Question

Statement I: Branchiostoma and Balanoglossus are bilaterally symmetrical and triploblastic animals.
Statement II: They are exclusively marine and possess notochord.

• A. Both statements I and II are correct and II explains I
• B. Both statements I and II are correct and II does not explain I
• C. Statement I is true and statement II is false
• D. Both statements I and II are false

Answer 1

Answer: (C)

Balanoglossus(Phylum-Hemichordata) and Branchiostcma $(=$ Amphioxus, Subphylum-Cephalochordata) both are bilaterally symmetrical and triploblastic animals. Both are marine animals. Balanoglossus does not possess a notochord whereas Branchiostoma being a chordate possesses notochord that persists throughout life.