Notes on the important Characteristic of Alage

1. The algae are mostly aquatic in habit.

They are found in fresh or salt water.

2. The plant body is a thallus. i.e. not differentiated into root, stem and leave

3. Algae show a great diversity in organization of thallus. Unicellular micro! Chlamydomonas (motile) and Chlorella (non-motile) represent the sic forms of algae.

4. Simple multi cellular, un branched filamentous form is observed in Spirogyara. Macrocystis pynifera is a gaint marine algae about 50 m in length.

5. Cells of the thallus contain the green pigment – chlorophyll.

6. The mode of nutrition is autotrophic.

7. Algal cells are eukaryotic except the members of blue green algae (Cyanobacteria). Cells are generally uni nucleate. Multinucleate condition is also seen, e.g. Vaucheria.

8. Cell wall is made up of cellulose.

9. Starch occurs as the reserve food material in cells.

10. Reproduction in algae may be vegetative, asexual and sexual. Vegetative reproduction takes place by fragmentation of the thallus.

Asexual reproduction is effected by the formation of motile or non-motile spores such as zoospores, aplansopores, akinetes etc. Sexual reproduction may be isogamous, anisogamous or oogamous.

11. Sex organs are either unicellular or multi cellular but non-jacketed.

12. Embryo development never occurs.