LICEO SCIENTIFICO “LE FILANDIERE”

CLASS 2ND B presents...

BIODIVERSITY

With English teacher Gnesutta & Biology teacher D’angela

ANABAENA

Anabaena is a genus of filamentous cyanobacteria, or blue-green algae.

It is very important because it provides a model for the study of gene differentiation in the formation of heterocysts.

Anabaena are heterocyst-forming, photoautotrophic cyanobacteria that perform oxygenic photosynthesis. Anabaena grow in long filaments of vegetative cells.

It is also commonly accepted that cyanobacteria play a key role in the manufacturing of oxygen during the Precambrian period of Earth's history.

By David Bottan

An electron microscope image

Nostoc

Nostoc is a genus of nitrogen-fixing cyanobacteria. Often it forms colonies composed of filaments of moniliform cells in a gelatinous sheath: they are called also “Spring foam” for this aspect. Nostoc can be found in soil, on moist rocks, at the bottom of lakes and springs (both fresh than salt water) and rarely in marine habitats. It may also grew symbiotically within the tissues of plants providing nitrogen to its host through the activity of differentiated cells known as heterocysts. These bacteria contain photosynthetic pigments in their cytoplasm to perform photosynthesis.

By Giacomo Castellarin

Spirogyra

Spirogyra is a genus of filamentous green algae of the order Zygnematales, named for the helical or spiral arrangement of the chloroplasts that is diagnostic of the genus. It is commonly found in freshwater areas, and there are more than 400 species of Spirogyra in the world. Spirogyra measures approximately 10 to 100μm in width and may stretch centimeters long. This particular algal species in commonly found in polluted water.Spirogyra is unbranched with cylindrical cells connected end to end in long green filaments. The cell wall has two layers: the outer wall is composed of pectin that dissolves in water to make the filament .The cytoplasm forms a thin lining between the cell wall and the large vacuole it surrounds. Pectin:polysaccharide

By Marco Cattaruzza

MIXED DESMIDS: IN DETAILS MISCRASTERIAS

This kind of desmid could be easily found in all the freshwater habits. It`s threatened by fertilizers. Tipicalli one-celled organism,Sometimes they gather in filamentous or colonial. Each organism is divided into two symmetrically halves.Miscraterias, the one in the image, is one of the largest desmidsthat could be found (about one third of a millimeter).

Each half of the cell contains a single chloroplast. It reproduce both sexually and asexually. Asexually, it reproduces by a simple division. Sexually it reproduces either by nuclear materials exchange and by fusion of two organism to create a new one. Spores are rare.

Made by Piero Cordenos

Draparnaldia is a green alga in which the filaments are formed in whorls around a central, branching thread. Usually it presents mucus material surrounding the filaments.

Draparnaldia

Draparnaldia is a genus of algae of the family Chaetophoraceae. It’s an autotrophic and eucaryota organism.

By Lucia Del Bianco

There are two different types of Colpidium: Colpidium colpoda whose dimension may arrive to 150 μm and Colpidium striatum that is only 50 μm long.

Typically it is found at the water's edge at a mean distance from sea level of 12 meters. It occurs in both freshwater and saltwater.

Colpidium is an eukaryotic unicellular organism. It is a ciliated protozoan and it is free-living (it isn’t a parasite). Like the other ciliated organisms, it has a macronucleos and a micronucleos.

COLPIDIUM

cilium

nucleus

By Eleonora Giro

ChlamydomonasChlamydomonas is a genus of green alga, very common with 500 species in the genus .They are unicellular flagellates and can be found in fresh water and humus.Most species are obligate phototrophs but some  are heterotrophs can grow in the dark in the presence of acetate as a carbon source.

Morphology:Chlamydomonas has often:• An oval shape.• Two flagella with contractile vacuoles on the base.• Pyrenoid with starch granule is present in the

posterior end • of the chloroplast.

  

By Emanuele Milan

Nucleus

Cell Membrane

Cytoplasm

Paramecium is an unicellular organism of the group of Protozoa. In every cell there is a very large nucleus, the cytoplasm with all the organelles and the cell membrane covered with cilia that permit the Paramecium to move. The presence of these short filaments give the name of Ciliate to this group of Protista.

Paramecia feed on bacteria: they are introduced into the cell through

an opening in the Cell Membrane, called the Cytostome surrounded by

cilia.

Cilia

Zygnema

The cells have two cloroplasts with a star shape.

The Zygnema lives in colonies in still water.

It is an alga : plant-like microorganism.

Zygnema is an eukaryotic microorganism.By Federica Nan 2b

Cladophora is one of the most common marine or fresh water chlorophytes in the northern Emisphere. It is always green.It contains many species that are very hard to tell apart and classify, mainly because of the great variation in their appearances, which is affected by habitat, age and environmental conditionsThe alga is attached to a solid substratum by rhyzoidal basal cells.It’s branching filaments are up to 30 cm long.Cladophora is interesting for several reasons:1) It has atipical growth2) The chloroplasts are net-shaped, containing

numerous nuclei and pyrenoids, protein grains.

By Steven Petty

Trypanosomes are unicellular and heterotrophic cells.Trypanosomes are parasitic organisms with a spindle-shaped body and a flagellum.

By Edoardo Piallini

DiatomsBy Matteo Roncadin

Nucleus

Membrane

Dna(deoxyribonucleic acid)

Diatoms are protoctista and some of them are part of the marine plankton.

Bilaterally symmetrical diatoms grow attached to debries or to water plants forming tree like

colonies or slimy masses.

Other diatoms live solitary or form ribbon like colonies on the bottom of the water

Radiolarians (or radiolaria) are protozoa that produce intricate mineral skeletons, typically with a central capsule dividing the cell into inner and outer portions, called endoplasm and ectoplasm. They are found as zooplankton throughout the ocean and represent important fossil. They have many needle-like pseudopodia, with which they can move.

Radiolare

The type of reproduction is asexual and the shell is divided into 2 parts between the daughter cells.

By Simone Schincariol

Reproduction: Reproduction in Ulothrix takes place by means of

vegetative, asexual and sexual methods.

Ulothrix

General information: In taxonomy Ulothrix is a genus of algae. Ulothrix is a genus of filamentous green algae, generally found in fresh and marine water. Its cells are

generally wider than long. This alga thrives in low temperatures of spring and winter.

Structure: The central body is not branched and consists of filaments. The cells of the filaments are arranged in the end. They are rectangular or a little square.

By Matto Sclippa

The motile alga Chlorella is important in the food chain of

the freshwater habitat, providing nutrition for a wide variety of micro organisms and filter feeders such as

water fleas.

Chlorella is photographed in a mass of mucilage in which many hundreds of similar organisms were also embedded, and as such, members of one of the

colonial varieties which have this form. Interestingly, each of the individuals is capable of making

its way out of the containing matrix, undergoing elongation

and living an independent existence.

CHLORELLABy Ilaria Semenzato

• Spirogyra is a green-alga formed into simple filaments.

• The wall cell has got two layers: the external layer is composed of cellulose, the internal one of pectina.

• One of the most interesting characteristic of these organisms is the shape of their chloroplast that is ribbon -like and organized as a spiral. As all the green algae, the starch is accumulated in the chloroplasts.

• The sexual reproduction is realized through the migration of gametes into cytoplasmatic bridges connected the cells while the asexual reproduction is realized through cellular mitosis and fragmentation of the filaments.

• The Spirogyra is relatively very common in clean waters (eutrophyc water) and the cells primarily develop during spring.  

By Laura Spinato

Spiral

Intercellular bridge

Nucleus

Ceratium hirundinella by Mattia Vadori

The Ceratium hirundinella is a dinoflagellate. It’s an eukaryotic protist. Dinoflagellates use their flagella to move.It’s formed by two parts of armor-like cell wall divided.Each part has got horns: the upper-part only one, the lower one usualy three.It lives in marine habitat, it’s a free-living member of the plankton.It can be heterotroph or autotroph. When it’s autotroph, the cloropasts make it green or brown.

Nucleus

Lower-partUpper-part

Horns

Flagellum

By Giulio ZannierPlankton includes floating marine organisms, that are transported by currents and waves, like micro-organisms (unicellular algae, protozoa, etc...), multicellular algae, larvae, small animals (crustaceans) and jellyfish.

The organisms forming plankton are different for size and shape and in the way of nutrition and use energy. They are present both in salt water and in fresh water such as lake and bogs.

In the plankton there are two main groups of organisms: phytoplankton and zooplankton.

PLANKTON

PhytoplanktonThe concentration of phytoplankton is mainly caused by light because its metabolism (autotrophic) is based on photosynthesis. In fact, the phytoplankton is more concentrated in the superior layers where the sunlight can pass through. 

However, they reach the maximum density in a few meters below the sea surface because at that level the conditions for their development are the most favourable.

Zooplankton

Instead you can find Zooplankton at different levels in the water because it is formed by heterotrophic organisms that don't use light for life. They can comprehend simple unicellular organism or more complex one like fish larvae.

PRESENTATION BY CLASS 2^B “LICEO SCIENTIFICO “LE FILANDIERE”

SAN VITO AL TAGLIAMENTO

THE END