Protists are a diverse group of eukaryotic organisms that exist as unicellular, colonial, or multicellular forms. They show characteristics of plants, animals, and fungi and have ancestry from multiple sources. Major protist kingdoms include Archaezoa, Euglenozoa, Alveolata, Stramenopila, and Rhodophyta. The Kingdom Protista is considered polyphyletic due to its varying origins.

1. List the characteristics of protists.
They are the earliest eukaryotes  showed
up a billion years before the others
Age  2.1 billion years
There are 60,000 living species
Exist as unicellular, colonial, and
multicellular
Aerobic, cilia & flagella, asexual or sexual
Bottom line: a VERY diverse group 

2. Explain what is meant by the statement that
the Kingdom Protista is a polyphyletic group.
Polyphyletic = ancestry from several possible
sources or directions
Example:
Protists are  animal-like
plant-like
fungus-like 

3. List five candidate kingdoms of protists
and describe a major feature of each.
• Archaezoa  lack mitochondria
• Euglenozoa  are both autotrophic and
heterotrophic flagellates
• Alveolata  have subsurface cavities (alveoli)
• Stramenopila  diatoms, golden brown algae,
and water molds
• Rhodophyta  red algae; lack flagella 

4. Life Cycle overview
Sporophyte  generally the adult form of an
organism; exists as a diploid (2n); makes spores
(ex: humans)
Gametophyte  generally an intermediate step
before fertilization; exists as a haploid (n);
makes gametes (ex: sperm & eggs) 

5. Outline the life cycles of Chlamydomonas,
Ulva, and Laminaria and indicate whether
the stages are haploid or diploid.
• Chlamydomonas  at maturity it is a single haploid
cell
- asexual at first, then sexual only if stressed,
creating a diploid zygote
2. Ulva  diploid sporophyte and haploid gametophyte
3. Laminaria  sporophyte (2n) with sporangia makes
zoospores (n) which make gametes (n) and then
fertilization to get diploid sporophyte again 

6. Distinguish between isogamy and oogamy;
sporophyte and gametophyte; and isomorphic
and heteromorphic generations.
Isogamy  when gametes are morphologically
indistinguishable
Oogamy  flagellated sperm fertilize the nonmotile egg
Sporophyte  2n (diploid) generation
Gametophyte  n (haploid) generation
Isomorphic  gametophytes and sporophytes look alike
Heteromorphic  gametophytes and sporophytes are
structurally different 

7. Compare the life cycles of plasmodial and
cellular slime molds and describe the major
differences between them.
Plasmodial Slime Mold Cellular Slime Mold
Multinucleated mass Solitary haploid cells
Diploid nuclei Cells will aggregate when
When stressed will form food supply is low
sexual reproductive Fruiting bodies (sporangia)
structures called sporangia function in asexual
 reproduction 

8. Provide evidence that the oomycetes are
not closely related to true fungi.
Have coenocytic (multinucleated) hyphae
(branching filaments) that are analogous to
fungal hyphae
Cell walls are made of cellulose rather than
the chitin in true fungi
Have biflagellated cells  fungi lack
flagellated cells 

9. Give examples of oomycetes and describe their
economic importance.
• Water molds  grow on injured tissue but
also will grow on the skin and gills of fish
• White rusts
• Downy mildews
- both of these are parasitic on terrestrial
plants – act as pathogens 

10.  “sea lettuce”
 attached to rocks in the middle to low
intertidal zone
 live primarily in marine environments
 Multicellular green algae

11. MITOSIS
MEIOSIS
E
MITOSIS
GAMETES
Fertilization

12. -Involves alternation of generations
-Ulva species are isomorphic
-They alternate between gametophytic and
sporophytic life stages with similar morphologies
-gametophytes are haploid and the sporophytes
are diploid

13. -sporophytes produce quadriflagellate
haploid spores through meiosis
-gametophytes produce biflagellate
haploid gametes through mitosis