Classification of multicellular animals - coelom, Biology

Assignment Help:

Classification of Multicellular Animals - Coelom

We know earlier that the pseudocoel gave animals specific selective benefits. Among other things, this fluid-tilled space worked as a hydrostatic skeleton increasing the efficiency of burrowing. However, in pseudocoelomates, organs lay loose in the body cavity. To circumvent this drawback, coelom evolved within mesoderm. The result was that the new body cavity, that is the coelom, came to be lined by mesodermal layer (peritoneal layer). The various organs also came to be suspended in the coelom through the mesodermal layer called mesenteries. This enabled the body wall to become much more muscular, with better developed longitudinal and circular muscles. The body cavity so became a more efficient hydrostatic skeleton now. The alimentary canal also became more muscular and more specialised. Various organs became better arranged in a much more stable way, without interfering with one another. The mesenteries as well served as a better medium for positioning blood vessels to the respective organs. So, development of coelom has been a main step in the evolution of more complex and larger animals.


Related Discussions:- Classification of multicellular animals - coelom

What are the uses of squid fins, What are the uses of squid fins? Fins ...

What are the uses of squid fins? Fins are used by squids to move at low speeds. Their siphon is used when they require moving quickly.

Define hocm murmur characteristics in details, Define HOCM Murmur character...

Define HOCM Murmur characteristics in details? Characteristics: The murmur is harsh, crescendo-decrescendo audible along the left sternal border, radiates to the base of heart

Types of forests - ecosystem, Types of Forests - Ecosystem The forest ...

Types of Forests - Ecosystem The forest biomes of the world have been classified into the three major categories: coniferous forest, tropical forest and temperate forest. C

What are allele frequencies, You observe the following numbers of individua...

You observe the following numbers of individuals of each genotype in a population. AA=700, Aa=200, aa=100. What are the observed genotype frequencies in this population? What are t

Explain in detail about soil micromorphology, Explain in detail about soil ...

Explain in detail about soil micromorphology A good examination with optical aid reveals more detailed features which are helpful in understanding pedogenesis. This is known as

Excretion in amoeba, EXCRETIO N IN AMOEBA - NH 3  is excreted out t...

EXCRETIO N IN AMOEBA - NH 3  is excreted out through plasmalemma. Osmoregulation takes place by contractile vacoule, generally one, towards posterior end, contractile in

Agrostology, Agrostology : This is related to all types of grasses. Agrosto...

Agrostology : This is related to all types of grasses. Agrostology is sometimes called as graminology. Agrostology is the scientific study of grasses. It typically encompasses the

Define the osazone test or phenylhydrazine reaction, Define the Osazone Tes...

Define the Osazone Test or Phenylhydrazine Reaction? Compounds with -CO-CHOH group form crystalline osazones with phenyl hydrazine. These osazones have characteristic shapes an

Define cerebral hemisphere tissue, Q. Define cerebral hemisphere tissue? ...

Q. Define cerebral hemisphere tissue? CEREBRAL WHITE MATTER - The remaining cerebral hemisphere tissue is the deeper cerebral white matter (60% of cerebral volume) which includ

Chemical properties of soil, CHEMICAL PROPERTIES OF SOIL Soil is a high...

CHEMICAL PROPERTIES OF SOIL Soil is a highly dynamic system which supports complex chemical reactions. In this heterogeneous systems, the soil solution acts as the medium for c

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