In this exercise we will explore the Internet to learn about protists!
The Protists are extremely difficult to classify!
Protists are not prokaryotes!
Protists are typically, single celled eukaryotes…
At least they are always eukaryotes, but what about single celled?
There are exceptional organisms that are difficult to classify as animal, plant or fungus:
Therefore some scientists dump these exceptional cases into the Protist kingdom.
Consider these “exceptional cases” as “Missing Links” between the single celled and muti-cellular kingdoms! In the mean time, scientists are arguing with each other about classifying and there seems to be a trend to exclude multi-cellular organisms from the Protist kingdom in the future!
To review:
Monerans are the most primitive kingdom.
Monerans are all prokaryote and are all single-celled!
Protists are also single celled (according to a growing consensus) and are all eukaryote.
Iimage from W.H. Freeman and Sinauer Associates, used by permission.
Notice the three remaining kingdoms evolved from Protista!
Before answering the questions below, make sure you have understood the information on the preceding links (especially the sentence immediately above!):
What is a prokaryote?__________________________________________
What is a eukaryote? ____________________________________________
The diagram above is different from your text! These scientists believe in a six-kingdom system.
What old kingdom was divided into two separate kingdoms? ________________
According to the above diagram, Protista overlap with three other kingdoms:
This indicates the three multicellular eukaryotic kingdoms evolved from Protista the first eukaryotic kingdom.
Monerans however do not overlap with Protista!
This indicates that Protista as eukaryotes evolved from Moneran Prokaryotes!
According to this last chart, there are three kinds of Protists. What are they?
___________________ _______________________ ___________________
Review :
Identify
each kingdom, and in each box; write which have cell walls, as well as which are
autotrophe, heterotrophe or both, and indicate waht is happening above and below
the doted lines
|
|
|
|
|
|
|
|
|
|
|
|
Protista are marvelous, because they defy all our feeble and puny attempts to classify them!
Click on the pictures below:
Euglena have gullets and lack a cell walls like an animal cells. (heterotrophic ingestion?)
Euglena have a chloroplasts like plant cells (autotrophic photosynthesis)
And Euglena have been known to lose their chloroplasts forcing Euglena
to absorb nutrients from its environment (Heterotrophic absorption)
Define the following:
Consequently, Euglenoids can be classified as animal, plant and fungus!
Let us concentrate on the Euglenoids for a while:
Two reasons the Eugleonoids are considered to be animal-like:
__________________________ _____________________________
Even though Euglena has a gullet, it does not ingest its food.
The two ways Euglenoids can eat are:
__________________________ _____________________________
http://www.cells.de/cellseng/medienarchiv/archiv/bp1c1562d/1562_b41.htm
The two ways Euglenoids move? ____________________ __________________
Are the flagella on the front end or the back end of a euglena? _________________
Euglena wants to move towards the light for photosynthesis!
How does Euglena orient itself so it can move towards the light?
Explain in your own words: _______________________________________________
_______________________________________________________________________
Euglenoids keep their shape because of a pellicle.
Define pellicle: __________________________________________________________
________________________________________________________________________
Let us move on to an animal-like protist: (click on pictures)
Ciliates are an example of animal-like Protists covered with up 17,000 cilia beating from 40 up to 60 times a second in a coordinated fashion!
Cilia can be used for locomotion or for feeding. A movie of a moving paramecium!
http://micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/paramecium/index.html
The following link is a rather large site on Protista.
Scroll down until you find ciliates and answer the following questions:
What is the difference between a macro- and a micro- nucleus?
________________________________________________________________
How do ciliates deal with osmosis and the influx of excess water?
________________________________________________________________
How do ciliates eat and excrete wastes?
________________________________________________________________
What are trichocysts? ______________________________________________
Click on the image below to observe the sex life ( XXX )of Paramecia!
Cut and paste the following address into a url address box:
http://membres.lycos.fr/mad8/images/conjug.gif
Which nuclei are involved in conjugation ? ______________
Doe these nuclei fuse? ____________________
How many nuclei are produce in each cell? ______________
Each parent cell produces how many daughter cells? _______
Another Protist Phyla we shall examine is called Sacodina (click on picture)
A typical organism is the ferocious predator Ameoba proteus.
Their cytoplasm can exist in to states: liquid “sol” and semi-solid “gel”; so-called endoplasm and ectoplasm
A quick link explaining how they move.
And
Again, but this time in real life
http://micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/amoeba/index.html
http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/protista/movies/Amoeba.MOV
What is a pseudopod? ________________________________________
What is a Foraminifer? _________________________________________
We all in awe of the fossils that remind us of the GREAT AGE OF DINOSAURS!
Considering that the white cliffs of Dover are the deposits of Forminiferan fossils,
should we not be even more impressed with the even more SPECTACULAR GREATER AGE OF PROTISTS, when they alone ruled the world?
But before we get too carried away…
Remember how these little single celled organisms love to exploit humans when given a chance!
Name a Human disease caused by an Amoeba? _________________________
Name the tissues and organs involved in this disease? ________________________________________________________________
Finally, the last animal Protist, parasitic organisms that cannot move on their own because they do not need to!
Name two human diseases caused by The Sporozoans?
__________________________ ___________________________
A Sporozoan has a different life cycle from the disease-causing amoeba you saw earlier. What is the major difference in life cycles?
________________________________________________________________________
To Review:
In classifying Protists,
the first dichotomy is classifying protists as either: __________ ________ __________
the second dicotomy is defining how they move: __________ ________ __________
best link available on Protista:
http://ublib.buffalo.edu/libraries/units/sel/bio/evolweb2.html#Protista
We forgot to mention the missing link between Protists and the multicellular kingdoms:
The
Slime Molds! (click on image to observe cytoplasmic streaming!)
