Phycology course for undergraduate students of Biology groups

1. Phycology(BMIC 362)
Prof Dr. Zakaria A.
Mohamed

2. Classification of
Chlorophyta (green algae)
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3. Class: Ulvophyceae
Order: Ulotrichales
Family : Ulotrichaceae
Ulothrix
Habit: simple filament with rhizoid
Veg. Rep: Fragmentation
Asexual reproduction:
zoospores (biflagellate & quadriflagellate) ,
,aplanospores, Akinetes
Sexual reproduction: Isogamy
Life Cycle: Haplontic
• Chloroplasts are collar
• -shaped & parietal
-
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4. Life cycle in Ulothrix
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5. Order : Ulvales
Family: Ulvaceae, Ulva
Habit: Foliaceous (parencymatous)
Asexual reproduction: quadriflagellate zoospores
Sexual reproduction; Isogamy &Anisogamy
Vegetative reproduction: fragmentation
Life cycle: isomorphic life cycle
•Ulva fronds are composed of two layers of cells, Each cell
has a large cup-shaped chloroplast, pyrenoid and nucleus
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7. Order: Cladophorales
Family :Cladophoraceae
Cladophora
Habit: Branched filament
Asexual rep: zoospores,
akinetes
Vegetative rep. Fragmentation
Sexual rep.: Isogamy
Life cycle: Isomorphic
Chloroplasts: reticulate & Cells with many nucleii
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Nuclei

8. Order :Caulerpales
Family: Codiaceae
Codium
Habit: Siphonaceous form
Asexual Reproduction: absent
Sexual Reproduction: Isogamy
Life cycle: Dipontic
The thallus consists of a semi-rhizome part and shoots
with central medulla that give rise to the utricles (branhlets
The utricles contain central vacuole, peripheral
cytoplasm, many nuclei, discoid chloroplast.
The gametangia are formed on these utricles.
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9. Codium life cycle
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10. Class: Charophyceae
This is the line of algal evolution that led to the development of land plants
Order : Conjugales
Family : Zygnemataceae
Zygnema - Stellate chloroplast
Spirogyra – Spiral chloroplast
Habit: Unbranched filament
Vegetative Rep: Fragmentation
Asexual Rep: Aplanospores
Akinetes, azygospores.
Sexual Rep: Scalariform
Lateral conjugations
Life cycle: Haplanotic
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11. ‫ا‬ ‫ر‬
‫وجي‬ ‫ر‬
‫االسبي‬ ‫حياة‬ ‫دورة‬
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12. Azygospores (parthenospores)
Gametes that failed to fuse during sexual reproduction,
and they function as spores germinating to a new alga.
Zygospores
zoospores resulted from the zygote division
Scalariform conjugation
the fusion between each two opposed cells in two
different filaments.
Lateral conjugation
The fusion between each two lateral cells in the same
filament.
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14. Family Desmidiaceae
Cosmarium
Closterium
Habit: Unicellular
Asexual rep: Cell division,
azygospores
Sexual rep: Isogamy
Life cycle: Haplontic
The alga consists of two semicells
connected by a narrow region
Called isthmus, with a deep median
Constriction called sinus
-
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15. Cell division
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16. Sexual Reproduction
• The contents of cells
behave as gametes
• Gametes fuse forming
Zygote
The 2n zygote nucleus
divides meiotically 4 1n nucleii
Only two nucleii are functional
Zygospore chloroplast divides
to 2 daughter chloroplasts
-Each chloroplast with one
-nucleus forms a new alga
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