Question

Which one of the following statements about certain given animals is correct?

• A. Roundworms are pseudocoelomates
• B. Molluscs are acoelomates
• C. Annelids are pseudocoelomates
• D. Flatworms are coelomates

Answer 1

The Correct Option is A

To determine which statement about the given animals is correct, we need to understand the terms 'pseudocoelomates', 'acoelomates', and 'coelomates', as well as the classification of the animals mentioned in the options.

Let's analyze each statement:

1. Roundworms are pseudocoelomates: This statement is true. Roundworms, scientifically known as Nematoda, possess a pseudocoelom. A pseudocoelom is a body cavity that is not entirely lined by mesoderm-derived tissue. It acts as a space for the development and suspension of the internal organs.
2. Molluscs are acoelomates: This statement is false. Molluscs are coelomates, meaning they have a true coelom entirely lined with mesodermal tissue. Examples of molluscs include snails, clams, and squids.
3. Annelids are pseudocoelomates: This statement is false. Annelids, such as earthworms and leeches, are coelomates. They have a true coelomic cavity, again fully lined with mesodermal tissue, allowing complex organ development.
4. Flatworms are coelomates: This is also incorrect. Flatworms, or Platyhelminthes, are acoelomates, meaning they lack a coelom. Their bodies are solid except for a primitive gut.

Based on this analysis, the only correct statement is: Roundworms are pseudocoelomates.

In summary, understanding the classification of body cavities helps in determining how different animals are categorized in biological taxonomy.