Kingdom Protista (2)Biology 11

Mr. McCallum

REVIEW TIME

Animal-like Protists (Protozoa)

Heterotrophs Must consume to gain nutrition

Holozoic Engulf their food

Saprozoic Absorb pre-digested or soluble nutrients through membrane

4 phyla Sarcodina Mastigiphora Ciliophora Sporozoa

Animal-like Protists (2)

Larger population numbers, and larger number of species overall than bacteria

Occupy a diverse range of moist habitats

Huge range/variability in size (micrometers to centimeters) Small red blood cell can contain a dozen

Usually undergo asexual reproduction Binary fission Can form cysts (hard protective covering over cell

membrane – resting/dormant cells)

Classification

Distinguished by their modes of locomotion Cilia, flagella, pseudopodia, etc.

Also: Types of organelles Life cycle Mode of reproduction Free-living or parasitic

1. Phylum Sarcodina

Free-living Few parasitic species in animal intestines

Thrive in fresh water, salt water, and soil

Use pseudopods (“false feet” – finger-like projections) Provide motility through extension and retraction Allow organism to feed by engulfing food particles

E.g.: Amoebas, foraminiferans, radiolarians, heliozoans

E.g.: Amoeba

Largest and least complex protozoan

Two layers of cytoplasm Ectoplasm: thin, semi-rigid

layer under plasma membrane Endoplasm: more fluid, fills

the inside of the cell

Named chaos chaos by Linnaeus Continuous movement of

endoplasm causing amoeba to constantly change shape

E.g.: Amoeba (2)

Feeds by phagocytosis Pseudopods flow around

and engulf food particles Food then enclosed in food

vacuole Contractile vacuole collects

excess water – discharges it through pore in plasma membrane

Asexual reproduction Binary fission Typically 1 division a day

2. Phylum Mastigophora Motile

Move through use of flagella (one or more!)

Free-living forms found in both fresh and salt water

Majority are parasitic Live within other organisms Causing disease in animals

Asexual reproduction Longitudinal fission

Flagellates also form cysts Way in which many parasitic forms are spread from host to host

E.g.: Giardia lamblia

Giardia lamblia = Beiber feverNOT QUITE…. BEAVER FEVER

E.g.: Giardia lamblia (Beaver Fever)

Parasite that causes stomach upset and diarrhoea

Can have more severe effects in some individuals

Cattle and wild animals often have the parasite

Infection occurs when we drink or eat food tainted with the feces of these infected animals BOIL WATER if consuming directly

from a stream

3. Phylum Ciliophora

Most complex and advanced of the protozoans

Characterized by cilia Hair-like projections Shorter and more abundant than flagella Can cover the entire organism

Motile organisms have cilia synchronized for swimming Non-motile (sessile) organisms use cilia for attachment

Can undergo asexual (binary fission) or sexual reproduction (conjugation)

Live in both freshwater and marine habitats

E.g.: Paramecium

REVIEW TIME

E.g.: Paramecium

Most commonly studied ciliate

Oral groove contains mouth Connects to gullet Cilia in gullet sweep bacteria

and food particles into the cavity

Digestion takes place in food vacuole Waste expelled through anal

pore

Excess water collected in contractile vacuole

E.g.: Paramecium (2)

Two nuclei Large macronucleus – controls majority of cell

activities Smaller micronucleus – involved with reproduction

Reproduction often asexual (binary fission), can undergo sexual (conjugation) After conjugation, daughter cells undergo binary

fission

Defence mechanism Hundreds of poison-laden barbs (trichocysts) can be

discharged to drive away predators and capture prey

4. Phylum Sporozoa Lack means of independent locomotion

Some have flagella while maturing

Display complex life cycles

Exclusively parasitic Depend exclusively on body fluids of host for movement

Simple structure with fewer organelles and specialized structures

Characterized by a spore-like stage Reproductive cells that can produce a new organism without fertilization (sporozoites) In cases where two hosts are involved – reproduction is sexual in one host, asexual in the

other host Insects are frequently vectors – responsible for transmission

E.g.: Plasmodium

Notorious P.R.O.T.I.S.T. Responsible for causing malaria in humans, other

mammals, and birds

Malaria is a disease caused by the plasmodium parasite (phylum Sporozoa) Transmitted by the female anopheles mosquito Nearly half a billion people get Malaria each year – nearly

one million die of the disease Sub-Saharan Africa suffers 90% of all Malaria deaths

3 reasons why we still haven’t gotten rid of malaria

List the three reasons Sonia Shah believes are responsible for the prevalence of malaria in modern day society…

Be PREPARED to discuss these, along with any other questions/facts relating to malaria!

Fungi-like Protists

Heterotrophs, decomposers, and external digesters

Exhibit complex life cycles and exist in various cellular forms

1. Gymnomycota (Slime Moulds)

Prefer cool, shady, moist places Often under rotting logs, fallen leaves

Leave slimy trail as they move along the ground

At some point in life cycle resemble protozoans (amoeba-like, have flagella, etc.) At other points, they produce spores

Do not always remain as single celled organisms

Becoming multicellular is a TREMENDOUS advancement! Lays groundwork for cell specialization

2. Oomycota (Water Moulds)

Found notably in fresh water environments As well as upper surface of moist soil E.g.: Downey mildews and white rusts

Produce filamentous hyphae

Decomposers

Create a table to COMPARE/CONTRAST the three groups of PROTISTS that we have examined as a class (plant-like, animal-like, and fungi-like).

Be sure to include EXAMPLES OF ORGANISMS that we have discussed, as well as the MAIN SIMILARITIES and the MAIN DIFFERENCES between and within these groupings.