Search results
Results from the WOW.Com Content Network
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.
In general, an asexual phase exists where the seaweed's cells are diploid, a sexual phase where the cells are haploid, followed by fusion of the male and female gametes. Asexual reproduction permits efficient population increases, but less variation is possible.
Sphaeroplea consists of unbranched filaments of cells, one cell thick. Cells are usually 10–50 μm in diameter, but one variety can reach up to 170 μm in diameter. Cells are cylindrical, several times longer than wide, with a linear series of alternating vacuoles and cytoplasmic zones containing nuclei and chloroplasts.
Green algae are often classified with their embryophyte descendants in the green plant clade Viridiplantae (or Chlorobionta). Viridiplantae, together with red algae and glaucophyte algae, form the supergroup Primoplantae, also known as Archaeplastida or Plantae sensu lato. The ancestral green alga was a unicellular flagellate. [20]
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 ...
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.
Volvox is a polyphyletic genus of chlorophyte green algae in the family Volvocaceae. Volvox species form spherical colonies of up to 50,000 cells, and for this reason they are sometimes called globe algae. They live in a variety of freshwater habitats, and were first reported by Antonie van Leeuwenhoek in 1700.
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 ...