مي عز الدين
04-05-2022 - 10:48 am
بسم الله الرحمن الرحيم بعد السلام والتحية لكل الفراشات الحلويين
بدي منكم هالخدمة الصغيرة و ياريت ما تتخلو عني فيها
الدكتور في الجامعة طلب منا بحث عن ( اهمية الطحالب البيئية و الاقتصادية وفوائدها العلمية )
ارجو من اي فراشة يكون عندها موقع يفيدني تكتبه ويلي عندها بحث تعطيني شوية افكار منه
او اي مساعدة باي شكل من الاشكال- لاني مليت وانا ادور و ما كنت اجد شي
و اخيرا اتمنى لكم التوفيق ولكم مني احسن الدعاء
.
الطحالب.. تلتهم مخلفات الصناعة
http://www.islamonline.net/Arabic/Sc...rticle01.SHTML
هذه صفحة عن الطحالب الخضراء و الزرقاء و البنية و فوائدها بالإنجليزي
http://library.thinkquest.org/27115/...ae_bottom.html
Today, the algae have taken on added economic importance (as food, for commercial products, water contamination, toxin-production, sewage oxidation, etc.). Further, with the development of refined culture techniques and the electron microscope, physiologists and cytologists are employing algae more than ever as subjects of study for fundamental scientific information. The geneticist, limnologist, paleontologist, and plant evolutionist find investigations of algae to be both necessary and highly rewarding. One needs but to consider the current flood of literature dealing with the many aspects of algae (taxonomic, physiological, morphological, ontological) to gain an appreciation of the place that algae hold in human and scientific affairs.
هذه معلومات أخرى و بما أنك في الجامعة أكيد المعلومات الإنجليزي بتفيدك
Algae
Live in diverse habitat, mostly aquatic
• Green algae
• Brown algae
• Red algae
Protists? Unlike plants, lack ovaries
Unicellular: to gigantic multicellular organisms
Some are coenocytes: no cross walls between cells
Green algae
Division: Chlorophyta, 7,500 species
• Ancestors of plants
- Zygote are retained in gametophytes
- Produce flavonoids
Chlamydomonas
• Unicellular
• Large chloroplast
• Reproduce a***ually by mitosis
• Reproduce ***ually by meiosis
Volvox: Colonial Green Algae
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Spirogyra
• Spiral chloroplast
• A***ual reproduction: restricted to filaments
• ***ual reproduction via conjugation
• Filamentous green algae
• Unique characteristics
• Antheridia and Oogonia are ***ual organs
• Which are surrounded by sterile jacket
Chara
Oedogonium
Spirogyra, a green algae
Members of this smallest group have
a complex multiflagellate crown on
their
swimming
spores.
All are
filamentous, oogamous, and have
net-like chloroplasts
Oogamous: Characterized by or having small motile male gametes and
large nonmotile female gametes
Oogonium and antheridium of
Chara (Charophyta), l.s.
Chara (Charophyta) with oogonia and antheridia
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Red snow, seen here near Beartooth summit in
Wyoming, is caused by Chlamydomonas, a unicellular
green alga (Chlorophyta)
Ectocarpus, the best known of filamentous
brown algae
Brown Algae
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Fucus (Phaeophyta) growing
on intertidal rocks near Bar
Harbor, Maine
Red Algae: Rhodophyta
- Microscopic filamentous
- Macroscopic leafy branch
Phycoerythrin, a red phycobilin
- absorbs light in the blue spectrum
Coralline algae: Cell walls impregnated with calcium
and magnesium carbonate
Red Algae
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great Barrier Reef
Florida Red Tide Bloom of
Gymnodinium breve
California Noctiluca
Bloom
• Chrysophyta (largest algal division)
• Lack flagella but some are motile
• Unicellular with symmetrical body
• Primary producers for filter feeders
• Reproduce
• A***ual reproduction by mitosis
• ***ual reproduction
________________________________________
Other divisions of algae
•
Flagellated unicellular organisms
1. euglenoids
2. dinoflagellates
3. cryptomonads
Traditionally studied by both zoologists
and botanists
Importance of Algae in Ecosystems
Planktons
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DE is composed of finely milled fossilized shells of
minuscule organisms called diatoms. The microscopically
fine, sharp edges desiccate the insects' exoskeleton upon
contact and the pests dehydrate and die within hours. The
insects also die when they eat the dust
Diatomaceous Earth
Chondrus crispus Stackhouse
A source of carrageenan (a sulphated polysaccharide),
and used to make soups, jellies, etc., and in Ireland as a
remedy for respiratory disorders. The colloquial English
name "Carrageen" was introduced in Ireland about 1840
Protist Specimens for the laboratory
• Euplotes
• Difflugia
•Centropyxis
• Blepharisma
• Paramecium bursaria
• Cyanophora paradoxa
• Amoeba proteus
• Pandarena
• Euglena sp
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Euplotes, another very amazing creature to watch as it uses its larger cilia
beneath its body to position itself for feeding and movement
Taxonomic Characterization: The genus Euplotes is characterized by rows of fused cilia called cir i running along the ventral
(bottom) surface. Cirri are used for swimming and also to "walk" along a substrate. E. iliffei is a medium sized marine Euplotes
with an ellipsoid body shape. Most other Euplotes species inhabit freshwater. Dorsal interkinetal argentophilic reticulum is of the
multiple to complex type with a tendency toward 4 interkinetal polygonal areas (Hill et al., 1986). Like other members of the group
of Euplotes that have a frontoventral cir i in pattern I, the VI/2 cir us is missing. E. iliffei also has a very pronounced notch in the
upper border of the dorsal surface.
Ecological Clas ification: Stygobitic
Size: Total body length 90-115 microns (average 101 microns); bodywidth 70-100 microns (average 85 microns).
Number of Species in Genus: 52, of which only one (E. ilif ei) is anchialine.
Species Range: Known only from Wonderland Cave, Hamilton Parish, Bermuda (Hill et al., 1986).
Closest Related Species: Fifteen species of Euplotes, including 9 marine, 2 euryhaline and 4 freshwater species, belong to the type
one frontoventral cirrotype pattern where cirrus VI/2 is absent (Hill et al., 1986). E. iliffei s similar to E. indentatus described from
an intertidal pool in Nas au, Bahamas.
Habitat: Anchialine limestone caves
Ecology: Along with many other protozoa, E. iliffei nhabits an anchialine lake in Wonderland Cave, Hamilton Parish, Bermuda.
This cave is situated 420 m inland from Castle Harbour, the nearest water body. Specimens were col ected from surface waters
of the main cave lake using small protozoan traps baited with tuna fish. At he time of collection, water temperature
ranged from 20.2 to 21.2oC and surface salinity was 12 ppt.
EvolutionaryOrigins: Probably derived from a marine Euplotes.
Conservation Status: Restricted to a single anchialine cave.
The Difflugia is a smal amoeba and belongs to the Phyl um Sarcodina.
It lives in a rather large chitinous "test" (shel ). The shel is usual y covered completely with sand grains. The Difflugia is
from 200-250 microns long.
Pseudopods extend out from the shel and are used for locomotion.
This shel ed rhizopod feeds mainly on Spirogyria (a green algae)
Centropyxis aculeata
This species is found in great numbers in both the Cobalt area and Lake Sentani. This species can live just about
anywhere within a lake, however it prefers the warmer waters above the thermocline. This arcellacean can vary in its
morphology ranging from spiny to spineless. The latter doesn't mean that it's a pushover, though.
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Blepharisma is a heterotrich ciliate and a microphagus filter feeder. It usually eats bacteria found in decomposing
vegetation by drawing them into its vortex of membranelles that surround its buccal cavity (mouth). The food is then
passed through the cytostome and enclosed in food vacuoles which are distended to the posterior end of the cell
Paramecia and Blepharisma are from the same family of ciliates and about the same size. However,
Blepharisma moves more slowly than paramecia and are distinguished by their rose colored pigment
Genus: Cigar- or foot-shaped; a single macronucleus and 1 to several vesicular or compact microuclei
(Kudo, 1966).
Species: 100-150 µm long, 50-60 µm wide; foot-shaped; green with symbiontic Chlorella; a compact
micronucleus; a macronucleus; two contractile vacuoles (Kudo, 1966). Ovoid, anterior transversely
truncated, posterior rounded; 80-150 µm long; oral groove wide; cytoplasm filled with green
zoochlorellae; two contractile vacuoles; a single ovoid macronucleus and a micronucleus; caudal cilia
present (Carey, 1992).
Paramecium bursaria cells
showing conjugation
Cyanophora paradoxa
This single-celled eukaryotic organism has a photosynthetic organelle, the cyanelle, surrounded by a
rudimentary peptidoglycan wall which betrays its bacterial origin. But does it have the same evolutionary
roots as higher plants?
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Amoeba proteus
One of the most enigmatic microscopic life forms is
the amoeba. Almost everyone knows what amoeba
are, which is quite remarkable since they are not that
common. Microorganisms like rotifers are much
easier to find but drop the name 'rotifer' in a
conversation and most people will not know what
you are talking about. But mention the word 'amoeba'
and people will say: 'Yes, you mean those critters
that can take any shape they like!'
They are legendary as the ultimate 'shape shifters'.
Despite their good publicity they remain much of a
mystery. It is even quite hard to find them. They are
easily overlooked since they are so transparent or not
recognized as living organisms since they often
resemble decaying organic remains.
Some time ago I was asked if I could produce a
series of images of microorganisms such as the
Hydra, Paramecium and an Amoeba. I had to confess
that I had never photographed an amoeba. So I tried
to find out how to catch them. I read about the
following method: Hold a jar upside down under
water until it is situated just above the bottom of a
pond. Then slowly tilt the jar to let the air escape.
This way the top layer of the soil on the bot om of
the pond wil be sucked inside the jar. Many amoebas
inhabit this top layer of decaying organic material.
Pandorina morum
A vegegative motile colony of Pandorina, usuually a clump of 8 or 16 cells held in a
common envelope of mucilage. Each cell has two flagella.
Euglena sp
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Bosmina with its characteristic 'snout': in fact they are the two
elongated first antennae. The mouth at the beginning of the gut is
clearly visible in this image
Water fleas belong to the Crustacea, a large group of 'jointed limbed' animals, most of which live in water. Water fleas are
placed in the order Cladocera and are probably called 'fleas' because they move through the water by a sort of hopping. Water
fleas are very common in fresh water, in Britain you can find about 80 different species, in The Netherlands about a 100
species. Many of them are rare. For most people, water fleas are all similar, but when we look more closely, big differences
will be found in morphology and in habits
The chief characteristic of the water fleas is that the main part of the body is enclosed in a kind of shell, with the appearance of
two lids, but made of one piece. They are interesting animals for the microscopist. Because you can see through them, you can
study for instance the beating of the heart and follow the course of the blood cells round part of the body. Their sizes differ
from several hundred microns to more than five millimetre for the larger species.
The common water flea, Daphnia pulex can be found in almost all sorts of eutrophic (rich in nutrients) waters. They reproduce
in summer mostly parthenogenetic, that is, the eggs develop without undergoing fertilization.
At the end of the summer, some of the eggs develop into the smaller males, capable of fertilizing the eggs in females, which
then develop into the so called 'winter eggs'; mostly only one or two are present in the females. These eggs can also be found in
populations under stress, such as during the drying up of a pond.
Chlorella sp
Oscillatoria sp
Cylindrical or sometimes slightly tapering, unbranched filaments (trichomes),
often with a rounded or capitate apical cell. Other cells are discoid, with further
developing cross-walls.
Species of Oscillatoria occur in a diverse range of conditions, in damp soil or on
dripping rocks, in freshwater, in the sea and in hot springs. Some are tolerant of
high levels of organic pollution and some are shade-tolerant and able to survive in
water below blooms of green algae. In water they may be benthic or planktonic.
O. rubescens is a red species that can form conspicuous red blooms in
eutrophicated lakes
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Oedogonium sp
• Oedogoniales - Members of this smallest group have a complex
multiflagel ate crown on their swimming spores. All are filamentous,
oogamous, and have net-like chloroplasts.
Ulothrix sp
Ulothrix have band shaped chloroplast
Gomium
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Oedogonium
Spirogyra, a green algae
Members of this smallest group have
a complex multiflagellate crown on
their
swimming
spores.
All are
filamentous, oogamous, and have
net-like chloroplasts
Oogamous: Characterized by or having small motile male gametes and
large nonmotile female gametes
Cladophora
Eudorina indica
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Euglena sp
Volvox aureus
Chlamydomonas reinhardtii
و هذه الصفحة ابحثي عما يمكن أن ينفعك فيها
http://www.botany.uwc.ac.za/algae/
على العموم جربي ابحثي بنفسك لكي تتعودي و بحث التخرج لا يكون مشكلة
إن شاء الله أكون أفدتك
لا تنسي الدعاء فأنا محتاجة إليه