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Pearsall and Loose (1937) [5] reported the occurrence of motile cells in Chlorella. Bendix (1964) [ 6 ] also observed that Chlorella produces motile cells which might be gametes. These observations have an important bearing on the concept of the life cycle of Chlorella, which at present is considered to be strictly asexual in character.
Many algae, particularly species of the Characeae, [62] have served as model experimental organisms to understand the mechanisms of the water permeability of membranes, osmoregulation, salt tolerance, cytoplasmic streaming, and the generation of action potentials. Plant hormones are found not only in higher plants, but in algae, too. [63]
In general the fungal species that partner in lichens cannot live on their own, while the algal species is often found living in nature without the fungus. Trentepohlia is a filamentous green alga that can live independently on humid soil, rocks or tree bark or form the photosymbiont in lichens of the family Graphidaceae .
The Zygnematophyceae, formerly known as the Conjugatophyceae, generally possess two fairly elaborate chloroplasts in each cell, rather than many discoid ones. They reproduce asexually by the development of a septum between the two cell-halves or semi-cells (in unicellular forms, each daughter-cell develops the other semi-cell afresh) and sexually by conjugation, or the fusion of the entire ...
Zygnema is a genus of freshwater filamentous thalloid alga comprising about 100 species. [4] A terrestrial species, Z. terrestre, is known from India.Zygnema grows as a free-floating mass of filaments, although young plants may be found anchored to streambeds with a holdfast.
Algae lack the various structures that characterize plants (which evolved from freshwater green algae), such as the phyllids (leaf-like structures) and rhizoids of bryophytes (non-vascular plants), and the roots, leaves and other xylemic/phloemic organs found in tracheophytes (vascular plants).
Yellow-green algae or the Xanthophyceae (xanthophytes) are an important group of heterokont algae. Most live in fresh water, but some are found in marine and soil habitats. They vary from single-celled flagellates to simple colonial and filamentous forms.
The three cell surfaces of an Oedogonium filamentous cell consist of polysaccharides, proteins and lipids which provide several functional groups capable of binding to heavy metal ions. [ 10 ] [ 11 ] Due to their position at the surface of a body of water, algal blooms can block out the sunlight from other organisms and deplete oxygen levels in ...