Oedogonium belongs to chlorophyta. Fresh water alga .We can easily identify with the help of cap cells. The plant body is haploid and the life cycle is also haplontic type.
This PowerPoint helps students to consider the concept of infinity.
Oedogonium LifeCycle /vegetative cell/Asexual and sexual reproduction.
1. The filament is attached with the help of
colourless disc like hold fast to the substratum.
Plant body is of filamentous, unbranched.
It is aquatic found in permanent, semipermanent
fresh water of pools, tanks ditches etc.
Presence of large single nucleus and a reteculate
chloroplast with numerous pirenoids.
Presence of caps in the dividing cells.
The cell wall with outer chitin, middle pectin
and inner cellulose.
26. 1.By multi flagellate zoospores.
Any vegetative cell except hold fast and
apical cell may function as zoosporangium
and form single zoospore.
In each zoospore flagella are arranged in a
ring like around a colourless beak like area.
2. By Akinetes------- In unfavourable
conditions thick walled akinetes are formed
in chains of 10-40 in vegetative cells with
reserve food starch and oil. They germinate
on favourable conditions and give rise to new
oedogonium filaments.
27. Oogamous type
Female sex organ Oogonium and male sex
organ antheridium.
Oedogonium may be homothallic or
heterothallic
Antheridia may develop in macrandrous type
or nonnandrous type.
28. In macrandrous male sps antheridia are
produced in rows on normal sized filaments
but in nonnandrous sps the antheridia are
produced on special dwarf male filaments.
The dwarf male filamens are produced by
the germination of multiflagellate
androspore.
29. Any vegetative cell vegetative cell except
holdfast cell may act as antheridial mother
cell.
It divides and redivides to form a row of 8-40
antheridia.
The protoplast in each antheridium may
produce single or two antherozoids or
spermatozoids.
The antherozoid is like zoospore, but small in
size poorer in chlorophyll and fewer flagella
30. Dwarf males or nonnandria are special dwarf filaments on which
antheridia are born.
The dwarf males attach themselves to the filament bearing
oogonium.
The dwarf males are produced by the germination of special types
of zoospores, called androspores that are formed singly within the
androsporangium.
Androsporangium is quite similar in appearance to the antheridia
of macrandrous male spsnand they are developed in a row from the
vegetative cells in the same manner as that of the antheridia of
macrandrous malesps. Each androsporangium produce single
androspore.
Androspore is intermediate in size between zoospore and
antherozoid.
Androspore attach to the wall of the oogonium and germinates and
form dwarf males.
In nonnandrous sps both antheridia and oogonia are on the same