Question

What are differences between the following:
(a) Cartilaginous fishes and bony fishes;
(b) Amphibia and Reptilia.

Answer 1

(a) Cartilaginous fishes vs Bony fishes:

Cartilaginous fishes	Bony fishes
(i) They have a cartilaginous endoskeleton.	(i) They have a bony endoskeleton.
(ii) They contain five to seven pairs of gill slits.	(ii) They contain four pairs of gill slits.
(iii) Their mouth is ventral in position.	(iii) Their mouth is terminal in position.
(iv) Swim bladder is absent in them.	(iv) Air bladder is usually present in them.

(b) Amphibia vs Reptilia:

Amphibia	Reptilia
(i) Their skin is glandular, smooth and moist.	(i) Their skin is non-glandular, dry and keratinized.
(ii) Scales are not present in them.	(ii) Horny scales are present over their body.
(iii) They have a three chambered heart.	(iii) Their heart is incompletely four chambered.
(iv) Fertilisation is external.	(iv) Fertilisation is internal.