Informal name for a group of eukaryotic organisms that are difficult to classify.
Belong to the Domain Eucaria.
Mostly unicellular and microscopic.
Genetic evidence shows that some are more related to plants, animals, or fungi than to other protists.
The protist group is like the drawer where we put everything we don't know where it goes.
The group with the greatest structural and functional diversity of eukaryotes.
Unicellular and multicellular organisms.
Some organisms form colonies.
Sexual, asexual, or both types of reproduction.
Can live in terrestrial or aquatic environments, inside other organisms, or in dead organic matter.
Nutritional diversity:
Photoautotrophs: Have chloroplasts and perform photosynthesis.
Heterotrophs: Need to feed on organic matter.
Mixotrophs: Combine photosynthesis with heterotrophic nutrition.
Nucleus: Contains the genetic material, separated from the cytoplasm by a membrane.
Organelles: Each performs specific functions.
Mitochondria: Organelle specialized in aerobic respiration.
Cytoskeleton: Allows the cell to alter its shape to move, eat, and grow.
Carry out Mitosis.
Chromosomes organized by histones.
Endosymbiosis: Relationship between two species in which one organism lives inside the cells of the other organism (the host).
Mitochondria and chloroplasts are derived from prokaryotic organisms that were swallowed by the ancestor of eukaryotic cells.
Mitochondria: Endosymbiosis of an alpha proteobacteria (aerobic).
Chloroplasts: Endosymbiosis of a cyanobacteria (photosynthetic).
"Protoeukaryotic" host cell: Related to archaea.
Folds in the plasma membrane give way to the first organelles in a proto-eukaryotic cell.
First endosymbiosis: the cell swallows an aerobic bacterium that will become the mitochondrion.
Second endosymbiosis: the eukaryotic cell swallows a cyanobacterium that will become the chloroplast.
Plastid
Green alga
Euglenids
Inner plastic membrane
Chlorarachniophytes
Nucleomorph
Outer plastid membrane
Nuclear pore-like gap
Dinoflagellates
Red alga
Plastid
Stramenopiles
Mitochondria:
Have their own DNA, a circular chromosome.
Ribosomes and tRNA very similar to those of prokaryotes.
Their shape is the same as that of alpha-proteobacteria.
Double membrane.
Divide independently of the eukaryotic cell by binary fission.
Has lost genes, which explains why it cannot live independently.
Chloroplasts:
Have their own DNA, a circular chromosome.
Ribosomes similar to those of cyanobacteria.
Double membrane and some a layer of peptidoglycan between both membranes.
Divide independently of the eukaryotic cell by binary fission.
Has lost genes, which explains why it cannot live independently.
Archaeplastida
Unikonta
SAR (Stramenopila, Alveolata, Rhizaria)
Excavata (Formerly called Discova)
Autotrophs.
Unicellular, unicellular that live in colonies, and multicellular.
Sexual and asexual reproduction.
Cell walls with cellulose.
Life cycle alternation of generations.
Group that includes terrestrial plants.
Heterotrophs.
Many show lobed pseudopods that they use to move and eat (phagocytosis).
Some are parasites.
Unicellular and multicellular.
Sexual and asexual reproduction.
Includes Slime molds.
Amoeba movement by pseudopods
This type of movement is possible thanks to the cytoskeleton that these organisms possess.
Heterotrophs.
Name comes from its single flagellum in the posterior part.
The protists in this group are unicellular and colonial.
Includes choanoflagellates.
Filters.
Sexual and asexual reproduction.
Aquatic.
Heterotrophs and mixotrophs.
Some have gained organelles by secondary endosymbiosis.
Includes amoebas with fine pseudopods like needles or threads.
Some create calcium carbonate or silica armor.
All unicellular.
Sexual and asexual reproduction.
Aquatic and some parasitic.
Includes Alveolates and Stramenopiles.
Arise from secondary endosymbiosis with a red algae.
Some have lost this plastid.
Autotrophs, heterotrophs, and mixotrophs.
Unicellular and multicellular.
Sexual and asexual reproduction.
Complex life cycles.
Aquatic and some parasitic.
They are characterized by having membrane-bound sacs (alveoli) just below the plasma membrane.
This group includes:
Dinoflagellates
Apicomplexes
Ciliates
red tide
Bioluminescent bays
All are parasites of animals and some cause serious diseases.
One end of the cell contains a complex of organelles specialized to penetrate host cells.
They have complex life cycles.
Require two or more hosts to complete it.
Apicomplex that causes malaria.
It has two hosts: Mosquito of the genus Anopheles and Humans
Includes some of the most important photosynthetic organisms on the planet.
Diatoms
Golden algae
Brown algae
Important producers of O2$$O_2$$ on the planet.
Sequester carbon at the bottom of the sea for a long time.
Unicellular and multicellular.
Pneumatocysts: air-filled vesicles that allow these algae to float in the water
General characteristics
Feeding grooves (excavated).
Multiple flagella.
Autotrophs, heterotrophs, mixotrophs and some parasitic.
Protists commonly found in pond waters.
They have two flagella that emerge from one side of the cell.
They are mixotrophs.
They have no cell wall.
Protists Notes