Pyrenoids on Xanthophyceae
Usually absent
Antheridia (slender, hook-shaped)
Male sex organs
Oogonia (spherical)
Female sex organs
- (Non-motile spores produced under unfavorable conditions)
- Produced inside aplanosporangium.
- like zoospore except flagella are absent
Aplanospores
- (develop under adverse conditions) Are short, thick walled, gelatinous.
- produced in dichotomous branches in rows (Gongrosira stage)
- return of favorable conditions, directly forms new plants
Akinetes
ECONOMIC IMPORTANCE of Xanthophyceae
- Contaminent of water
- Treatment plants
- Water supply
- Toxin production
- Stabilization process of excess mud
- Production of oxygen
- As food
- For recreational uses
- Yellow green filamentous alga
- Branching is monopodial but appears dichotomous
- Reserve food material is oil
Vaucheria
Vegetative Reproduction By?
fragmentation (thallus breaks up accidentally)
Present, two unequal, situated anteriorly. Longer one tinsel and shorter one whiplash
Flagella of Xanthophyceae
Why yellow green algal known as heterokonate?
because there are two structurally different flagella (or sometimes one flagellum)
composed of pectic substances and sometimes silica.
Cell wall og yellow green algal
Pigments of yellow green alga
° chlorophyll a, e and c,
◦ β-carotene
◦ Xanthophylls.
Grows in the form of dense tufts on damp garden soil, moist walls, stagnant ponds, ditches
Vaucheria
Thalli of vaucheria are multinucleated, lack cross- walls and are called
coenocytic
Vaucheria Reserve food material as
oil
In this method, the thallus breaks up accidentally into short segments, which finally form new individuals.
Fragmentation of Vaucheria
Multiflagellate & multinucleate, produced in club shaped sporangium.
Zoospores in Vaucheria.
Akinetes are produced in dichotomous branches in rows, this stage is called ………
Gongrosira stage
develop under adverse conditions Are short, thick
walled, gelatinous
Which type of reproduction?
Akinetes (Asexual)
Non-motile spores produced under unfavorable conditions, flagella are absent.
Which type of reproduction?
Aplanospores (Asexual)
Non-motile spores produced under unfavorable conditions, flagella are absent.
Which type of reproduction?
Aplanospores (Asexual)
