Excretion in non-chordates, Biology

Assignment Help:

Excretion in Non-Chordates

Excretion as described under Introduction of this unit refers to removal of the waste products of metabolism - carbon dioxide (CO2) and water released by the oxidation of energy rich compounds and the nitrogenous wastes released through the metabolism of proteins and nucleic acids. Though, we will here limit ourselves to elimination of nitrogenous waste. In small ones, particularly aquatic ones, simple diffusion from body surface plays a significant role in elimination of nitrogenous wastes. Even in larger aquatic animals some diffusion occurs from body surface, but they have evolved specialised organs for excretion, which play the main role in elimination of nitrogenous waste material. However, it has to be remembered, that many of these organs serve basically osmoregulatory function rather than excretory. Well described excretory organs are seen from the pseudocoelomate animals onwards. Several groups of metazoans have nephridia as excretory organs. A nephridium develops from the ectoderm centripetally. The lumen of the nephridium is formed by using the hollowing out of nephridial cells. Thus nephridia are intracellular. In primitive animals this lumen is closed internally but subsequently attains an opening into the coelom. The opening is termed as nephridial funnel or nephrostome. Its opening to the outside is by nephridiopore.


Related Discussions:- Excretion in non-chordates

Explain the fistulative surgery - endodontic surgery, Explain the Fistulati...

Explain the Fistulative surgery - Endodontic Surgery = (Incision and drainage) 1 Cortical trephination 2 Decompression 3

Main prophylactic measures against schistosomiasis, What are the main proph...

What are the main prophylactic measures against schistosomiasis? The main measures to stop schistosomiasis are: information for infected individuals to look for treatment and t

Explain tetralogy of fallot repair and transposition, Explain Tetralogy of ...

Explain Tetralogy of fallot repair and Transposition of arteries? Tetralogy of Fallot Repair: This involves RV outflow resection, closure of the VSD and enlargement of the RV

What is insulin pump, Insulin Pump An  insulin pump is a device used fo...

Insulin Pump An  insulin pump is a device used for the administration of  insulin, also known as continuous subcutaneous insulin infusion therapy. The device includes: - the

Synovial fluid and amniotic fluid collection, Synovial fluid Collection: ...

Synovial fluid Collection: The technique of obtaining synovial fluid is called arthrocentesis. It is used to characterize type of arthritis and to differentiate inflammatory

How vaginal infections cause, How Vaginal infections cause Sulfonamide ...

How Vaginal infections cause Sulfonamide creams, other ''broad-spectrum'' vaginal preparations, and currently available preparations of Lactobacillus  species or dairy products

What is the form that produces gametes, In the metagenesis of Aurelia and O...

In the metagenesis of Aurelia and Obelia what is the form that produces gametes? What is the form that reproduces asexually? In the metagenesis of some coelenterates, like Obel

Eucaryotic cell structure , Eucaryotic cell structure All eucaryotic c...

Eucaryotic cell structure All eucaryotic cells have a cytoskeleton made up of a network of protein filaments (Figure shown below). This network gives the cell its shape, capac

Procedures for diagnosis - nucleic acid hybridization, Nucleic acid hybridi...

Nucleic acid hybridization: This is a process by which a suitably labeled DNA or RNA from a known infectious agent is used to probe its complementary sequence unique to t

Mitral valve replacement, Mitral Valve Replacement :  When mitral...

Mitral Valve Replacement :  When mitral valve replacement for a calcified, stenotic valve is done, usually it is a classical procedure removing leaflets, their chordae an

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