Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
Choose the correct statements:

I. Cartilaginous fish swims continuously due to the presence of an air bladder.
II. Osteichthyes have four pairs of gills that are covered by an operculum.
III. The notochord is persistent throughout life in Chondrichthyes.
IV. Teeth of cartilaginous fishes are modified placoid scales.
BiologyAnimal KingdomNEET
Options:
  • A Only (I) & (II) are correct
  • B Only (II), (III) & (IV) are correct
  • C Only (II) & (IV) are correct
  • D All are correct
Solution:
2203 Upvotes Verified Answer
The correct answer is: Only (II), (III) & (IV) are correct
Due to absence of air bladder in cartilaginous fishes, they have to swim constantly to avoid sinking. They have usually five pairs of gill slits which are separate and are without operculum.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.