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 115 000 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 24 000 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.