Polychaete, mollusca and echinodermata, Biology

Assignment Help:

Polychaete, Mollusca and Echinodermata

Polychaete and Mollusca

The polychaetes have a trochophore larva. A common trochophore larva is top shaped bearing a tuft of cilia at the apical end and a band or girdle of cilia termed as the prototroch which rings the body about one third to one half the distance from the apical tuft. It is the swimming organ and collects suspended food particles. The gut is a complete tube and mouth opens posterior to prototroch. Trochophore larva is characteristic of polychaetes and molluscs.

Echinodermata

Almost all larvae of echinoderms are planktonic. Not like the adults the larvae do not show pentamerous symmetry and do not have tube feet. They move by bands of cilia over the body and its projections. After a time of planktonic life a rudimentary skeleton starts to form and the larvae sink to the bottom to develop the adult shape and form.


Related Discussions:- Polychaete, mollusca and echinodermata

Where are blood cells made in the body, Where are blood cells made in the b...

Where are blood cells made in the body? Blood cells are made in the red bone marrow, e.g. in the ribs, sternum or vertebrae.

State about membrane-spanning molecule, State about membrane-spanning molec...

State about membrane-spanning molecule Neuron A is a healthy neuron with all the usual ion channels and with all the usual intracellular and extracellular distributions of ion

Six kingdom worksheet, what protist changes shape constantly and flows arou...

what protist changes shape constantly and flows around its food to engulf it?

Efficient colors for photosynthesis, Q. What are the main divisions of whit...

Q. What are the main divisions of white light according to the electromagnetic spectrum? Which are the two mainly efficient colors for photosynthesis? The color divisions of th

Give brief description about the generalised seizures, Generalised Seizures...

Generalised Seizures Generalised seizures are bilaterally symmetrical without focal onset. One subtype, the grand mal attack, is characterised by loss of consciousness and by s

Photosynthesis., what carbohydrates does a plant make from glucose

what carbohydrates does a plant make from glucose

Eliminate heat energy at the rate of approximately, A large leaf on a plant...

A large leaf on a plant in bright sunshine evaporates 5 grams of water per hour. Cooling the leaf through evaporation in this manner enables the plant to eliminate heat energy at t

Cnidaria and platyhelminthes - larval forms, Cnidaria and Platyhelminthes -...

Cnidaria and Platyhelminthes - Larval forms Cnidaria The common larval stage that is found in cnidarians is the planula which forms following gastrulation. The planula is

Special characteristic of stem cells, What is the special characteristic of...

What is the special characteristic of (a) stem cells, (b) embryonic stem cells? (a) Stem cells can continue to divide throughout their life. (b)The special characteristic of

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