By Danielle & Samantha
Phylum Phaeophyta
(Brown Algae)
Basic Information
 1500 Species
 Thallic structure
 Have chlorophylls A & C
 Fucoxanthin, a carotenoid, is the
pigment which gives them their
characteristic brown to olive-green
color
Basic Information
 Have 2 Flagella in reproductive cells only
 Store Laminarin and Mannitol, rather than starch
 Some have plasmodesmata
 Cell wall is made of cellulose in a matrix of
mucilaginous algin
Habitat
 Mostly Marine
 Found in Temperate,
Northern, and Polar Oceans
 Flourish in colder waters
 Occupy rocky shorelines and
sloping shores just off the
coast
Unifying Characteristics
 Almost an entirely marine phylum
 Basic form is a thallus
 Fucoxanthin pigment
Unique Features & Applications
 Size from small filamentous epiphytes to very
complex kelp which can reach heights of 100 meters
 Kelp forest can last up to 10 years depending on
location and exposure to waves
Unique Features & Applications
 Source of agar(from cell walls): used as a thickening
agent in Petri dishes
 Also used as a source of thickening agent and
stabilizer in the food, cosmetic, pharmaceutical, and
industrial industries
 Harvested as a food source
 Keystone species in kelp forests providing a food
source and habitat for other species
Life cycle
 Most have a
Sporic
Meiotic Life
cycle with
Alteration
of
Generation
Life cycle
 Some, such
as Fucus,
have a
Gametic
Meiotic
Life cycle
Phylum Rhodophyta
(Red Algae)
Basic Information
 6000 Species
 Phycobilosomes are responsible for the red color: red
antenae proteins associated with the photo systems
 Have chlorophyl A and carotenoids
Basic Information
 Use floridean starch in food storage
 They do not have flagella or centrioles
 Cell walls are made of cellulose embedded in a matrix
with microfibrils
 Some can also incorporate calcium carbonate into
their cell walls
Basic Information
 In terms of structure, red algae have a wide range of
forms, including string-like, tube-like, filamentous
and flat sheets
 Unlike green algae, red algae seldom are important in
rocky shore or reef communities; they prefer deeper
waters.
Habitat
 Mostly Marine and Tropical
 Have about 100 freshwater species
Unifying Characteristics
 No flagella or centrioles
 Lack motile gametes
 Some species of red algae can survive at 200 meters
below sea level
 The different pigments allow them to grow at far
greater depths than the green and brown algae by
broadening the spectrum of sunlight which they can
absorb and use in photosynthesis
 the red color is nowhere near uniform: some species
are purple, mauve, orange, or even yellow
Unique Features & Applications
 Red algae is promoted by supplements distributors to
treat the herpes simplex virus
 Red algae are eaten by humans. Two examples are
nori, which is used in sushi, and Irish moss, which can
be made into pudding
Life cycle
 Can reproduce
asexually, but
most often will
reproduce
sexually
through a
Sporic Meiotic
life cycle with 3
generations
Phylum Chlorophyta
(Green Algae)
Basic Information
 17,000 Species
 Get their color from chlorophylls A & B.
 Also contain carotenoids
 Store starch in plastids as food reserve
 Some have cellulose in cell walls, others have
glycoproteins and polysaccharides
 Some have plasmodesmata
 Can have almost any number of flagella
Habitat
 Mostly Aquatic, fresh water or
marine
 Can also live on rocks, soil,
trees, snow, or in the air
 Many live in symbiotic
relationships
Unifying Characteristics
 All contain chlorophylls A & B
 Main source of food storage is starch
 These unifying characteristics are important when
considering their relationship to true plants
Unique Features & Applications
 Nowadays used in the treatment of waste water and
controlling pollution
 They are also being considered for producing fuel or
bio fuel
 It was said that the growth in species of this algae is
so fast that text books are out of date almost as soon
as their printed
Unique Features & Applications
 Lives in a symbiotic relationship with sloth fur. The
fur provides protection and absorbs water readily,
while the algae provides nutrients by diffusion
through the skin of the sloth
 Can live in a symbiotic relationship with fungi as
lichens
Life cycle
 Most have
Zygotic
Meiotic life
cycles
Life cycle
 Some have
Sporic Meiotic
life cycles with
alternation of
generation
Class Chlorophyceae
Class Chlorophyceae
 Mostly fresh water
 Can, but don’t always, have flagella
 Unicellular, or colonial
 Can form filaments or thallic sheets
 Some have plasmodesmata
 Have phycoplasts: a mititic structure similar to a cell
plate froming with some pinching in of cell walls
Class Ulvophyceae
 Mostly marine.
 Filamentous or thallic
 Some members have sporic
life cycle
 Used as a food source
Class Charophyceae
Class Charophyceae
 Precursor to true terrestrial plants
 Can be fresh water or terrestrial
 Have a zygotic meiotic life cycle
 Have apical meristems
 Secrete chemical precursors to make cuticle
 Sporopollenin encases the zygote: precursor to
embry0phytes
Class Charophyceae:
Chara & Coleochaete
 Make phragmoplasts: cell plate
formed in mitosis
 Oogamous: large female gamete
is non-motile, small motile male
gamete travels to it for
fertilization
 Closest species to true terrestrial
plants