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

Assume complete absorption, How many pints (473 ml) of Fat Tire amber ale c...

How many pints (473 ml) of Fat Tire amber ale can an 80 kg person drink in Arizona before reaching the blood alcohol limit? Fat Tire's ethanol concentration of 5.3% (v/v). Assume c

Components of treatment of nkhdc, The components of treatment of NKHDC are:...

The components of treatment of NKHDC are: 1) control of water loss. 2) control of sugar using insulin. 3) adjust electrolytes like sodium and potassium. 4) control infe

Types of sperm, TYPES OF SPERM Mainly two types . (1) Flagellated Sp...

TYPES OF SPERM Mainly two types . (1) Flagellated Sperm - Generally all sperm are monoflagelated, but in todfish or opsonus sperm is biflagelated. (2) Non flagellated spe

Quality control of feedstuffs, Quality control of feedstuffs Quality co...

Quality control of feedstuffs Quality control is essential at all stages in the production of compound feed so that animals could get wholesome balanced and nutritious feed. Th

Mammalian lungs - respiration, Mammalian Lungs - Respiration In this w...

Mammalian Lungs - Respiration In this we will study mainly mammalian lungs as it is the best representative of a respiratory surface adapted for terrestrial respiration. For t

What is the importance of vitamin B2, What is the Importance of vitamin b2 ...

What is the Importance of vitamin b2 As a prosthetic group of the flavin enzymes, vitamin B 2 is involved in the reactions of almost all nutrients of plants and animals. They

glycolysis, explain glycolysis briefly? elaborat

explain glycolysis briefly? elaborate

How an electron acceptor becomes nadh, If NAD+ is an electron acceptor that...

If NAD+ is an electron acceptor that becomes NADH and the NADH then donates a proton to ATPase, shouldn't NADH now become NAD- since it lost it's proton but still has the electron?

How inadequate breast milk cause protein energy malnutrition, How Inadequat...

How Inadequate Breast Milk cause protein energy malnutrition? Though prolonged breastfeeding of children is the rule in US, the amount of breast milk secreted in poor Indian mo

Phototherapy unit, Phototherapy Unit Principle Photoisomerisat...

Phototherapy Unit Principle Photoisomerisation and photo-oxidation changes indirect bilirubin into water soluble substance. Operational Instruction Adjust

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