Loading....
Coupon Accepted Successfully!

 

Thallophyta - Algae


Algae and fungi are considered together in Thallophyta, though there is a basic difference in their mode of nutrition. It is autotrophic in algae, whereas fungi exhibit heterotrophic nutrition. Algae usually occur in a variety of habitats such as water, land as well as on the other plants and even animals. Some grow in marine water and are called seaweeds. The thallus is unicellular flagellated (Chlamydomonas) or non-flagellated (Chlorella), a colonial form (Volvox) or may even be of the filamentous type (Ulothrix and Spirogyra). In some forms, the thallus is flattened and leaf-like (Laminaria) and anchors to the rocks with the help of hold-fast. The unicellular protist algae are included in these figures for comparison. A variety of pigments in algae provide different colours. The green algae have mainly chlorophyll a and b along with carotenoids as photosynthetic pigments. The chloroplasts containing green pigment are either gardle shaped or are of spiral type. The other pigments like fucoxanthin (brown),  phycoerythrin (red) and phycocyanin (blue) provide colour to the algal forms. The red algae may secrete and deposit calcium carbonate and appear like corals. Common red algae are Polysiphonia, Batrachospermum and Gelidium. Algae reproduce vegetative by fragmentation (Sargassum), budding or tuber formation. A variety of motile and non-motile spores are involved in their asexual reproduction. The life cycle has distinct haploid and diploid phases exhibiting phenomenon of alternation of generations. Based on the pigment colour, nature of stored food material and cell organisation, algae are further sub-divided into green (Chlorophyceae), brown (Phaeophyceae) and red (Rhodophyceae), etc.
 

Green Algae : Ulothrix


The other pigments like fucoxanthin (brown), phycoerythrin (red) and phycocyanin (blue) provide colour to the algal forms. The red algae may secrete and deposit calcium carbonate and appear like corals. Common red algae are Polysiphonia, Batrachospermum and Gelidium. Algae reproduce vegetatively by fragmentation (Sargassum), budding or tuber formation. A variety of motile and non-motile spores are involved in their asexual reproduction. The life cycle has distinct haploid and diploid phases exhibiting phenomenon of alternation of generations. Based on the pigment colour, nature of stored food material and cell organisation, algae are further sub-divided into green (Chlorophyceae), brown (Phaeophyceae) and red (Rhodophyceae), etc.


Algae : Sargassum





Test Your Skills Now!
Take a Quiz now
Reviewer Name