Question

Classify the following based on the number of chambers in their hearts.
Rohu, Scoliodon, Frog, Salamander, Flying lizard, King cobra, Crocodile, Ostrich, Pigeon, Bat, Whale
a) (i) Two-chambered heart: Frog, Salamander
(ii) Three-chambered heart: Rohu, Scoliodon
(iii) Incomplete four-chambered heart: Flying lizard, King cobra
(iv) Complete four-chambered heart: Crocodile, Ostrich, Pigeon, Bat, Whale
b) (i) Two-chambered heart: Rohu, Scoliodon
(ii) Three-chambered heart: Frog, Salamander
(iii) Incomplete four-chambered heart: Flying lizard, King cobra
(iv) Complete four-chambered heart: Crocodile, Ostrich, Pigeon, Bat, Whale
c) (i) Two-chambered heart: Frog, Salamander
(ii) Three-chambered heart: Rohu, Scoliodon
(iii) Incomplete four-chambered heart: Crocodile, Ostrich, Pigeon, Bat, Whale
(iv) Complete four-chambered heart: Flying lizard, King cobra
d) (i) Two-chambered heart: Rohu, Scoliodon
(ii) Three-chambered heart: Frog, Salamander
(iii) Incomplete four-chambered heart: Flying lizard, Pigeon, Bat, Whale
(iv) Complete four-chambered heart: Crocodile, Ostrich, King cobra

Answer 1

The four-chambered heart is considered to be the most advanced type of heart and is also known as the complete form of a heart with the presence of auricles and ventricles and the septum separating them. This type of heart has no mixing of oxygenated and deoxygenated blood.

Complete answer:
- The two-chambered heart is the most primitive type of heart system present. It has only one auricle and one ventricle present. These types of hearts are usually present in the fishes. The auricle takes in the blood from the gills of the fish which is oxygen-rich in nature and then pumps to the ventricle which then pumps to the rest of the body parts so that they can receive oxygen-rich blood. The examples of this type of heart are rohu and scoliodon.
- The three-chambered heart is mostly present in the amphibians. This type of heart has two auricles and one ventricle. The oxygenated blood is pumped into the auricle and then is pumped into the ventricle. The ventricle then pumps the blood to the body. Then the auricle having deoxygenated blood transfers the blood into the ventricle so that it can get oxygenated. This type of system in the heart sometimes leads to the mixing of the both types of blood. The examples are frog and salamander.
- The complete four-chambered heart is the one that is present in humans. It has two auricles and two ventricles and the oxygenated and deoxygenated blood are sent to other parts of the body in their own path. No mixing of the blood takes place. An example is Crocodile, Ostrich, Pigeon, Bat, Whale.
So, the answer is ‘(i) Two-chambered heart: Rohu, Scoliodon
(ii) Three-chambered heart: Frog, Salamander
(iii) Incomplete four-chambered heart: Flying lizard, King cobra
(iv) Complete four-chambered heart: Crocodile, Ostrich, Pigeon, Bat, Whale’.

Note: The most primitive circulatory system has the absence of the heart and the most advanced system is of a four-chambered heart. The three-chambered heart is mostly present in the reptiles but the crocodile is the only reptile that has a four-chambered heart instead of three.