Phycology course including different algal groups

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

2. Classification of
Chlorophyta (green algae)
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3. Order: Volvocales
General features
1. Forms are unicellular or colonies.
2. Forms are motile.
3. Most species are freshwater
Family: Chlamydomondaceae
e.g. Chlamydomonas
Habit: motile Unicellular
Asexual Reproduction;
Zoospores & Aplanospores
Sexual Reproduction:
isogamy & anisogamy
Life cycle: Haplontic
-
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4. Life cycle of Chlamydomonas
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5. Family Volvocaceae
Pandorina
Habit: motile colony
Asexual Reproduction: Daughter colonies
Sexual reproduction: Anisogamy
Life cycle: Haplontic
Eudorina
Habit: motile colony
Asexual reproduction: daughter colonies -
Sexual Reproduction: Anisogamy
Life Cycle: Haplontic
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6. Volvox
Habit: motile colony
Asexual Reproduction: daughter colonies
Sexual reproduction: Advanced Oogamy
Life cycle: haplontic
- Volvox contains different kinds of cells:
1. Vegetative cells (Movement & photosynthesis)
2. Asexual cells (Asexual Reproduction).
3. Sexual cells (Sexual reproduction).
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7. Order Chlorococcales
General features
The forms are unicellular or colonies
- the forms are nonmotile
-Family Chlorellaceae
Chlorella
Habit: nonmotile unicellular
Asexual reproduction: Autospores
Sexual reproduction: absent
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8. Life cycle of Chlorella
- During the formation of autospores, 4 important
phases in the life cycle of chlorella are recognized:
1. Growth phase
- the autospores increased in the size.
2. Early ripening phase
- The cells prepare themselves for undergoing cell
division
3. Post ripening phase
-the cells divide twice in light or darkness
4. Division phase
The wall of parent cell is ruptured and the autospores
liberate
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9. Life cycle of Chlorella
Da = Dark active cells
Dn = Dark nascent cells
D-L= dark to light transitional cells
L1= large cells with DNA
L2 = Dividing cells
L3 = Tetranucleate cells
L4=
Tetranucleate autospore
mother cells
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10. Family Hydrodictyaceae
Pediastrum
Habit: nonmotile colony
Asexual reproduction: zoospores
Sexual reproduction: isogamy, and the formation of
Polyhedron
Life cycle: haplontic
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11. Sexual reproduction in Pediastrum
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12. Hydrodictyon
Habit: nonmotile colony
Asexual reproduction: zoospores
Sexual reproduction: isogamy, and the formation of
Polyhedron
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13. Sexual reproduction in Hydrodictyon
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14. Polyhedron
This is a polyhedral structure formed during
the sexual reproduction by the metamorphism
of a zoospore.-
Metamorphism
The arrangement of zoospores in the form of a parent
alga.
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