Unit 6 – Lecture 3
Algae – an Introduction
 Alga – plant like protist – plural, algae
 unicellular or multicellular
 major producer of world’s oxygen
 sexual or asexual reproduction or both
 alternation of generations
 autotrophic – photosynthetic
Algae – An introduction
 Six Phyla of Algae
 Euglenophyta
 Bacilliarophyta
 Dinoflagellata
 Chlorophyta
 Rhodophyta
 Phaeophyta
Discuss
 All of these end in “phyta”
 phyte, phyto or phyta refer to
being ____________ like or being a ______________.
Euglenophyta
 the Euglenoids
 plant-like photo-
synthesis, but animal-like
movement w/ flagellum
 unicellular
 autotroph and heterotroph
 asexual reproduction
 pellicle & red eye-spot
(eyespot)
Bacillarophyta
 Diatoms
 unicellular
 autotrophic – photosynthetic
 chlorophyll & carotenoids
 asexual or sexual reproduction
 silica shells, diverse shapes
 food storage as OIL not starch
Dinoflagellata
 Dinoflagellates
 have 2 (“di”) flagella
 unicellular
 autotrophic –
photosynthetic
 chlorophyll &
carotenoids
Dinoflagellata
 asexual reproduction [or weird fusion…]
 thick cellulose plates
 bioluminescence
 can be harmful
Dinoflagellata
 red tide
Discuss
 Which phylum of algae…
 have shells made of glass?
 are responsible for the harmful red tides?
 are both auto- and hetero- trophic?
 Which type(s) of algae are phytoplankton, and what
great benefit do phytoplankton serve?
Chlorophyta
 Green Algae – most diverse
 unicellular, multicellular, or colonial
 most in water but
all need moist
place to survive…
Chlorophyta
…a moist place like a
SLOTH!
[only 2 – 4 meters per minute ]
Chlorophyta
 can have flagella
 alternation of generations
Alternation of Generations
 type of reproduction
utilizing asexual
& sexual means
Alternation of Generations
 offspring generations
alternate between being
haploid [1n] in one
generation to being
diploid [2n] the next.
Alternation of Generations
 Sporophyte [2n]
produces spores [1n]
through meiosis
Alternation of Generations
 Spores [1n] produce
gametophytes [1n]
through
mitosis
Alternation of Generations
 Gametophyte [1n]
produces gametes [1n]
through mitosis
Alternation of Generations
 Gametes [1n] fuse
in fertilization to
produce zygote [2n]
Alternation of Generations
 Zygote [2n] grows to
become embryo [2n]
Alternation of Generations
 Embryo [2n] grows
to become
sporophyte [2n]…
 etc.
Discuss – What You Need to Know
About Alternation of Generations
 type of reproduction utilizing
_______________ & _______________ means
 offspring generations alternate between being
_______________ [1n] in one generation to being
_______________ [2n] the next.
 gametophytes [1n] make _______________ [1n]
through mitosis
 sporophytes [2n] make _______________ [1n]
through meiosis
Other Phyla
 Rhodophyta – sea weeds, red algae
Other Phyla
 Phaeophyta – brown algae, kelp
 most in salt water
 have air bladders to keep them afloat
Discuss
 What is the most diverse
group of plant-like protists?
Fungus-Like Protists
 Slime Molds, Water Molds, & Downy Mildews
 unicellular to colonial
 heterotrophic – saphrophytic
 have cell walls
 live in moist places
 all have movement at some
point in their life cycle to get to food
Fungus-Like Protists
 “mycota” / “mycete” – fungus or fungus-like
 examples
 myxomycota – plasmodial slime molds

form a plasmodium
 no cell wall
 no membranes
Fungus-Like Protists
 “mycota” / “mycete” – fungus or fungus-like
 examples
 myxomycota – plasmodial slime molds

form a plasmodium
 many nuclei –
cells merge together
into a large mass
 amoeboid movement
 reproduce with spores
Fungus-Like Protists
 “mycota” / “mycete” – fungus or fungus-like
 examples
 acrasiomycota – cellular slime molds



come together to reproduce
only when food is scarce –
otherwise, independent
has cell membrane
haploid during entire life cycle
Fungus-Like Protists
 “mycota” / “mycete” – fungus or fungus-like
 examples
 oomycota – water
molds & downy
mildews
 produce flagellated
reproductive cells
 very large and
diverse group
Discuss
 What word refers to…
 the color red?
 the color green?
 the color brown?
 plant or plant-like?
 fungus or fungus-like?
Homework
 complete the
Euglena Reading & Coloring w/s
 [and finish the webquest if you
haven’t done so… it’s due tomorrow]