species, all very diverse in cell structures, patterns of nutrition, reproduction and habitats  Their ___________is very complex and difficult to classify  To simplify in this class, protists have been broken down/classified based on their ______________ pattern: animal-like, fungus-like and plant-like

Animal-Like Protists  Also called ____________  All are ___________ - they eat and ingest material from their surroundings  Are 4 phyla of protozoa, classified by their type of ____________  Numerous in types of species and population numbers, similar to bacteria

Animal –Like Protists: Zooflagellates  Phylum Mastigophora  Possess 1 or more ______ to help them move  Feed on other ________ or are internal parasites on animals  Reproduced _________ via longitudinal fission  Example: Trypanosoma gambiensis causes sleeping sickness that destroys RBCs, other tissues and one’s nervous system until the person loses consciousness

Animal-Like Protists: Amoebas  Phylum Sarcodina  Most are free-living forms  No set _____ ________  _____________ (projections of cytoplasm) enable them to move and feed through ___________ (engulfing organisms with their pseudopods)  Some are parasitic Example: Entamoeba causes amoebic dysentery, found in the water in tropical regions

Animal –Like Protists: Ciliates  Phylum Ciliophora  Covered with hairlike projections called _____  Rigid outer covering called _______ maintains their shape (amoebas don’t have this)  All ciliates are aquatic heterotrophs  ___________ is an example

Paramecium Digestion  Beating of its cilia sweeps food into ____ ________  Membrane pinches off, surrounds food and a food vacuole is formed  Food vacuole joins up with a _________ which breaks down the food with digestive enzymes  Usable products are absorbed in cytoplasm, undigested food is removed via ___________

Paramecium & Structure  Have 2 types of nuclei – large ______nucleus and smaller ______nucleus  Reproduction by _______________ (asexual)  Micronucleus (ei) divide by mitosis and macronucelus simply pinches apart to produce two daughter macronucleus  Paramecium also use sexual reproduction via ____________

Animal-Like Protists: Sporozoans  Phylum Sporozoa  Produce ______ during asexual reproduction  Sporozoa are non-motile and parasitic; get nutrients from bodies of hosts  Best known sporozoan is genus Plasmodium that causes _________

Fungus-Like Protists  Also called....SLIME MOULDS!!!!  All are __________ and most are ___________that feed on dead plants and animals by endocytosis  Live in cool, damp habitats

Fungus-Like Protists: Acellular Slime Moulds  Single celled  Most of life is a wall-less mass of cytoplasm with many nuclei  Cytoplasm moves using ____________ (network of strands)  Reproduce using _________; spores scatter and germinate

Fungus-Like Protists: Cellular Slime Mould  Live in fresh water, damp soil or decaying matter  Move like ___________ cells  When food is scarce, they form a large ____________ mass and eventually release spores

Fungus-Like Protists: Water Moulds  Most live in _______; some on land  May have seen growing on dead fish as whitish cottony substance  Most land species decompose dead matter which is good, but few are parasitic to plants  ________________ in mid 1800s caused by Phytophthora infestans

Plant-Like Protists  Are species of protists that contain __________and carry out ____________, and so they resemble plants  We look at Euglenoids and Algae

Plant –Like Protists: Euglenoids  Are unicellular flagellates and many members of this group _________________ to produce food  Species called Euglena gets fed in 2 ways  In sunlight it is ______________ (photosynthesis)  In dark feed as ____________ on dead organic material in water

Plant –Like Protists: Algae  Resemble plants because they have chloroplasts that have chlorophyll  Some are single-celled, some live in colonies, some are multicellular  Are ___ main groups of algae; we discuss 3 here

Algae: Diatoms  Have golden colour due to yellow-brown pigments in their shells  Outer covering is made of two halves  Each species has a characteristic shape  Abundant in _______; also classified as _______________

Algae: Dinoflagellates  Are single-celled algae, have 2 ________  Most are ___________  Abundant in marine environments  Each species has a specific shape  Tend to be _____________: when surrounding water is agitated, they give off light!!  Reproduce by __________

Interesting to Know....  Rapid population growth called an ______________  When dinoflagellate Gonyaulax polyhedron blooms it’s called a ___________

Algae: Green algae  Can be single celled or colonial  Each cell has 2 _________ that move the cell around  Ancient green algae are thought to have given rise to the first plants because they have ____________ in their cell walls and their ____________ are similar to those of plants  Multicellular algae known as ___________

Algae: Green algae Colony of Algae (Volvex) Giant Kelp (multicellular Algae) can grow to 100 m and has the fastest growth rate of any organism.