Question

Consider the following statements (A-D) each with one or two blanks

A. Four characters of chordates are the presence of (i)______ , dorsal hollow nervous system, (ii)_____ and muscular tail.
B. Agnatha are the most primitive craniates They are commonly called (iii)______ vertebrates.
C. Electric ray belongs to Class (iv)_____ while sea horse belongs to dass (v)____.
D. (vi)_____ are also defined as feathered bipeds. These have a (vii)_____ gland on the tail.
Which one of the following options, correctly fills any two of the given statements?

• A. (iii)- jawless, (iv)- Osteichthyes, (v)- Chondrichthyes
• B. (i)- notochord, (ii)- pharyngeal gill slits, (iv)- Chondrichthyes, (v)- Osteichthyes
• C. (iii)- jawed, (vi)- Reptiles, (vii)- uropygial
• D. (i)- four-chambered heart, (ii)- Pharyngeal gill slits, (vi)-Birds, (vii)- uropygial

Answer 1

The correct option is B (i)- notochord, (ii)- pharyngeal gill slits, (iv)- Chondrichthyes, (v)- Osteichthyes

A. (i) notochord, (ii) pharyngeal gill slits

B. (iii) jawless

C. (iv) Chondrichthyes, (v) Osteichthyes

D. (vi) Aves, (vii) uropygial

So, the correct answer is (b).