
Assertion (A): During pulmonary respiration in frog, buccopharyngeal cavity acts like a force pump.
Reason (R): When the floor of buccopharyigeal cavity is lowered, air forces the glottis to open and reach the lungs.
The correct option among the following is:


Important Questions on Phylum Chordata

Statement I: Sternum appeared for the first time in amphibians.
Statement II: Snakes have pairs of cranial nerves.
The correct option among the following is


Statement Chordates have a tail extending posterior to the anus. It contains skeletal elements and muscles but lacks coelom and visceral organs.
Reason In aquatic organisms, it acts as a balancing organ.

Which of the key adaptations helped evolutionary success of Reptiles on land?
A Warm-bloodedness
B. Pulmonary respiration and dry scaly skin
C. Internal fertilisation
D. Amniotic & Cleidoic eggs

Statement (S) : The amphibian blood is composed of erythrocytes, leucocytes and thrombocytes. The thrombocytes help in haemostasis.
Reason (R): The haemostasis regulates the body temperature in poikilotherms.
Which of the following is true?

Match the following
List - I | List - II | ||
(a) | Chelonia | (i) | Alligator |
(b) | Rhynchocephalia | (ii) | Chameleon |
(c) | Crocodilia | (iii) | Sphenodon |
(d) | Squamata | (iv) | Testudo |
The correct answer is

Match the following
List - I | List - II | ||
(a) | Each half of the lower jaw is formed by 6 bones | (i) | Aves |
(b) | Lacrimal and Harderian glands appeared for the first time | (ii) | Reptiles |
(c) | Presence of only right systemic arch | (iii) | Amphibians |
(d) | Each half of the lower jaw is made of single bone | (iv) | Mammals |
