Which one of the following statements about certain given animals is correct?
- Roundworms (Aschelminthes) are pseudocoelomates
- Molluscs are acoelomates
- Insects are pseudocoelomates
- Flatworms (Platyhelminthes) are coelomates
Answer
(1) Roundworms (Aschelminthes) are pseudocoelomates
Solution
As per NCERT, in some animals the body cavity is not lined by mesoderm; instead, mesoderm is present as scattered pouches between ectoderm and endoderm — such animals are pseudocoelomates, e.g., aschelminthes.
∵ Molluscs and insects (arthropods) are coelomates ⇒ (2) and (3) are wrong.
∵ Flatworms are acoelomates ⇒ (4) is wrong.
Answer: (1)