Question

From the features given below, identify the phylum A, B, C with the example.

$\begin{array}{ccc}\text{A}& \text{B}& \text{C}\\ \text{Bilaterally symmetrical}& \text{Bilaterally symmetrical}& \text{Bilaterally symmetrical}\\ \text{Pseudocoelomate}& \text{Open circulatory system}& \text{Marine animals}\\ \text{Parasitic worms}& \text{Reduced coelomic cavity}& \text{Notochord}\end{array}$

• A. A- Nematoda- Planaria
  B- Arthropoda- Prawns
  C- Vertebrata- Herdmania
• B. A- Nematoda- Filarial worm
  B- Mollusca- Mussels
  C- Protochordata- Amphioxus
• C. A- Platyhelminthes- Liverfluke
  B- Mollusca- Mussels
  C- Protochordata- Amphioxus
• D. A- Platyhelminthes- Tapeworm
  B- Arthropoda- Prawns
  C- Vertebrata- Herdmania

Answer 1

The correct option is B A- Nematoda- Filarial worm

B- Mollusca- Mussels
C- Protochordata- Amphioxus
$\bullet$ Organisms belonging to phylum Nematoda are bilaterally symmetrical. Their body cavity is called pseudocoelom. Since the mesoderm is found as scattered pouches in between the ectoderm and the endoderm. They are parasitic worms and are responsible for causing diseases like elephantiasis (filarial worms).
​​​​​​​$\bullet$ Molluscs are bilaterally symmetrical and have an open circulatory system, like arthropods. But, molluscs have a reduced coelomic cavity. E.g., Mussels, snails.
​​​​​​​$\bullet$ Protochordates are exclusively marine animals. They are bilaterally symmetrical and possess notochord at some stages of their lives. E.g., Amphioxus, Herdmania, balanoglossus, etc.