Life cycle of Ectocarpus siliculosus. Both Ectocarpus sexual and asexual life cycles are displayed. Gametes (right side) released from WT male gametophytes . The life history of Ectocarpus fasciculatus var. refractus (Kiitz.) Ardis. from Roscoff , France, has been studied in culture. This species proved to be the sporophytic. the sexual pheromones and infection of Ectocarpus by viruses. A proposition to (the life cycle can be completed in three months) and the ease with which.
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According to KnightSchussing and Kothbaouerrarely the zoospores released from unilocular sporangia, show pairing and fusion but the fate of such zygotes is not known. Each protoplast then metamorphoses into a pear-shaped zoospore. Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top. In epiphytic forms the prostrate system is well developed and the erect system is reduced. The cells then undergo several vertical divisions thus a multi- chambered structure is formed i.
The gametangial initial divides transversely to form a row of cells. The physodes contain polyphenols, probably function as lysosomes. The apical cell enlarges and functions as sporangial initial.
This multicellular structure is called plurilocular sporangium. Growth of the prostrate system is apical, but that of erect threads shows considerable diversity.
They found diploid plants bearing both unilocular and plurilocular reproductive structures having a reduction division in the former and none in the ectocrpus.
Life Cycle of Ectocarpus (With Diagram) | Algae
Both haploid and diploid plants are morphogically identical Fig. The asexual reproduction takes places with the help of biflagellate zoospores. The sexual reproduction may be isogamous, anisogamous or oogamous. Sexual reproduction may be isogamous, anisogamous or oogamous type.
The gametes ljfe biflagellate, motile and are produced in plurilocular gametangia borne on haploid or unisexual plants.
After some time they get free from the gelatinous mass and swim freely in water. In ecctocarpus species of Ectocarpus gametes from same plant can fuse to form a zygote showing isogamous reproduction.
The anterior flagellum is longer, pantonematic and directed forward while the posterior is shorter, acronematic and directed backward Fig. It is much branched and well-developed.
Quick Notes on Ectocarpus (With Diagram) | Algae
In physiological anisogamy both the uniting gametes are morphologically similar but in morphological ectocar;us female gamete is larger than the male gametes. It repeatedly undergoes transverse divisions to form a row of cells Fig. Here’s how it works: The zoospores are biflagellate having one whiplash and other tinsel-type of flagellum.
The sporophytic plant again develops unilocular and plurilocular sporangia. The individual cell uninucleate and contains plate-like or band-shaped chloroplast with or without pyrenoids. Here’s how it works: Classification of Ectocarpus 2. The prostrate system serves the function of anchorage with the substratum or on other plants and the erect system is photosynthetic and bears reproductive organs.
Like unilocular sporangia, the plurilocular sporangia also develop from the terminal cells of the branchlets of diploid sporophytic plant.
They cyclf motile for about ectocarpjs minutes. They germinate to produce new diploid sporophytic plant. These plants are called gametophytic plants as on maturity they bear plurilocular gametangia.
The single nucleus of the young unilocular sporangium divides and redivides producing 64 nuclei. After sometime one male gamete fuses egg to make zygospore and other gametes detach themselves from female gamete.
This is one of the best-known brown algae containing many species. The filaments can only be differentiated from each other through cytological studies and the nature of reproductive structure a particular filament bears. The smaller gametes are produced in lfie and the larger are produced in bigger mega-gametangia. During fertilisation, many male gametes encircle the female gamete and get entangled by the anterior large flagellum.
The alga has an isomorphic, alternation of generations, the gametophyte and the spoiophvte being essentially alike in appearance. The cell which functions as sporangial initial Fig.
Ectocarpus – Wikipedia
These two types of zoosporangia may be produced on the same plant or on different plants. The active male gametes cluster around female gamete and cling themselves by their anterior flagellum. The unilocular zoosporangia form haploid zoospores and the plurilocular sprogania form diploid zoospores. The sexual lifr is both isogamous and anisogamous type. Occurrence, Structure and Reproduction.
Quick Notes on Ectocarpus (With Diagram) | Algae
The medium sized meso-gametangia give rise to medium size gametes. They may also taper into hairs. It takes place by zoospores. The diploid plants ectocagpus both unilocular and plurilocular sporangia. The zoospores after being discharged remain in spherical mass at the apex of sporangium.
These diploid zoospores multiply only sporophytic plants and they do not play any role in alternation of generation. Some species of Ectocarpus are epiphytic e. In this article we will discuss about Ectocarpus.