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

Cartilage occur in a joint and what it its function, Where does cartilage o...

Where does cartilage occur in a joint and what it its function? Cartilage might be found covering the surface of bones where they meet in a movable joint. Cartilage decreases f

Illustrate the applications of gellan gum, Illustrate the Applications of G...

Illustrate the Applications of Gellan gum Gellan is a highly versatile food ingredient and has numerous applications in foods. The combination of gelatin with gellan, by compar

Explain the basic concept of adulteration, Explain the Basic Concept of Adu...

Explain the Basic Concept of Adulteration? Food adulteration is the change in original composition and quality of food by adding, removing or substituting some ingredients of f

Can you explain likar system with electrodes, Q. Can you explain Likar Syst...

Q. Can you explain Likar System with Electrodes? The 12 lead Mason - Likar system with electrodes is used. The plastic adhesive electrodes has self contained electrode jelly in

Define food science as a discipline and modern developments, Define Food Sc...

Define Food Science as a Discipline and Modern Developments? As an undergraduate student you may have taken a course in food science and technology. Do you recall, what did the

Explain the energy flow of ecology, Explain the energy flow of ecology? ...

Explain the energy flow of ecology? Energy flow: As you can see, energy flow is one way in an ecosystem. Energy is not recycled. The ultimate source of energy that powers eco

Theskin, drawandlabelthemajorendocrineglandsofthehumanbody

drawandlabelthemajorendocrineglandsofthehumanbody

How does the male gamete penetrate the egg cell, Q. How does the male gamet...

Q. How does the male gamete penetrate the egg cell? How does the female gamete protect itself from the entrance of more gametes after the entrance of the first sperm cell? The

Mr, Define animals

Define animals

Testing a leaf for statch, State four steps to be followed to test for star...

State four steps to be followed to test for starch in a leaf

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