How is the nervous system characterized, Biology

Assignment Help:

Q. How is the nervous system characterized in beings of the phylum Annelida? How can one compare cephalization in annelids to cephalization in platyhelminthes and nematodes?

Annelids have a nervous system made of two ventral chords and one relatively big nervous cell concentration in its anterior portion resembling a primitive brain.

Nematodes have an anterior neural ring connected to two neural chords, a dorsal one and a ventral, while in planarias (platyhelminthes) there are only two small anterior "cerebral" ganglia from which neural chords split. Cephalization in annelids thus is more outstanding than in flatworms or in nematodes.


Related Discussions:- How is the nervous system characterized

What is the second polar body, Q. What is the second polar body? After ...

Q. What is the second polar body? After termination of the second meiotic division of the oocyte II two cells are generated: the second polar body and the egg cell proper. The

Poisoning, Poisoning: Poisoning  is a common medical emergency  in chi...

Poisoning: Poisoning  is a common medical emergency  in childhood. In children under 5 years of  age essentially all poisoning are accidental. Nearly 75 per  cent  of  all poi

Explain hepatitis c, Hepatitis C It provides sustained viral responses ...

Hepatitis C It provides sustained viral responses (SVRs) of 54% to 63%. When used as monotherapy, peginterferons once weekly are more effective than standard interferon 3 times

Investigation of tricuspid stenosis by echocardiography, Q. Investigation o...

Q. Investigation of Tricuspid stenosis by Echocardiography? Findings are subtle. One should carefully search for organic tricuspid valve involvement in all rheumatic heart dise

Pollen stigma interaction - stigma, Pollen Stigma Interaction - Stigma ...

Pollen Stigma Interaction - Stigma The Stigma After landing on the stigma pollen grain germinates, and produces a pollen tube that carries the male gametes. The stigma has bee

Define safety points that should used in the laboratory, Define Safety poin...

Define Safety points that should used in the Laboratory? You should be aware of the rules/regulations and the procedures before undertaking any practical work in the laboratory

Explain colloidal state, Explain colloidal state Foods contain a high ...

Explain colloidal state Foods contain a high percentage of water in which other nutrients present are dispersed. The existence of the colloidal state was first recognized by T

Explain the categories of fats and oils, Categories of Fats and Oils Yo...

Categories of Fats and Oils You already know that fatty acids are the lipid-building blocks. It is customary to divide  the fatty acids into different groups, e.g.,  saturated

How is the early diagnosis of genetic diseases usually done, How is the ear...

How is the early diagnosis of genetic diseases usually done? The Genetic disease may be diagnosed in the prenatal period by karyotype analysis, in case of aneuploidies, or by D

Explain the lamarcks theory in evolution, Explain the Lamarck's Theory in e...

Explain the Lamarck's Theory in evolution? Prior to Darwin, most people believed in and held to the creationist viewpoint that species were created in their current forms, whic

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd