
In which phylum are the pseudocoelomates animals placed?
Answer
425.4k+ views
Hint: The body cavity of the organisms is lined by a layer of cells called mesoderm. This body cavity is called a coelom. This term coelom is coined by the scientist “Haekel”. To be more elaborate, The space between the body wall of organisms and the visceral organs is filled with fluid. This space is called Coelom.
Complete Answer:
The organisms are classified into various types based on the different types of coelom.
They are:
1. Acoelomates
2. Eucoelomates
3. Pseudocoelomates
1. Acoelomates: They do not contain any body cavity hence the organisms having no coelom are called Acoelomates. Example : Platyhelminthes
2. Eucoelomates: They contain a true body cavity filled with fluid lined by mesoderm epithelial cells. Hence the organisms containing true coelom are defined as acoelomates.
Examples: annelida, Mollusca etc.
3. Pseudocoelomates:
They contain the body cavity filled with fluid but they are not lined by the mesodermal epithelial cells. Hence, it is considered a false coelom and the organisms are called pseudocoelomates.
Examples: Aschleminthes - Nematoda, rotifera.
Hence, The phylum under which the pseudocoelomates are placed is Nematoda/Aschelminthes.
Phylum nematoda consists of two classes, namely Aphasmidia, example: Trichinella and Phasmidia, examples Ascaris.
Note:
Pseudocoelom is considered as the false body cavity. Tube within tube organization in organisms started with pseudocoelomates only. It functions as normal coelom only but some muscular movements of organs present internally may be restricted. It also acts as a shock absorber which means it protects organs inside from any external force.
Complete Answer:
The organisms are classified into various types based on the different types of coelom.
They are:
1. Acoelomates
2. Eucoelomates
3. Pseudocoelomates
1. Acoelomates: They do not contain any body cavity hence the organisms having no coelom are called Acoelomates. Example : Platyhelminthes
2. Eucoelomates: They contain a true body cavity filled with fluid lined by mesoderm epithelial cells. Hence the organisms containing true coelom are defined as acoelomates.
Examples: annelida, Mollusca etc.
3. Pseudocoelomates:
They contain the body cavity filled with fluid but they are not lined by the mesodermal epithelial cells. Hence, it is considered a false coelom and the organisms are called pseudocoelomates.
Examples: Aschleminthes - Nematoda, rotifera.
Hence, The phylum under which the pseudocoelomates are placed is Nematoda/Aschelminthes.
Phylum nematoda consists of two classes, namely Aphasmidia, example: Trichinella and Phasmidia, examples Ascaris.

Note:
Pseudocoelom is considered as the false body cavity. Tube within tube organization in organisms started with pseudocoelomates only. It functions as normal coelom only but some muscular movements of organs present internally may be restricted. It also acts as a shock absorber which means it protects organs inside from any external force.
Latest Vedantu courses for you
Grade 11 Science PCM | CBSE | SCHOOL | English
CBSE (2025-26)
School Full course for CBSE students
₹41,848 per year
Recently Updated Pages
Master Class 11 Economics: Engaging Questions & Answers for Success

Master Class 11 Business Studies: Engaging Questions & Answers for Success

Master Class 11 Accountancy: Engaging Questions & Answers for Success

Master Class 11 English: Engaging Questions & Answers for Success

Master Class 11 Computer Science: Engaging Questions & Answers for Success

Master Class 11 Maths: Engaging Questions & Answers for Success

Trending doubts
State and prove Bernoullis theorem class 11 physics CBSE

What are Quantum numbers Explain the quantum number class 11 chemistry CBSE

Write the differences between monocot plants and dicot class 11 biology CBSE

Who built the Grand Trunk Road AChandragupta Maurya class 11 social science CBSE

1 ton equals to A 100 kg B 1000 kg C 10 kg D 10000 class 11 physics CBSE

State the laws of reflection of light
