Features Ecology Evolution Extras







Diplomonadida- Parabasala

Key Characteristics: They lack mitochondria.

A. Diplomonadida

• Two separate nuclei, simple cytoskeleton, and no plasmids
• Example: Giardia lamblia, which is a parasite that infects the human intestine

Giardia Lamblia


B. Parabasala

• Has flagella and undulating membrane
• Example: Trichomonas vaginalis, which infects the vagina

>>Back to Top <<


Key Characteristics: Most are unicellular. Many swim by means of a single flagellum. They are not encased in a cell wall so they are flexible as well as motile. They are photosynthetic, heterotrophic, and mixotrophic flagellates.

A. Euglenophyta

• Uses paramylon as storage
• Members of the group have chloroplasts, however they are neither plants nor animals.
• Example: Euglena

B. Kinetoplastida

• Has a single mitochondria, connected to the kinetoplast, which is a unique organelle that houses extra nuclear DNA
• Some kinetoplastids are symbiotic, others are pathogenic to their hosts
• Example: Trypanosoma, which causes the sleeping sickness in Africa. They are able to alter their molecular structure in order to avoid being killed by its host immunity system


>> Back to Top <<


Key Characteristics: Under the surface are alveoli (membrane- bound cavities). They all have a system of saclike structures on the inner surface of their plasma membrane as well as close homology in their gene sequences.

A. Dinoflagellata

• They hang near the water surface; provide the foundation of most marine and many freshwater food webs
• Most are unicellular
• For some, the shape is reinforced by internal plates of cellulose. Two flagella in perpendicular channels in this “armor” which produces a spinning movement
• Example: Pfiesteria piscicida uses its toxin to stun fish and it feeds off their prey’s body fluids

A Dinoflagellate

B. Apicomplexa

• Parasites of animals
• These parasites spread as small infectious cells, sporozoites. One end of the sporozoite cell has complex organelles, made for penetrating host tissues and cells
• Example: Plasmodium, a parasite that causes malaria. It is also able to change its “face”, which is shown to the host’s immune system

The life cycle of Plasmodium vivax


C. Ciliophora

• Use cilia to move and feed
• Ciliates live as solitary cells in fresh water, have very short flagella’s and are the most complex cells
• Example: Paramecium


>> Back to Top <<


Key Characteristics: Most of the time the “hairy” flagella is paired with a smooth flagellum.

A. Oomycota

• Most are heterotrophic, which lack chloroplasts
• Examples: water molds, white rusts, downy mildews
• Water molds and relatives have cellulose for their cell walls, unlike true fungi (made of chitin). Decomposers, which grow on dead algae and animals (mostly in fresh water)
• White rusts and downy mildews live on land as parasites for plants. They are dispersed by windblown spores or form flagellated zoospores
• Similar “body plan” (mass of thin filaments) to fungi, but not closely to related. This shows evolution
• Extensive surface area for absorbing nutrients

B. Baccillariophyta

• Colors: yellow or brown
• Have unique glasslike walls, which consist of hydrated silica set in an organic matrix
• Reproduce asexually under mitotic sell division, most of the year
• Store food reserves in the form of a glucose polymer (laminarin)
• Found in both freshwater and marine plankton

C. Chrysophyta (golden algae)

• Color: yellow or brown based on their carotene and xanthophylls accessory pigments
• Cells are biflagellated (both attached near one end of the cell)
• Found in both freshwater and marine plankton
• Some are mixotrophic, absorbing dissolved organic compounds or food particles and bacteria by phagocytosis
• Most are unicellular


Golden Algae



D. Phaeophyta (brown algae)

• Multicellular
• Most live in marine or where water is cool
• Example: seaweed (analogous), cell walls composed of cellulose and gel- forming polysaccharides, important food source

>> Back to Top <<

Rhodophyta (red algae)

Key Characteristics: There are no flagellated stages; phycoerytherin pigment.

• Most are multicellular
• Have no flagellated stages in their life cycle
• Color: red because of phycoerythrin, an accessory pigment, however, they are not all red, depending on their water depth
• Most live in costal waters
• Depend on water current for fertilization
>> Back to Top <<

Viridiplantae (green algae)

Key Characteristics: They have plant type chloroplasts.

• Closely related to land plants, plant type chloroplasts
• Most live in freshwater, but some are marine species
• Sexual and asexual reproductive stages
>> Back to Top <<

Mycetozoa (slime molds)


Key Characteristics: They are neither fungus nor animal. The decomposers have complex life cycles with amoeboid stages. They use pseudopodia for feeding and movement.

A. Myxogastrida

• Color: yellow or orange
• Heterotrophic
• Plasmodium, the feeding stage of the life cycle as an amoeboid mass, which is a single mass of cytoplasm with many nuclei. Used to study the cell cycle. Cytoplasmic streaming helps distribute oxygen and nutrients
• Feeds on food particles by phagocytosis through soil, rotting logs or leaf mulch
• When there is no food left, stops growth and starts sexual reproduction

B. Dictyostelida

• Amoeboid feeding cells that combine to form reproductive colonies
• Haploid organisms
• Asexual reproduction
• No flagellated stages



>> Back to Top <<

Pseudopod (equipped protests of uncertain phylogeny)

Key Characteristics: They are pseudopodia that function in movement and feeling.

A. Rhizopoda

• Amoebas are unicellular and use pseudopodia to feed and move
• Some are free- living, others are important parasites
• Live in freshwater, marine and soil environments

B. Actinopoda

• Planktonic and their projections place as extensive area of cellular surface in contact with the surrounding water, which helps it feed and float
• Example: Heliozoans, freshwater and consist of chitinous unfused plates

C. Foraminifera

• Marine, live in sand or are attached to rocks/ algae
• Strands of cytoplasm extends through the pores of the shell which helps it function to swim, shell formations and feed

>> Back to Top <<