
Metatherian mammals are viviparous animals.

Important Questions on Classification of Living Organisms
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 |

a) Chondrichthyes have gill slits covered by operculum and Osteichthyes have gill slits without operculum
b) Chondrichthyes have a swim bladder and Osteichthyes do not have a swim bladder
c) Chondrichthyes contain placoid scales and Osteichthyes contain cycloid scales
d) Chondrichthyes contain terminal mouth and Osteichthyes contain ventral mouth

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



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

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




Study the following table
Group | Feature | Example | |
Cyclostomata | Renal portal system is absent | Branchiostoma | |
Reptilia | Megalecithal and cleidoic eggs | Tropidonotus | |
Aves | Corpora quadrigemina | Psittacula | |
Amphibia | Columella auris in middle ear | Rhacophorus |
Identify the correct combinations



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?


Name the classes of Tetrapoda that exhibit the following characters:
Column (A) | Column (B) |
Acrodont | Thecodont |
pairs cranial nerves | pairs cranial nerves |
Cold-blooded | Warm-blooded |
Amphicoelous vertebrae | Amphiplatyan vertebrae |




Animals Morphological features
(i) Crocodile - 4-chambered heart
(ii) Sea urchin - Parapodia
(iii) Obelia - Metagenesis
(iv) Lemur - Thecodont

