निम्नलिखित में से किसे छोड़कर अन्य सभी में संगठन का अंग-तंत्र स्तर (organ system level of organisation) देखा जाता है?

Select the incorrect statements from the following: A. Digestive system in Platyhelminthes is incomplete. B. Bilateral symmetry is a characteristic feature of adult Echinoderms. C. Pseudocoelom is possessed by Aschelminthes. D. Notochord is persistent throughout life in the class Chondrichthyes. E. Members of class Reptilia maintain a constant body temperature. Choose the correct answer from the options given below:

Select the set of fishes that belong to the class Osteichthyes:

The flightless bird with forelimbs modified into paddle-like structures suited for swimming is known as:

A group of researchers observed the following characters in a fish-like animal: A. Endoskeleton made of cartilage. B. Ectoparasitic, attached to fish skin with a circular sucking mouth. C. Paired fins and scales were absent, but gill slits were present. Which of the following animals fits best with these characters?

Euplectella belongs to which phylum/group of the animal kingdom?

Which of the following organisms belongs to Phylum Hemichordata and exhibits a stomochord (rudimentary structure similar to a notochord)?

In which subphylum of chordates is the notochord present only in the tail region of the larval stage?

How does the notochord differ between Urochordata and Cephalochordata?