Phycology course including different algal groups

1. Phycology(BMIC 262)
Prof Dr. Zakaria A.
Mohamed

2. Phaeophyta
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3.  They are macroalgae found almost exclusively in
the marine habitat
 Contain Chl. A and fucoxanthin (brown) pigments
 Cell wall - cellulose and alginic acid
 Storage material: Laminarin
 The chloroplasts have two membranes of
chloroplast E.R continuous with the outer
membrane of the nuclear envelope
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4. Order Fucales
Fucus & Sargassum
Habit: Parenchymatous
Thallus: holdfast, stipe, blade,
airbladders, fronds, receptacles
Veg. rep.: Fragmentation
Asexual rep.: absent
Sexual rep. Oogamy
Gametes are formed in
conceptacles located on the
receptacles (the reproductive
branches). 4
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5. Life cycle: Diplontic
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6. Medical and ecological significance of brown algae
 Food for herbivorous fish and shellfish, and human
 Algin -a stabilizer and emulsifier in making dairy
products. , a thickener in pharmaceutical and
chemical industries, such as making toothpaste,
shampoo.
 In textiles, alginates are used to thicken fiber-reactive
dye pastes
 Alginates - dental impressions of teeth.
 The seaweed can also be used for sushi.
 Fucoidans which inhibits lipid accumulation and
therefore can be useful for the prevention or
treatment of obesity due to its stimulatory lipolysis.
 Fucoidans from the brown alga Sargassum exhibits
anticancer activity
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7. Rhodophyta- Red algae
 Most red algae are marine macroalgae
 No flgellated forms
 Main pigments: Chl.a and Phycoerythrin (red)
 Storage material: Floridian starch
 Cell wall: cellulose,
 Like Cyanobacteria, chloroplast with one thylakoid
per band (unstacked thyllakoids) and no
chloroplast E.R.
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8. Asexual rep: Tetraspores
Sexual Rep: oogamy and formation of carpospores.
Life cycle in Polysiphonia has three stages (triphasic
isomorphic gametophyte (1n) and sporophyte (2N)
generations are separated by the carposporophyte (2N).
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10. Medical and ecological significance of red algae
 Primary producers, used as food and medicines for
centuries
 They produce agar, carrageenans, and alginates used in
numerous food, pharmaceutical, cosmetic, and
industrial applications.
 Carrageenan is used for stabilizing chocolate, milk, egg
nog, ice cream, sherbets, instant puddings, frostings,
creamed soups, etc.
 Agar is used in bacteriology and mycology as a
stiffening agent in growth media.
 Agar is used as a stabilizer for emulsions, and as a
constituent of cosmetic skin preparations, ointments,
and lotions.
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11. A very important group of red algae is the coralline
algae, are used in bone-replacement therapies.
Coralline algae were used in ancient times as
vermifuges (antiparasitic)
sulfated polysaccharides inhibit both the DNA and
RNA of viral infections and may operate both outside
and within our infected cells.
Red algae contain bromophenols, which have Cellular
Antioxidant Activity.
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12. Euglenophyta
General characteristics
 aniEuglena is autotrophic and heterotrophic both
 Live in mal pollution or decaying organic matter.
 naked (without cell wall) unicellular flagellates,
 Contain chlorophylls a and b, and carotenids
 one membrane of chloroplast endoplasmic reticulum.
 have flagella, and paramylon or chrysolaminarin as the
storage product in the cytoplasm.
 The nucleus is of the mesokaryotic type, having
chromosomes that are permanently condensed during the
mitotic cycle, a nucleolus (endosome) that does not
disperse during nuclear division, no microtubules from
chromosomes to pole spindles.
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13. Example : Euglena
Phacus
Habit: motile Unicellular
Asexual reproduction:
- cell division
- Thick walled resting cysts ( Pamelloid
stage ).
Sexual rep: absent
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