Problem of polarity in regeneration in planarians, Biology

Problem of Polarity in Regeneration in Planarians

As in Hydra, flatworm regeneration as well appears to occur in a polar fashion. There seems to be ananterior-posterior gradient system as the cut anterior surface will make a head and the cut posterior surface will form a head. As in Hydra, middle pieces are able of regenerating both a head and a tail. Identical to the Hydra there is an exception to this rule, for if the middle piece is too thin as compared to the planarian segment will grow two heads.

It is believed that the anterior-posterior gradient is not efficiently delineated in such a small segment and that the piece cannot determine "Which end is up", as neither end of the segment has an advantage over the other. Evidence exists that the polarity gradient is due to metabolic activity and that the much more metabolically active end makes the head. Two-headed flatworms are so produced by removing anterior posterior metabolic gradient. It has also been observed that flatworms in addition to retaining anterior-posterior polarity can also regenerate the missing half if split longitudinally. It is believed that the pattern of planaria regeneration is similar to hydra as it also controlled by diffusible gradients.

Posted Date: 1/31/2013 5:49:40 AM | Location : United States







Related Discussions:- Problem of polarity in regeneration in planarians, Assignment Help, Ask Question on Problem of polarity in regeneration in planarians, Get Answer, Expert's Help, Problem of polarity in regeneration in planarians Discussions

Write discussion on Problem of polarity in regeneration in planarians
Your posts are moderated
Related Questions
From the following, name the type of mimicry by which a palatable, acceptable insect mimics an unfavorable, noxious insec for protection. a) Batesian mimicry (pron: BATE-see-an

Q. What is the defense mechanism that begins to work when inflammation fails to stop an infection? If the inflammatory attack is not sufficient to halt the infectious process t

bloodpressure will be more in _ in than in_

when pollen tube enters the embryo-sac,it has;


Which is the kind of gamete produced by a heterozygous individual? And what is the genotypical proportion of these gametes? The Heterozygous individuals, for instance, AA, prod

Q. As a result of the DNA replication two DNA molecules come into existence. Why is it not correct to assert that the two "new" DNA molecules are created? What is the name given to

What is the difference between spermatids and sperm cells? What is the name of the transformation of spermatids into sperm cells? Sperm cells (the male gametes) are matured spe

Q. Causes of oesophagitis? The causes include tissue erosion by hydrocliloric acid (EIC1) and pepsin, with symptoms of substernal burning, cramping, pressure sensation or sever

Pathophysiology   Insufficient  amount of iron present in the body leads  to reduction in serum transferrin (Serum betaglobulin, which binds and transports iron) saturation.  T