List the characteristics of protists. List the characteristics of protists.

They are the earliest eukaryotes They are the earliest eukaryotes showed showed up a billion years before the othersup a billion years before the others

Age Age 2.1 billion years 2.1 billion yearsThere are 60,000 living speciesThere are 60,000 living speciesExist as unicellular, colonial, and Exist as unicellular, colonial, and multicellularmulticellular

Aerobic, cilia & flagella, asexual or sexualAerobic, cilia & flagella, asexual or sexualBottom line: a VERY diverse group Bottom line: a VERY diverse group

Explain what is meant by the statement Explain what is meant by the statement that the Kingdom Protista is a that the Kingdom Protista is a polyphyletic group.polyphyletic group.

Polyphyletic = ancestry from several Polyphyletic = ancestry from several possible sources or directionspossible sources or directions

Example:Example:Protists are Protists are animal-like animal-like

plant-likeplant-like fungus-like fungus-like

List five candidate kingdoms of List five candidate kingdoms of protists and describe a major protists and describe a major feature of each.feature of each.

1.1. Archaezoa Archaezoa lack mitochondria lack mitochondria2.2. Euglenozoa Euglenozoa are both autotrophic and are both autotrophic and

heterotrophic flagellatesheterotrophic flagellates3.3. Alveolata Alveolata have subsurface cavities have subsurface cavities

(alveoli)(alveoli)4.4. Stramenopila Stramenopila diatoms, golden brown diatoms, golden brown

algae, and water moldsalgae, and water molds5.5. Rhodophyta Rhodophyta red algae; lack flagella red algae; lack flagella

Life Cycle overviewLife Cycle overview

Sporophyte Sporophyte generally the adult form of generally the adult form of an organism; exists as a diploid (2n); an organism; exists as a diploid (2n); makes spores (ex: humans)makes spores (ex: humans)

Gametophyte Gametophyte generally an intermediate generally an intermediate step before fertilization; exists as a step before fertilization; exists as a haploid (n); makes gametes (ex: sperm & haploid (n); makes gametes (ex: sperm & eggs) eggs)

Outline the life cycles of Outline the life cycles of Chlamydomonas, Ulva, Chlamydomonas, Ulva, and and LaminariaLaminaria and indicate whether the and indicate whether the stages are haploid or diploid.stages are haploid or diploid.

1.1. ChlamydomonasChlamydomonas at maturity it is a single at maturity it is a single haploid cellhaploid cell- - asexual at first, then sexual only if stressed, asexual at first, then sexual only if stressed, creating a diploid zygotecreating a diploid zygote

2. Ulva2. Ulva diploid sporophyte and haploid diploid sporophyte and haploid gametophytegametophyte

3. Laminaria3. Laminaria sporophyte (2n) with sporangia sporophyte (2n) with sporangia makes zoospores (n) which make gametes (n) makes zoospores (n) which make gametes (n) and then fertilization to get diploid sporophyte and then fertilization to get diploid sporophyte again again

Distinguish between isogamy and Distinguish between isogamy and oogamy; sporophyte and oogamy; sporophyte and gametophyte; and isomorphic and gametophyte; and isomorphic and heteromorphic generations.heteromorphic generations.

Isogamy Isogamy when gametes are morphologically when gametes are morphologically indistinguishableindistinguishable

Oogamy Oogamy flagellated sperm fertilize the flagellated sperm fertilize the nonmotile eggnonmotile egg

Sporophyte Sporophyte 2n (diploid) generation 2n (diploid) generationGametophyte Gametophyte n (haploid) generation n (haploid) generationIsomorphic Isomorphic gametophytes and sporophytes look gametophytes and sporophytes look

alikealikeHeteromorphic Heteromorphic gametophytes and sporophytes gametophytes and sporophytes

are structurally differentare structurally different

Compare the life cycles of plasmodial and Compare the life cycles of plasmodial and cellular slime molds and describe the cellular slime molds and describe the major differences between them.major differences between them.

Plasmodial Slime MoldPlasmodial Slime MoldMultinucleated massMultinucleated massDiploid nucleiDiploid nucleiWhen stressed will form When stressed will form

sexual reproductive sexual reproductive structures called structures called sporangia sporangia

Cellular Slime MoldCellular Slime MoldSolitary haploid cellsSolitary haploid cellsCells will aggregate Cells will aggregate

when food supply is when food supply is lowlow

Fruiting bodies Fruiting bodies (sporangia) function in (sporangia) function in asexual reproduction asexual reproduction

Provide evidence that the Provide evidence that the oomycetes are not closely related oomycetes are not closely related to true fungi.to true fungi.

Have coenocytic (multinucleated) Have coenocytic (multinucleated) hyphae (branching filaments) that hyphae (branching filaments) that are analogous to fungal hyphaeare analogous to fungal hyphae

Cell walls are made of cellulose rather Cell walls are made of cellulose rather than the chitin in true fungithan the chitin in true fungi

Have biflagellated cells Have biflagellated cells fungi lack fungi lack flagellated cells flagellated cells

Give examples of oomycetes and Give examples of oomycetes and describe their economic importance. describe their economic importance.

1.1. Water molds Water molds grow on injured tissue grow on injured tissue but also will grow on the skin and gills but also will grow on the skin and gills of fishof fish

2.2. White rusts White rusts 3.3. Downy mildewsDowny mildews

- both of these are parasitic on - both of these are parasitic on terrestrial plants – act as pathogens terrestrial plants – act as pathogens

““seasea lettucelettuce””

live primarily in marine environments live primarily in marine environments

attached to rocks in the middle to low attached to rocks in the middle to low intertidal zone intertidal zone

Multicellular green algaeMulticellular green algae

MITOSIS

MITOSIS

MEIOSIS

Fertilization

GAMETES

E

-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

-sporophytes produce quadriflagellate haploid spores through meiosis

-gametophytes produce biflagellate haploid gametes through mitosis