Question

Match the column.

Column 1	Column 2
SA node	Contraction
Water circulation	Right auricle
RBCs	Immunity
WBCs	Sponges
Systole	O2 transport

Answer 1

(A) SA node (II) Right auricle

1. SA node stands for the sinoatrial node.
2. It is present in the right upper chamber of the heart which is known as the right auricle or right atrium.
3. The SA node is the site for the beginning of the heartbeat.

(B) Water circulation (IV) Sponges

1. Sponges are organisms that are generally found in marine habitats.
2. Their body consists of multiple pores which allow the passage of water.
3. Water circulation in the sponge help in providing nutrients and bringing in oxygen.
4. It also plays an important role in the excretion of waste materials.

(C) RBCs (V) O₂ transport

1. RBCs stand for red blood corpuscles.
2. They are the biconcave-shaped blood cells that lack a nucleus.
3. They help in carrying oxygen molecules and transport them to the organs and tissue which require oxygen.

(D) WBCs (III) Immunity

1. WBCs stand for white blood corpuscles.
2. They are mainly known for fighting against germs and infections invading our bodies and providing immunity against these infections.

(E) Systole (I) Contraction

1. Systole is a condition during which the ventricles present on both sides contract and release the blood in the pulmonary artery and aorta respectively.
2. The pulmonary artery carries the deoxygenated blood to the lungs for the process of oxygenation.
3. The aorta is the largest artery that carries the oxygenated blood from the heart to all the organs of the body.

	Column I		Column II
(A)	SA node	(II)	Right auricle
(B)	Water circulation	(IV)	Sponge
(C)	RBCs	(V)	O2 transport
(D)	WBCs	(III)	Immunity
(E)	Systole	(I)	Contraction