Question

Match the following pairs correctly .

Fish	Three Chambered heart
Lizard	Incomplete four chambered heart
Man	Two chambered heart
Frog	Complete four chambered heart

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

Answer 1

Answer: (B)

(i)- c , (ii)- b , (iii)- d , (iv)- a

Fishes have a two chambered heart with one auricle and one ventricle with two accessory chambers, sinus venosus and conus arteriosus. They handle only deoxygenated blood and thus it is called venous heart.

Amphibian heart receives both oxygenated and deoxygenated blood and is often called arteriovenous heart. It is 3-chambered as in frog with two auricles and one ventricle. The heart supplies mixed blood to the body parts.

In reptiles as in lizard, the heart also receives both oxygenated and deoxygenated blood . It is incompletely four chambered having two auricles and partly divided ventricle. Only one accessory chamber sinus venosus is present.

Avian and mammalian heart is complete four chambered having two auricles and two ventricles. The right auricle receives the deoxygenated blood from the body and sends it to the right ventricle that pumps it to the lungs via a pulmonary arch for oxygenation. The left auricle receives oxygenated blood from lungs and sends it to the left ventricle which pumps it to the body through a single aortic arch. Thus the oxygenated and deoxygenated blood remain fully separate.

Thus, the correct answer is option B.