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

Excretion, Normal 0 false false false EN-IN X-NONE ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What is the expression of moisture content, What is the Expression of Moist...

What is the Expression of Moisture Content? Moisture content, you would realize, is expressed in one of two ways i.e dry weight basis (dwb) or wet weight bases (wwb). Moisture

What is isq, What is ISQ In resonance frequency analysis implant stabil...

What is ISQ In resonance frequency analysis implant stability quotient (ISQ) is use to quantify the frequency measurement of implants within a range between 3500 and 8500 HZ. I

Monocotyledonous embryo, Monocotyledonous Embryo The early developmen...

Monocotyledonous Embryo The early development of the proembryo in monocots follows the same pattern as in the dicots. However, at the time of differentiation in the globular

26 The Human Impact on the Environment, What are the principal sources of e...

What are the principal sources of excessive nitrate and phosphate in rivers and lakes?

Define symptoms in stomach and mouth of pernicious anaemia, Define symptoms...

Define symptoms in Stomach and Mouth of pernicious anaemia? Stomach: The cells which secrete acid and enzymes are atrophied. The gastric secretions are devoid of acid, pepsin

What is reflexive memory, What is reflexive memory? Reflexive memory re...

What is reflexive memory? Reflexive memory relies on the cerebellum and amygdala. Compare among aerobic respiration and anaerobic respiration. Aerobic respiration happens in th

What do you mean by tubular secretion, Q. What is tubular secretion? What a...

Q. What is tubular secretion? What are some examples of substances secreted through the renal tubules? Uric acid, Ammonia, potassium bicarbonate and hydrogen ions, bases and me

Bovine ephemeral fever, Bovine ephemeral fever Ephemeral fever is commonly...

Bovine ephemeral fever Ephemeral fever is commonly known as 'three-day sickness'. It affects mainly cattle and occasionally sheep in India. Causative agent is a mosquito-borne vir

Secretion of hormones, Secretion of Hormones The secretion of most hor...

Secretion of Hormones The secretion of most hormones (except steroid) is by the process of exocytosis. Figure summarises the formation, transport, release and reconstitution o

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