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

Slim mold, what is the cycle of slime moldand thier structure

what is the cycle of slime moldand thier structure

Define the parathryroid gland, Which of the following serves as an effector...

Which of the following serves as an effector, or part of an effector, that functions in a negative feedback system? A. 1,25-dihydroxyvitamin D Receptors located intracellularly

What property of water helps, South Dakota and Oregon are at similar latitu...

South Dakota and Oregon are at similar latitudes, and yet, on average, Oregon has warmer winters and cooler summers than South Dakota does. What property of water helps account for

What are risk factors for diseases, What are risk factors for diseases? ...

What are risk factors for diseases? Risk factors for a disease are everything that contributes to enhance the risk of the disease to appear. For instance, for most cardiovascul

Centrioles, Centrioles Centrioles is also called cell centre . C...

Centrioles Centrioles is also called cell centre . Centrosome discovered by Benden . T. Boveri called it centrosome. Centrosome is present in all animal eukaryotic

How are amphibians characterized, Q. Amphibian identity card. How are amphi...

Q. Amphibian identity card. How are amphibians characterized according to examples of representing beings, basic morphology, circulation, skin, nitrogen waste, respiration, thermal

Embyonic development, What are the different patterns of cleavage (segmenta...

What are the different patterns of cleavage (segmentation of fertilized egg cell)?

Bone marrow transplant, BON E MARROW TRANSPLANT - It is transplante...

BON E MARROW TRANSPLANT - It is transplanted to treat leukemia. Here, graft itself causes immune rejection. Before transplant, the recipient's bone marrow cells, incl

Explain properties of amylopectin and amylose, Properties of Amylopectin an...

Properties of Amylopectin and Amylose In plants, starch is packaged in granules, which vary in their  shape and size, when isolated from different sources. The size of these gr

How do sponges try to protect themselves, Q. How do sponges try to protect ...

Q. How do sponges try to protect themselves against harm from the environment? Is that method rudimentary or efficient? Sponges can close their pores to avoid the entrance of w

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