Question

Read the following and answer any four questions from 7(i) to 7(v). 4 x ½ = 2

The tubes – blood vessels - Arteries are the vessels which carry blood away from the

heart to various organs of the body. Since the blood emerges from the heart under high

pressure, the arteries have thick, elastic walls. Veins collect the blood from different

organs and bring it back to the heart. They do not need thick walls because the blood is

no longer under pressure, instead they have valves that ensure that the blood flows

only in one direction. On reaching an organ or tissue, the artery divides into smaller

and smaller vessels to bring the blood in contact with all the individual cells. The

smallest vessels have walls which are one-cell thick and are called capillaries.

Exchange of material between the blood and surrounding cells takes place across this

thin wall. The capillaries then join together to form veins that convey the blood away

from the organ or tissue.



(i) A blood vessel which carries blood back to the heart is :

(a) artery (b) vein (c) capillary (d) platelet

(ii) The blood vessel which carries oxygenated blood from the lungs to the heart is :

(a) main artery (b) pulmonary artery (c) main vein (d) pulmonary vein

(iii) The smaller vessels in which arteries are divided after entering the body organs

are called

(a) cytokinesis (b) granum (c) centrioles (d) arterioles

(iv) After entering into the tissues, the arteries are divided into

(a) aorta (b) atrium (c) capillaries (d) veins(v) The blood vessels in which there are no valves includes

(a) veins and capillaries (b) capillaries and arteries

(c) arteries and nerves (d) veins and arteries​

Answer 1

Answer:

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