Why I Chose this Chapter:
Honestly, I had been given this chapter by force for a previous project. I was not too trilled because I really wanted Chapter 31 (Fungi), but had to suck it up and just do my best. After only reading the first two pages I was hooked, these little organisms were more than just boring tiny little creatures they're all over the place! And in fact protists were 100-times more interesting than I had originally thought. So needless to say, I truely enjoyed reading and learning about protists and jumped at the opportunity to help future students learn about this small but large group of organisms called protista.

Objective/ Summary of the Chapter:
The kingdom "protista" is not actually protista at all what it is an informal name given to eukaryotes that have a nuclei but are neither plants, animals, nor fungi. Biologists and just anyone in general refer to these organisms as protist more for convenience because could you imagine trying to explain to someone that a particular organism is a eukaryote but is neither plant, animal, or fungi (yah, that is both confusing and quite the mouth full).

Protists are categorized in six main subgroups:

It is important to know that the root of the eukaryotic tree is not known, and the list is put in no particular order because it is not known which subgroup came first, second, third, and so on. So, just because Excavata is shown on top and Unikonts on the bottom it doesn't mean that Excavata came first nor does it mean that Unikonts came last. If the base of the eukaryotic tree were known then scientists would be able to fill in those blanks.
  • In 2002 Alexandria Stechman and Thomas Cavalier of Oxford University proposed a new hypothesis on the root of the eukaryotic tree
    • Their hypothesis: unikonts were the 1st to diverge from other eukaryotes
    • Which proposes that animal and fungi belong to an early diverging group of eukaryotes and the protists that lack mitochondria diverged much later in the group.
    • However this hypothesis is controversial and requires more evidence

Here is important information about each subgroup, keep in mind the key concepts and the morphological characteristics, those are extremely impartant!


Endosymbiosis is important in Eukaryotic Evolution:
  • Endosymbiosis is the process in which certain unicelluar organism engulfs another cell, which lives within the host cell and ultimately becomes an oranelle in the host cell and then becomes an an organelle in the host cell
  • Evidence in eukaryotes indicate that heterotrophic eukaryotes an additional endosymbiont, a photosynthetic cyanobacterium that then evolved into plastids


How Protists play a key roles in ecological relationiships:
  • As I mentioned earlier these guys can be found almost everywhere; water, moist terrestrial habitats (damp soil and leaf litter), ponds, oceans, lakes, and they even attach to rocks!
  • Many protists have symbiotic relationships with other species
  • An example would be photosynthetic dinoflagellates provide nourishment to their symbiotic partners, the coral polyps that build coral reefs
  • Many protists are also producers, which are important to form the foundation of food webs, and if factors affect producers it can dramatically afffect the entire community

Key Vocab. Words:
  • Protist: eukaryote with a nucleus but is not an animal, plant, nor fungi
  • Mixotroph: organisms that use a combination of photosynthesis and hetertrophic nutrition
  • Secondary Endosymbiosis: process in eukaryotic evolution in which a hetertrpohic eukaryote engulfed a photosynthetic eukaryotic cell which then survived in a symbiotic relationship inside the hetertrophic cell
  • Symbiotic Relationships: relationship between two organisms in which both benefit from each other
  • Producers: organisms that use energy from light (or inorganic chemicals) to convert carbon dioxide into organic compounds

Here's links to information about protists you might find interesting:
Self Quiz:
  • You can test your knowledge about protists on the mastering bio website, just log in or create a student account, choose Chapter 28:Protist, scroll down to were it says self quiz, and do your best.

Sections from the Chapter you may want to read:
  • From Comcept 28.1
    • The introduction
    • Endosymbiosis in Eukaryotic Evolution
    • Five Subgroups of Eukaryotes
  • From Concept 28.2
    • The introduction
    • Diplomonads and Parabasalids
  • From Concept 28.3
    • The introduction
    • Alveolates
    • Apicomplexans
    • Diatoms (just for fun this section was really interesting)
    • Golden Algae
    • Brown Algae
  • From Concept 28.4
    • The introduction
    • Radiolarians
  • From Concept 28.5
    • Red Algae
    • Green Algae
  • From Concept 28.6
    • The introduction
    • Amoebozoans
    • Slime Molds
  • Concept 28.7
    • All of it! Don't worry it's an extremely short section.

And That's All You Have to Know About Protists!

Hope You Found
The Information Useful

earth-day.png(I just thought it was a funny picture)