Search results
Results from the WOW.Com Content Network
Green algae have chloroplasts that contain chlorophyll a and b, giving them a bright green colour, as well as the accessory pigments beta carotene (red-orange) and xanthophylls (yellow) in stacked thylakoids. [12] [13] The cell walls of green algae usually contain cellulose, and they store carbohydrate in the form of starch. [14]
Diagram of the plant cell, with the cell wall in green. Cell walls serve similar purposes in those organisms that possess them. They may give cells rigidity and strength, offering protection against mechanical stress. The chemical composition and mechanical properties of the cell wall are linked with plant cell growth and morphogenesis. [11]
The structure of these algae is unicellular, and lacks flagella.Although most desmid species are unicellular, some genera form chains of cells, called filaments. A few genera form non-filamentous colonies, with individual cells connected by threads or remnants of parent cell walls.
Chlorella is a genus of about thirteen species of single-celled or colonial green algae of the division Chlorophyta. The cells are spherical in shape, about 2 to 10 μm in diameter, and are without flagella. Their chloroplasts contain the green photosynthetic pigments chlorophyll-a and -b.
Desmodesmus species usually produce colonies of more than one cell, but single cells (unicells) may be found as well. [5] These single cells may be confused with Lagerheimia, a genus of single-celled algae. [6] The cell wall of Desmodesmus consists of an outer layer with a net-like structure, with "rosettes" of tubes underneath. [7]
Depending on the species, Chlorophyceae can grow unicellular (e.g. Chlamydomonas), colonial (e.g. Volvox), filamentous (e.g. Ulothrix), or multicellular. [example needed] They are usually green due to the presence of chlorophyll a and chlorophyll b; they can also contain the pigment beta-carotene.
The chlorophyte and charophyte green algae and the embryophytes or land plants form a clade called the green plants or Viridiplantae, that is united among other things by the absence of phycobilins, the presence of chlorophyll a and chlorophyll b, cellulose in the cell wall and the use of starch, stored in the plastids, as a storage polysaccharide.
Chlamydomonas reinhardtii is a single-cell green alga about 10 micrometres in diameter that swims with two flagella.It has a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and an eyespot apparatus that senses light.