Question

Match the following column I and column II and choose the correct option.

	Column-I		Column-II
a.	Placoid scales	(i)	Trygon
b.	Operculated gills	(ii)	Pristis
c.	Ectoparasites on some fishes	(iii)	Exocoetus
d.	Sting ray	(iv)	Petromyzon

• A. a - ii, b - iii, c - iv, d - i
• B. a - iii, b - iv, c - i, d - ii
• C. a - iv, b - ii, c - iii, d - i
• D. a - i, b - iv, c - iii, d - ii

Answer 1

The correct option is A a - ii, b - iii, c - iv, d - i

Placoid scales are present in cartilaginous fishes such as saw fish (Pristis).
Exocoetus is a bony fish while Petromyzon is a cyclostome.