A group of researchers procured some fish like animals and upon investigation the following characters were observed: A. Endoskeleton was made of cartilage. B. Ectoparasitic; as they were found attached on fish skin with their circular sucking mouth. C. Paired fins and scales were absent, but 7 pairs of gill slits were present. Which of the following species of animals did they consider to fit best with these characters?

Core Logic

Let's identify the scientific names from Class Aves:

• Neophron is a vulture (capable of flight).
• Psittacula is a parrot (capable of flight).
• Struthio is an ostrich. It is a flightless bird, but its forelimbs are small and used for balance while running, not for swimming.
• Aptenodytes is the genus for the Emperor Penguin. Penguins are flightless birds whose forelimbs are structurally modified into flippers (paddle-like) specifically for swimming.

Step 1: Final Conclusion

The bird that matches the description is Aptenodytes.

Pattern Recognition

Bird + Swimming forelimbs = Penguin. Scientific name for Penguin in NCERT = Aptenodytes.

Chapter Mix

Class 11 Biology: Animal Kingdom

Core Logic

Flying fish (Exocoetus) is a marine bony fish. Angel fish (Pterophyllum) and fighting fish (Betta) are aquarium bony fishes, meaning they all belong to Class Osteichthyes. Option 1: Devil fish (Octopus) and cuttlefish (Sepia) are molluscs, Hagfish (Myxine) is a cyclostome. Option 2: Starfish (Asterias) is an echinoderm. Option 4: Saw fish (Pristis) and dog fish (Scoliodon) are cartilaginous fishes (Chondrichthyes).

Pattern Recognition

Identify the common names of strictly bony fishes. Exocoetus, Pterophyllum, and Betta consistently group as Osteichthyes.

Chapter Mix

Class 11 Biology: Animal Kingdom

Core Logic

(A) arrow$\rightarrow$ correct arrow$\rightarrow$ Platyhelminthes have an incomplete digestive system. (B) arrow$\rightarrow$ incorrect arrow$\rightarrow$ Bilateral symmetry is a characteristic feature of larvae of echinoderms. In adult echinoderms, radial symmetry is seen. (C) arrow$\rightarrow$ correct arrow$\rightarrow$ Aschelminthes are characterised by the presence of a pseudocoelom. (D) arrow$\rightarrow$ correct arrow$\rightarrow$ Notochord is persistent throughout life in the Chondrichthyes. (E) arrow$\rightarrow$ incorrect arrow$\rightarrow$ Reptiles are cold-blooded (poikilothermic) organisms and thus, they cannot maintain a constant body temperature.

Step 1: Final Conclusion

Thus, the incorrect statements are (B) and (E) only.

Pattern Recognition

Adult echinoderms = radial (pentamerous). Reptiles = cold-blooded (not constant temp).

Chapter Mix

Class 11 Biology: Animal Kingdom