Question

Starting with the organism that evolved first, the correct order of evolution of given organisms is

• A. Sponge, flatworm, chordate and mollusk
• B. Flatworm, mollusk, sponge and chordate
• C. Sponge, flatworm, mollusk and chordate
• D. Mollusk, sponge, flatworm and chordate
• E. Flatworm, sponge, chordate and mollusk

Answer 1

Answer: (C)

Sponge, flatworm, mollusk and chordate

Amongst the options given, sponge being a poriferan evolved first. Then came Platyhelminthes, including flatworms, followed by mollusks and then finally chordates. Chordates are the most advanced taxonomic group of animals, that is, they have evolved the most.

So, the correct answer is 'Sponge, flatworm, mollusk, and chordate'.