Question 1

Question 1Name the three kinds of blood vessels found in human beings. With the help of suitable diagrams, differentiate between them.

Accepted Answer

The three kinds of blood vessels found in human beings are Arteries, Veins and Capillaries.Below diagram shows the differences between Artery, Vein and Capillaries:ArteriesVeinsCapillariesAn artery is a vessel which carries the blood away from the heart to other parts of the body.A vein is a vessel which carries the blood from an organ towards the heart.Capillaries are the terminal branches of an artery, which rejoin to form a vein.An artery has thick, elastic and more muscular walls.A vein has thin and less muscular walls with valves.Walls of the capillary are made up of single layer of cells (endothelium) with no muscles.The blood in it flows with jerk and under great force.The valves prevent the back flow of the blood flowing towards the heart.The wall of capillary is very thin, to enable an exchange of nutrients waste products and gases between the blood and the body fluids.

Question 2

Question 2State briefly, the difference between white blood cells and the red blood cells.

Accepted Answer

Difference between White blood cells and Red blood cells:White Blood CellsRed Blood CellsWBCs are amoeboid having irregular shape.RBCs are circular or biconcave disc shaped.WBCs have distinct oval or lobed nucleus.RBCs do not have nucleus at maturity.WBCs are larger than RBCs.RBCs are small in size.RBCs have red colour due to the presence of haemoglobin protein.WBCs are colourless and they lack haemoglobin.RBCs carry oxygen from lungs to all the body tissues and cells and remove carbon dioxide produced in the cells and carry it back to the lungs.WBCs provide immunity by destroying the disease causing germs and producing antibodies.

Question 3

Question 5(i)Distinguish between arteries and veins on the basis of their structure.

Accepted Answer

Differences between arteries and veins on the basis of their structure:ArteriesVeinsArteries have thick, elastic and muscular walls to withstand high pressure.Veins have thin and less muscular walls as the blood pressure is lower.They lack valves (except the pulmonary trunk and the aorta).Valves are usually present to prevent the backflow of blood.Arteries are usually, deeply placed in the body.Veins are usually placed more superficially.

Question 4

Question 5(iii)Distinguish between Blood groups 'AB' and 'O' on the basis of antigens.

Accepted Answer

Differences between Blood groups 'AB' and 'O' on the basis of antigens:Blood group 'AB'Blood group 'O'The persons whose RBCs have both types of antigens, i.e. both A and B, belong to the 'AB' blood group.The persons whose RBCs have no antigens, i.e., neither A nor B have the 'O' blood group.

Question 5

Question 5(iv)Distinguish between pulmonary and systemic circulation on the basis of direction of blood flow.

Accepted Answer

Differences between pulmonary and systemic circulation on the basis of direction of blood flow:Pulmonary CirculationSystemic CirculationIn pulmonary circulation, the blood flows from the heart to the lungs and back to the heart.In systemic circulation, the blood flows from the heart to the entire body (except lungs) and back to the heart.

Question 6

Question 5(v)Distinguish between pulmonary artery and pulmonary vein on the basis of the kind of blood they carry.

Accepted Answer

Differences between pulmonary artery and pulmonary vein on the basis of the kind of blood they carry:Pulmonary ArteryPulmonary VeinThe pulmonary artery carries deoxygenated blood from the heart to the lungs.The pulmonary vein carries oxygenated blood from the lungs back to the heart.

Question 7

Question 1(c)Differentiate between Vena cava and Aorta

Accepted Answer

Difference between Vena cava and Aorta:Vena cavaAortaVena cava is a large vein.Aorta is the largest artery.It carries deoxygenated blood from the upper and lower parts of the body to the right auricle of the heart.It leaves the left auricle of the heart carrying oxygenated blood to all parts of the body through its branches.

Question 8

Question 1(d)Differentiate between RBC and WBC

Accepted Answer

Difference between RBC and WBC:RBCWBCRBC do not have nucleus at maturity.WBC have a large distinct oval or lobed nucleus .WBC are larger than RBC.RBC are small in size.RBC have red colour due to the presence of haemoglobin protein.WBC are colourless and they lack haemoglobin.RBC carry oxygen from lungs to all the body tissues and cells and remove carbon dioxide produced in the cells and carry it back to the lungs.WBC provide immunity by destroying the disease causing germs and producing antibodies.

Question 9

Question 3Blood consists of two parts - a liquid part and a cellular part. Name these parts and briefly describe them.

Accepted Answer

Blood is a red coloured fluid which consists of two parts:Liquid part — The liquid part of the blood is called Plasma. Plasma is yellow in colour. 90% of Plasma is water and the remaining 10% consists of dissolved proteins, nutrients, waste product and hormones.Cellular part — The cellular part of the blood is called Corpuscles. The corpuscles are of three types:Red Blood Cells (RBCs) — RBCs are also called as Erythrocytes. They carry oxygen from lungs to all the body tissues and cells and remove carbon dioxide produced in the cells and carry it back to the lungs. RBCs are circular or biconcave disc shaped. A mature RBC does not contain nucleus. Haemoglobin present in RBCs helps in transport of oxygen and gives them the red colour.White Blood Cells (WBCs) — WBCs are also called Leukocytes. They are colourless and lack haemoglobin. They are larger than RBCs and have a distinct oval or lobed nucleus. WBCs provide immunity by destroying the disease causing germs and producing antibodiesPlatelets — The platelets are also called Thrombocytes. They are round in shaped and the smallest in size. They help in the clotting of blood which prevents excessive blood loss and direct entry of disease causing germs into the blood through cuts and wounds.

Question 10

Question 7Name the disease in which the number of platelets reduces to 25,000 - 30,000 per cu mm of blood. State its major symptoms.

Accepted Answer

Dengue fever is one such disease in which the number of platelets reduces to 25,000 - 30,0000 per cu mm of blood. The major symptoms of dengue are high fever, rashes or red spots on body, vomiting, pain in abdomen or back of the eyes and muscles.

Question 11

Question 8Name the following :Three components of circulatory systemThree kinds of blood vesselsThree kinds of corpusclesTwo types of blood circulation in human bodyFour categories of blood groups on the basis of the proteins found on the surface of RBCs.

Accepted Answer

Blood, Blood vessels and HeartArteries, Veins and CapillariesErythrocytes (RBCs), Leukocytes (WBCs), Thrombocytes (Platelets)Pulmonary Circulation and Systemic CirculationA, B, AB, and O

Question 12

Question 9Define the terms given below :HaemoglobinCapillariesAortaUniversal donorBlood pressure

Accepted Answer

Haemoglobin — Haemoglobin is an iron and protein compound that is found within the Red Blood cells. It acts as the "oxygen-carrier".Capillaries — Capillaries are the terminal branches of an artery, which rejoin to form a vein.Aorta — The aorta is the largest artery in the body and carries oxygenated blood from the left ventricle to all parts of the body through its branches.Universal donor — A person with O blood group can give blood to a person of any blood type and is therefore called a universal donor.Blood pressure — The pressure exerted by the blood on the walls of the arteries while flowing through them is called blood pressure.

Question 13

Question 10Correct the following statements by changing the first/ last word only :Robert Hooke identified the different types of blood groups.A faster heart beat is usually an indication of hypotension.WBCs produce special substances called antigens.Thrombocytes contain haemoglobin.Arteries possess valves.

Accepted Answer

Karl Landsteiner identified the different types of blood groups.A faster heart beat is usually an indication of hypertension.WBCs produce special substances called antibodies.Erythrocytes contain haemoglobin.Veins possess valves.

Question 14

Question 11Write one important role of each of the following:ErythrocytesThrombocytesArteriesVena cavaeHeart

Accepted Answer

Erythrocytes contain an iron and protein compound called Haemoglobin that acts as the "oxygen-carrier".The Thrombocytes help in the clotting of blood which prevents excessive blood loss and direct entry of disease causing germs into the blood through cuts and open wounds.Arteries are crucial blood vessels that carry the blood away from the heart (oxygenated blood) to different parts of the body.The vena cava's primary role is to return deoxygenated blood from the body back to the heart.The heart, acting as a pump, pushes and receives the blood to and from the whole body through the blood vessels.

Question 15

Question 12What are the two diseases in which the number of platelets in the human body are lowered to a great extent ?

Accepted Answer

The two diseases in which the number of platelets in the human body are lowered to a great extent are:PurpuraDengue.

The Circulatory System

Long Answer Questions

Short Answer Questions