Question

Consider the following statements :
A. Annelids are true coelomates
B. Poriferans are pseudocoelomates
C. Aschelminthes are acoelomates
D. Platyhelminthes are pseudocoelomates
Choose the correct answer from the options given below :

• A. B only
• B. A only
• C. C only
• D. D only

Answer 1

The Correct Option is B

To assess the veracity of the statements regarding the body cavity types in different animal phyla, we need to understand the definitions of terms such as "true coelomates," "pseudocoelomates," and "acoelomates." Let's evaluate each statement:

• A. Annelids are true coelomates: This statement is correct. Annelids, such as earthworms, have a coelom, which is a fluid-filled body cavity fully lined by mesoderm tissue.
• B. Poriferans are pseudocoelomates: This statement is incorrect. Poriferans, commonly known as sponges, lack any true body cavity and are considered asymmetrical organisms without defined digestive systems.
• C. Aschelminthes are acoelomates: This statement is incorrect. Aschelminthes, or Nematodes, are pseudocoelomates, meaning they have a body cavity not entirely lined by mesoderm.
• D. Platyhelminthes are pseudocoelomates: This statement is incorrect. Platyhelminthes, or flatworms, are acoelomates, meaning they have no body cavity between their digestive tract and body wall.

Thus, only statement A is correct, making option "A only" the right choice.

Answer 2

Coelom Classification of Different Phyla:

• A. Annelids – True coelomates, having a well-developed coelom.
• B. Poriferans – Not pseudocoelomates; they lack a true coelom.
• C. Aschelminthes – Pseudocoelomates, not acoelomates.
• D. Platyhelminthes – Acoelomates, not pseudocoelomates.

Thus, the correct answer is (2) A only.