General characteristics of Algae: 1. Algae include simple unicellular or multicellular plants characterised by the presence of a green pigment called chlorophyll. 2. They are mostly aquatic, though a few are terrestrial. 3. Aquatic algae grow in fresh water or marine water. 4. The plant body of Algae show variety in their size and organization. They may be unicellular or multicellular. The multicellular algae may be unbranched filamentous or branched filamentous. 5. The cell wall in algae is made up of two layers- an outer pectin and an inner cellulosic. 6. Photosynthetic pigments present in algae include chlorophyll a, chlorophyll b, chlorophyll c, chlorophyll d, xanthophylls and phycobilins. 7. Algae reproduce vegetatively by fragmentation and cell division, asexually by spores and sexually by means of gametes. 8. Algae in their life cycle show alternation of generations in which the haploid gametophytic phase alternates with the diploid sporophytic phase.

Examples : Spirogyra and Chara.