T. Sagma, Department of Botany, IGGC, Tezu.
REPRODUCTION IN ALGAE
CHLOROPHYCEAE (GREEN ALGAE) -
All the three major types of reproduction such as vegetative, asexual and sexual are secn among the
members of Chlorophyccae.
VEGETATIVE REPRODUCTION -
It takes place by the fragmentation of the filament or the splitting of the colony into two or more pieces.
Each piece then grows by cell division into a new independent individual. Fragmentation in filamentous type
results from the accidental breaking of the filament, natural separation of the parts of a filament owing to
some external mechanical pressure, or from consumption or dying out of intercalary cells of the filament
during asexual and sexual reproduction. Cell division is the common method of vegetative reproduction
among unicllular forms.
ide ualK lhaut
Himthdios
dig ngmentlas is Spkegyla
ASEXUAL REPRODUCTION -
The asexual reproduction is brought about by the formation of spores either within vegetative cells
(Uiothrix) or within metamorphosed vegetative cells i.e. sporangia (Trentepohlia). The number of spores
within each cell varies from one (Oedogonium) or many (in most algae). The spores may be either motile
and naked or non-motile and provided with distinct walls. The motile spores are called,zoospores" and the
cell which produces such spores are called,z00sporangium". The protoplast ofthe zoosporangium breaks
up into several pieces, each of which develops 2-4 whiplash flagella of equal length at the anterior end and
thus becomes motile in nature.The zoospores are liberated either through (a) a terminal pore or a lateral pore
develop on the wall of the mother cell, or (b) by the gelatinization or breaking the wall of the
zoosporangium. After a period of rest, a zoospore germinates into a new individual adult plant.
Sometimes during unfavourable conditions, non-motile spores with prominent cell walls called
aplanospores" are produced. The aplanospores come out by the rupture or decay of the mother cell
(sporangium) wall. In some cases, the wall of the aplanospore is surrounded by a very thick wall. In such
cases, it is called a ,hypnospore". Sometimes, ,akinetes are also formed during asexual reproduction
(Pithophora). All these spores germinate into new plants
Nuckus
Nu cleus
lueleu call-oall Tkich
cull-all
Aphmesese
Page 1 of 8
, -Autsoo
pe isoui
REPRODUCTION IN ALGAE
CHLOROPHYCEAE (GREEN ALGAE) -
All the three major types of reproduction such as vegetative, asexual and sexual are secn among the
members of Chlorophyccae.
VEGETATIVE REPRODUCTION -
It takes place by the fragmentation of the filament or the splitting of the colony into two or more pieces.
Each piece then grows by cell division into a new independent individual. Fragmentation in filamentous type
results from the accidental breaking of the filament, natural separation of the parts of a filament owing to
some external mechanical pressure, or from consumption or dying out of intercalary cells of the filament
during asexual and sexual reproduction. Cell division is the common method of vegetative reproduction
among unicllular forms.
ide ualK lhaut
Himthdios
dig ngmentlas is Spkegyla
ASEXUAL REPRODUCTION -
The asexual reproduction is brought about by the formation of spores either within vegetative cells
(Uiothrix) or within metamorphosed vegetative cells i.e. sporangia (Trentepohlia). The number of spores
within each cell varies from one (Oedogonium) or many (in most algae). The spores may be either motile
and naked or non-motile and provided with distinct walls. The motile spores are called,zoospores" and the
cell which produces such spores are called,z00sporangium". The protoplast ofthe zoosporangium breaks
up into several pieces, each of which develops 2-4 whiplash flagella of equal length at the anterior end and
thus becomes motile in nature.The zoospores are liberated either through (a) a terminal pore or a lateral pore
develop on the wall of the mother cell, or (b) by the gelatinization or breaking the wall of the
zoosporangium. After a period of rest, a zoospore germinates into a new individual adult plant.
Sometimes during unfavourable conditions, non-motile spores with prominent cell walls called
aplanospores" are produced. The aplanospores come out by the rupture or decay of the mother cell
(sporangium) wall. In some cases, the wall of the aplanospore is surrounded by a very thick wall. In such
cases, it is called a ,hypnospore". Sometimes, ,akinetes are also formed during asexual reproduction
(Pithophora). All these spores germinate into new plants
Nuckus
Nu cleus
lueleu call-oall Tkich
cull-all
Aphmesese
Page 1 of 8
, -Autsoo
pe isoui
