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Strobilation or transverse fission is a form of asexual reproduction consisting of the spontaneous transverse segmentation of the body. It is observed in certain cnidarians and helminths . This mode of reproduction is characterized by high offspring output, which, in the case of the parasitic tapeworms, is of great significance.
Binary fission in organisms can occur in four ways: irregular, longitudinal, transverse, or oblique. For example: For example: Irregular: In this fission, cytokinesis may take place along any plane but it is always perpendicular to the plane of karyokinesis (nuclear division). e.g. Amoeba .
E. lineata has a simple internal structure and is unusual among sea anemones in that it can divide by transverse fission. [5] This type of asexual reproduction can be achieved through either physal pinching or polarity reversal.
They also produce gemmae, for example in the splash-cups of Marchantia polymorpha, [3] that are easily broken off and distributed. People use fragmentation to artificially propagate many plants via division , layering , cuttings , grafting , micropropagation and storage organs , such as bulbs , corms , tubers and rhizomes .
Sea anemones have great powers of regeneration and can reproduce asexually, by budding, fragmentation, or longitudinal or transverse binary fission. Some species such as certain Anthopleura divide longitudinally, pulling themselves apart, resulting in groups of individuals with identical colouring and markings. [11]
The nuclei are evenly distributed. The animal reproduces by longitudinal and transverse binary fission, or by plasmotomy in which the cell division is repeated again and again without division of nuclei. The daughter cells encysted and pass out in the faecal matter of the host. An example of a species is Opalina ranarum. [2]
(c) Enlargement of the area in (b) showing two cyanobionts that are being divided by binary transverse fission (white arrows). Heterotrophic dinoflagellates can form symbioses with cyanobacteria (phaeosomes), most often in tropical marine environments. [12] The function of the cyanobiont depends on its host species.
For example, the up quark has T 3 = + + 1 / 2 and the down quark has T 3 = − + 1 / 2 . A quark never decays through the weak interaction into a quark of the same T 3: Quarks with a T 3 of + + 1 / 2 only decay into quarks with a T 3 of − + 1 / 2 and conversely. π + decay through the weak interaction