2020 · Q14
In which of the following phylum, would you place an animal with a bilaterally symmetrical, triploblastic body without a true internal cavity (coelom)?
general-sciencebiology-human-body
- APorifera
- BPlatyhelminthes
- CCnidaria
- DAnnelida
Explanation
Platyhelminthes (flatworms) are bilaterally symmetrical, triploblastic and acoelomate — they have no true internal body cavity. Porifera are mostly asymmetrical and diploblastic, Cnidaria are radially symmetrical and diploblastic, and Annelida possess a true coelom. Only the flatworms match the full description.