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To some degree, the distribution of algae is subject to floristic discontinuities caused by geographical features, such as Antarctica, long distances of ocean or general land masses. It is, therefore, possible to identify species occurring by locality, such as " Pacific algae" or " North Sea algae".
A very large algae bloom in Lake Erie, North America, which can be seen from space. An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in fresh water or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments.
Haploid algal cells (containing only one copy of their DNA) can fuse with other haploid cells to form diploid zygotes. When filamentous algae do this, they form bridges between cells, and leave empty cell walls behind that can be easily distinguished under the light microscope. This process is called conjugation and occurs for example in Spirogyra.
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.
Chlorophytes are eukaryotic organisms composed of cells with a variety of coverings or walls, and usually a single green chloroplast in each cell. [4] They are structurally diverse: most groups of chlorophytes are unicellular, such as the earliest-diverging prasinophytes, but in two major classes (Chlorophyceae and Ulvophyceae) there is an evolutionary trend toward various types of complex ...
The cells contain a single chloroplast which is parietal (lying against the inner side of the cell membrane), with a single pyrenoid that is surrounded by grains of starch. [1] Reproduction occurs by the formation of autospores; zoospores or gametes are not known to be produced in Chlorella. Autospores are released by a tear in the cell wall.
Chlamydomonas (/ ˌ k l æ m ɪ ˈ d ɒ m ə n ə s,-d ə ˈ m oʊ-/ KLAM-ih-DOM-ə-nəs, -də-MOH-) is a genus of green algae consisting of about 150 species [2] of unicellular flagellates, found in stagnant water and on damp soil, in freshwater, seawater, and even in snow as "snow algae". [3]
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 ...