Transcript Plant-Like” Protists: - Emerald Meadow Stables

“Plant-Like” Protists:
Multicellular Algae
Multicellular Algae
• AKA “Seaweed”
• Algae lack an internal system of tubes to move
water and material from one part of the plant to
another
– Seaweeds
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are large, multicellular marine algae,
grow on or near rocky shores,
are most closely related to unicellular algae, and
are often edible.
Multicellular Algae – Green, Red,
and Brown Algae
• Most are multicellular
• Can reach 60 meters in length, cells contain cell
walls, contain chlorophyll a
– Seaweeds are classified into three different
groups, based partly on the types of pigments
present in their chloroplasts:
1. green algae,
2. red algae, and
3. brown algae (including kelp).
Phylum Chlorophyta – Green Algae
• Chlorophyll a and b
• Store food as starch, found in moist areas and
fresh water
• Some marine
• Some live as single cells, some form colonies,
and some are multicellular
• Sexual and asexual reproduction
• May be ancestor to land plants
• Vulvox (colonial algae), spirogyra, ulva
Green Algae Examples
Vulvox
Spirogyra
Ulva
Phylum Rhodophyta – Red Algae
• Contain chlorophyll a and reddish accessory
pigments called phycobilins – good for
absorbing blue light and can live deeper than
other algae
• Store food as special starches
• Found from far North to the tropics to a depth
of 170 meters
• Chondrus crispus, Irish moss – common red
algae
Red Algae Examples
Chondrus crispus
Antithamnion
plumula
Phylum Phaeophyta – Brown Algae
• Chlorophyll a and c as well as brown
pigment called fucoxanthin
• Store food as special starches and oils
• Important marine algae found in shallow
temperate regions
• Largest, and most complex of the algae
• Kelp, sargassum, fucus
Fucus Anatomy
Brown Algae Examples
Fucus
Kelp
Reproduction in Algae
• Alternation of generations – alternate
generations are sexual and asexual –
sexual reproduction involves the
production of gametes and asexual
production involves haploid cells called
zoospores (switch back and forth)
Reproduction in Ulva – a Green
Algae
• Diploid algae called the sporophyte,
haploid algae called gametophyte
• Two different gametophytes – male and
female – having two types of
gametophytes is called heterogamy
Ulva Life Cycle
MITOSIS
Zygote
Gametes
fuse
MEIOSIS
Sporophyte
Spores
FERTILIZATION
Gametes
Female
gametophyte
Diploid
Haploid
MITOSIS
Male
gametophyte
Reproduction in Fucus – a Brown
Algae
• Alternation of generations and heterogamy
• Female gamete – egg
• Male gamete - sperm
Human Uses of Algae
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Drugs
Sushi
Ice cream
Salad dressing
Pudding
Candy bars
Eggnog
Toothpaste
Deoderant
Agar……..