Post on 19-Jan-2016
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.