Spirogyra has a spiral ribbon like chloropast
nucleus is in center of cells
reproduces by conjugation,material of one filament enter cells of another filament
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Volvox is green algal colony
its motile as it has a flagella
has both sexual as well as asexual reproductions
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Diatoms
in addtion to chlorophyll has a yellow brown pigment
the cell wall is impregnated with silica
photosynthetic
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Lichens
combination of fungus and algae or cynobacterium
found in extreme conditions,artic tundra ,deserts etc
Crustose lichens on a wall
fungus surrounds the algae
lichen are poikilihydric (survives in low levels of water)
algal components is photosynthetic
reproduce asexually or vegetatively
used as food
may also be used as antibiotic as it reduces the growth of bacteria
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Fucus
Fucus is in genus of brown alga found on rocky shores worldwide
The thallus is perennial
Gas-filled (air-vesicles) are present in pairs in some species, one on either side of the midrib.
These algae have a relatively simple life cycle and produce only one type of Thallus which grows to a maximum size of 2 m
They are dominant on the shores of the british isles, the northeastern coast of North America and California .
used as fertiliser and to make soda ash
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Grantia
phylum Porifera.
They are primitive, sessile, mostly marine, water dwelling filter feeders that pump water through their bodies to filter out particles of food matter..
Water enters the sponge through a series of incurrent canals and passes through internal pores called prosopyles into the radial canals,
Radial cannals are lined with flagellated collar cells also called Choanocytes.
- choanocytes that keeps water moving through the sponge.
Direction of water flow . radial canals, ==>water then enters the central spongocoel ==> to exit through a single opening called an osculum.
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Obelia
Phyllum Cnidaria
Class Hydrozoa
A - new polyp forming, B - reproductive polyp, C- feediing
Obelia is a colonial marine organism that is found attached to seaweeds, rocks, shells or pilings in the shallow waters off seacoasts.
alternates between a polyp stage (which is the asexual generation) and a medusa stage (which is the sexual generatio
The plantlike colony consists of numerous branches, which terminate in two kinds of polyps. The feeding, or nutritive polyps possess tentacles and resemble Hydra.
The reproductive polyps are club-shaped and lack tentacles.
