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Kelp have had to adapt dispersal methods that can make successful use of ocean currents. Buoyancy of certain kelp structures allows for species to disperse with the flow of water. [21] Certain kelp form kelp rafts, which can travel great distances away from the source population and colonize other areas.
Non-cellular life, also known as acellular life, is life that exists without a cellular structure for at least part of its life cycle. [1] Historically, most definitions of life postulated that an organism must be composed of one or more cells, [2] but, for some, this is no longer considered necessary, and modern criteria allow for forms of life based on other structural arrangements.
Opinions differ on whether viruses are a form of life or organic structures that interact with living organisms. [34] They are considered by some to be a life form, because they carry genetic material, reproduce by creating multiple copies of themselves through self-assembly, and evolve through natural selection .
The closest relatives to animals are the choanoflagellates (~360 species), free-living flagellates that feed through a collar of microvilli surrounding a larger cilium and often form colonies. [118] The Ichthyosporea (>40 species), otherwise known as mesomycetozoans, are a group of fungus-like pathogenic holozoans specialized in infecting fish ...
It can cause vomiting and diarrhea. [61] The so-called "stinging seaweed" Microcoleus lyngbyaceus is a filamentous cyanobacteria which contains toxins including lyngbyatoxin-a and debromoaplysiatoxin. Direct skin contact can cause seaweed dermatitis characterized by painful, burning lesions that last for days. [1] [62]
It has a polymorphic life cycle, ranging from free-living cells to large colonies. [33] It has the ability to form floating colonies, where hundreds of cells are embedded in a gel matrix, which can increase massively in size during blooms. [34] As a result, Phaeocystis is an important contributor to the marine carbon [35] and sulfur cycles. [36]
Ascophyllum nodosum is harvested for use in alginates, fertilisers, and the manufacture of seaweed meal for animal and human consumption. Due to the high level of vitamins and minerals that bioaccumulate in A. nodosum, it has been used in Greenland as a dietary supplement. [6] It was also been used for certain herbal teas, particularly kelp teas.
The prevailing scientific hypothesis is that the transition from non-living to living entities on Earth was not a single event, but a process of increasing complexity involving the formation of a habitable planet, the prebiotic synthesis of organic molecules, molecular self-replication, self-assembly, autocatalysis, and the emergence of cell ...