Function of WBCs is to
- Transport oxygen
- Help in clotting of blood
- Provide immunity
- Provide storage of food
Answer
Provide immunity
Reason — WBCs provide immunity by destroying the disease causing germs and producing antibodies.
RBCs transport oxygen. Platelets help in clotting of blood. Blood cells do not provide storage of food.
Blood Capillary is a
- Broad tube
- Artery with thick wall
- Vein with large lumen
- Narrow tube made up of endothelium only
Answer
Narrow tube made up of endothelium only
Reason — Blood capillary is narrow blood vessel whose walls have a single layer of cells called endothelium.
Blood capillaries are not broad. They are the smallest and narrowest blood vessels in the body, so narrow that blood cells pass through them one at a time. Arteries have thick, elastic, muscular walls and high-pressure blood flow. Capillaries are very thin and are not arteries. Veins have thinner walls than arteries and wide lumen. Capillaries do not have a large lumen; they are extremely narrow.
Nucleus is absent in
- RBCs
- WBCs
- All blood cells
- Liver cells
Answer
RBCs
Reason — RBCs have no nucleus because they need space for haemoglobin to carry more oxygen.
White blood cells do have a nucleus. Liver cells are ordinary body cells and also have a nucleus.
The only artery which carries deoxygenated blood is
- Hepatic artery
- Pulmonary artery
- Aorta
- Renal artery
Answer
Pulmonary artery
Reason — Pulmonary artery leaves the right ventricle of the heart carrying the deoxygenated blood to the lungs for oxygenation.
Hepatic artery carries oxygenated blood to the liver. Aorta carries oxygenated blood from the heart to the whole body. Renal artery carries oxygenated blood to the kidneys.
Sphygmomanometer measures
- Pulse rate
- Heart beat
- Blood pressure
- Brain activity
Answer
Blood pressure
Reason — Sphygmomanometer is an instrument which is used to find out blood pressure of the body.
Pulse rate is measured by feeling the pulse or using a pulse monitor. Heartbeat is the action of the heart; it is not directly measured by this instrument. Brain activity measured using an EEG (Electroencephalogram).
Pulmonary vein carries
- Oxygenated blood
- Deoxygenated blood
- Glucose-rich blood
- CO2 laden blood
Answer
Oxygenated blood
Reason — Oxygenated blood from the lungs returns to the left auricle via pulmonary veins.
Deoxygenated blood is carried by the pulmonary artery (not vein). Glucose-rich blood is not specifically related to this vessel. CO2 laden blood is carried to the lungs by the pulmonary artery.
The blood tastes saltish due to the presence of dissolved:
- Sodium chloride
- Potassium chloride
- Ammonium nitrate
- Sodium nitrate
Answer
Sodium chloride
Reason — The blood tastes saltish due to dissolved minerals like sodium chloride.
Potassium chloride is present in blood but not the main reason for saltish taste. Ammonium nitrate is not a natural component of blood. Sodium nitrate is not present in blood in significant amount.
Which of the following is an organ of the human cardiovascular system ?
- Liver
- Heart
- Kidney
- Lung
Answer
Heart
Reason — The heart is the main pumping organ of the human cardiovascular system. It pumps blood through the blood vessels to all parts of the body. Therefore, it is an organ of the cardiovascular system.
Liver is digestive organ involved in metabolism and detoxification. Kidney is part of the excretory system, filters waste from blood. Lung is part of the respiratory system, helps in gas exchange.
Haemoglobin consists of :
- Iodine + Proteins
- Iron + Amino acids
- Iron + Proteins
- Globin + Proteins
Answer
Iron + Proteins
Reason — Haemoglobin is an iron and protein compound found within RBCs. It acts as the "oxygen-carrier".
Iodine is related to thyroid hormones, not haemoglobin. Amino acids form proteins, but haemoglobin is specifically a protein with iron-containing haem groups. Globin itself is already a protein; haemoglobin is globin + haem (iron-containing part).
Which of the following blood vessels carries deoxygenated blood to the heart ?
- Pulmonary artery
- Aorta
- Pulmonary vein
- Vena cavae
Answer
Vena cavae
Reason — The Superior Vena Cava and the Inferior Vena Cava brings deoxygenated blood from the upper and lower parts of the body to the right auricle of the heart.
Pulmonary artery carries deoxygenated blood, but from the heart to the lungs (not to the heart). Aorta carries oxygenated blood from the heart to the body. Pulmonary vein carries oxygenated blood from the lungs to the heart.
Assertion: Blood is the main transporting medium in the human body which carries nutrients, respiratory gases and metabolic wastes. It flows unidirectionally, that is in one direction only.
Reason: The flow of blood is always unidirectional to ensure that oxygenated and deoxygenated blood reach the correct organs without mixing.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Answer
Both A and R are true and R is the correct explanation of A.
Reason — A is true as blood transports nutrients, oxygen, carbon dioxide, hormones, and waste materials throughout the body. Blood circulation is generally unidirectional because of the pumping action of the heart and the presence of valves.
R is true as unidirectional flow ensures that oxygenated blood and deoxygenated blood are delivered to the correct organs efficiently without mixing.
Therefore, Both A and R are true and R is the correct explanation of A is the correct option.
Assertion: Arteries have thin muscular walls with wider lumen which carry the blood away from the heart to other parts of the body.
Reason: Arteries usually carry oxygenated blood from the heart to different parts of the body so that tissues receive a continuous supply of oxygen.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Answer
A is false but R is true.
Reason — A is false as arteries do carry blood away from the heart, but they have thick, elastic, muscular walls and narrow lumen.
R is true as arteries usually carry oxygenated blood from the heart to body tissues to provide oxygen.
Therefore, A is false but R is true is the correct option.
Assertion: The left side of the heart receives deoxygenated blood whereas the right side distributes oxygenated blood.
Reason: The oxygenated and deoxygenated blood do not intermix at any point of time.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Answer
A is false but R is true.
Reason — A is false as the right side of the heart receives deoxygenated blood from the body and sends it to the lungs. The left side of the heart receives oxygenated blood from the lungs and pumps it to the whole body.
R is true as oxygenated and deoxygenated blood do not mix in the human heart because the heart has separate chambers for each type of blood.
Therefore, A is false but R is true is the correct option.
Assertion: The pulmonary circulation transports blood only between the heart and the lungs.
Reason: During pulmonary circulation, deoxygenated blood is received from the heart to the lungs where it is oxygenated and then carried back to the heart.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Answer
Both A and R are true and R is the correct explanation of A.
Reason — A is true as pulmonary circulation involves the movement of blood only between the heart and the lungs.
R is true as in pulmonary circulation, deoxygenated blood goes from the heart to the lungs through the pulmonary artery. In the lungs, the blood receives oxygen. Oxygenated blood then returns to the heart through the pulmonary veins.
Therefore, Both A and R are true and R is the correct explanation of A is the correct option.
Fill in the blanks with suitable words :
(a) The colour of a red blood cell is due to ...............
(b) The two lower chambers of the heart are called ...............
(c) The blood plasma contains dissolved substances such as ............... and ...............
(d) The ............... artery takes the blood from the ventricles to the lungs.
(e) The instrument used to find out the blood pressure is known as ...............
(f) The blood loaded with carbon dioxide from the body comes into the ............... of the heart.
(g) The oxygen-rich blood from the lungs comes into the ............... of the heart.
(h) The oxygen-rich blood is pumped into different parts of the body through ...............
(i) The carbon dioxide loaded blood from the right ventricle is pumped into the lungs through ............... artery.
Answer
(a) Haemoglobin
(b) Ventricles
(c) Nutrients, Proteins, waste products and Hormones
(d) Pulmonary
(e) Sphygmomanometer
(f) Right Auricle
(g) Left Auricle
(h) Aorta
(i) Pulmonary
Match the terms given in column A with those of column B:
| Column A | Column B |
|---|---|
| (i) Haemoglobin | (a) Antibodies |
| (ii) Heart | (b) Distributing chambers |
| (iii) Leukocytes | (c) Oxygen carrier |
| (iv) Atria | (d) Pumping organ |
| (v) Ventricles | (e) Receiving chambers |
Answer
| Column A | Column B |
|---|---|
| (i) Haemoglobin | (c) Oxygen carrier |
| (ii) Heart | (d) Pumping organ |
| (iii) Leukocytes | (a) Antibodies |
| (iv) Atria | (e) Receiving chambers |
| (v) Ventricles | (b) Distributing chambers |
Given below are sets of four terms. Choose the odd one and write the category of the remaining terms :
(i) Erythrocytes, Leukoplasts, Leukocytes, Thrombocytes
(ii) Arteries, Atria, Capillaries, Veins
(iii) Heart, Kidney, Blood vessels, Blood
(iv) RBCs, WBCs, Haemoglobin, Platelets
(v) Diaphragm, Left atrium, Right ventricle, Pulmonary artery
Answer
(i) Odd one — Leukoplasts
Category of the remaining terms — Corpuscles (Blood cells)
(ii) Odd one — Atria
Category of the remaining terms — Blood vessels
(iii) Odd one — Kidney
Category of the remaining terms — Parts of Circulatory System
(iv) Odd one — Haemoglobin
Category of the remaining terms — Corpuscles (Blood cells)
(v) Odd one — Diaphragm
Category of the remaining terms — Parts of the heart
Differentiate between Platelets and WBC.
Answer
Difference between Platelets and WBCs:
| Platelets | WBCs |
|---|---|
| Platelets help in clotting of blood. | WBCs provide immunity by destroying the disease causing germs and producing antibodies. |
| Platelets are the smallest of the blood cells. | WBCs are larger than RBCs and Platelets. |
| Platelets does not have a nucleus. | WBCs have a distinct oval or lobed nucleus. |
Differentiate between Pulmonary artery and Pulmonary vein
Answer
Difference between Pulmonary artery and Pulmonary vein:
| Pulmonary artery | Pulmonary vein |
|---|---|
| The Pulmonary artery arises from the right ventricle of the heart. | The Pulmonary vein drains blood into the left atrium of the heart. |
| It carries deoxygenated blood from the right ventricle of the heart to each lung. | It carries oxygenated blood from each lung to the left atrium of the heart. |
Differentiate between Vena cava and Aorta
Answer
Difference between Vena cava and Aorta:
| Vena cava | Aorta |
|---|---|
| Vena 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 ventricle of the heart carrying oxygenated blood to all parts of the body through its branches. |
Differentiate between RBC and WBC
Answer
Difference between RBC and WBC:
| RBC | WBC |
|---|---|
| RBC do not have nucleus at maturity. | WBC have a large distinct oval or lobed nucleus . |
| RBC are small in size. | WBC are larger than RBC. |
| 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. |
Give any three differences between an Artery and a Vein.
Answer
Three differences between an Artery and a Vein are:
| Artery | Vein |
|---|---|
| Arteries carry blood away from the heart to various body parts. | Veins carry blood from different body parts to the heart. |
| Arteries have thick elastic and more muscular walls. | Veins have thin and less muscular walls. |
| Arteries carry oxygenated blood (except the pulmonary artery). | Veins carry deoxygenated blood (except the pulmonary vein). |
Blood consists of two parts - a liquid part and a cellular part. Name these parts and briefly describe them.
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 antibodies
- Platelets — The platelets are also called Thrombocytes. They are round in shape 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.
What is the role of haemoglobin in the blood?
Answer
Haemoglobin is an iron and protein compound present in the Red Blood Cells (RBCs). It acts as the Oxygen carrier as it binds with Oxygen transporting it to all the body tissues and cells. It also helps to remove carbon dioxide produced in the cells and carry it back to the lungs.
In which organ of our body does blood become oxygenated?
Answer
Blood becomes oxygenated in the lungs.
Which side of the heart (left or right) contains oxygenated blood?
Answer
The left side of the heart contains oxygenated blood.
Name the disease in which the number of platelets reduces to 25,000 - 30,000 per cu mm of blood. State its major symptoms.
Answer
Dengue fever is one such disease in which the number of platelets reduces to 25,000 - 30,000 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.
Name the following :
(i) Three components of circulatory system
(ii) Three kinds of blood vessels
(iii) Three kinds of corpuscles
(iv) Two types of blood circulation in human body
(v) Four categories of blood groups on the basis of the proteins found on the surface of RBCs.
Answer
(i) Blood, Blood vessels and Heart
(ii) Arteries, Veins and Capillaries
(iii) Erythrocytes (RBCs), Leukocytes (WBCs), Thrombocytes (Platelets)
(iv) Pulmonary Circulation and Systemic Circulation
(v) A, B, AB, and O
Define the terms given below :
(i) Haemoglobin
(ii) Capillaries
(iii) Aorta
(iv) Universal donor
(v) Blood pressure
Answer
(i) Haemoglobin — Haemoglobin is an iron and protein compound that is found within the Red Blood cells. It acts as the "oxygen-carrier".
(ii) Capillaries — Capillaries are the terminal branches of an artery, which rejoin to form a vein.
(iii) 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.
(iv) 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.
(v) Blood pressure — The pressure exerted by the blood on the walls of the arteries while flowing through them is called blood pressure.
Correct the following statements by changing the first/ last word only :
(i) Robert Hooke identified the different types of blood groups.
(ii) A faster heart beat is usually an indication of hypotension.
(iii) WBCs produce special substances called antigens.
(iv) Thrombocytes contain haemoglobin.
(v) Arteries possess valves.
Answer
(i) Karl Landsteiner identified the different types of blood groups.
(ii) A faster heart beat is usually an indication of hypertension.
(iii) WBCs produce special substances called antibodies.
(iv) Erythrocytes contain haemoglobin.
(v) Veins possess valves.
Write one important role of each of the following:
(i) Erythrocytes
(ii) Thrombocytes
(iii) Arteries
(iv) Vena cavae
(v) Heart
Answer
(i) Erythrocytes contain an iron and protein compound called Haemoglobin that acts as the "oxygen-carrier".
(ii) 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.
(iii) Arteries are crucial blood vessels that carry the blood away from the heart (oxygenated blood) to different parts of the body.
(iv) The vena cava's primary role is to return deoxygenated blood from the body back to the heart.
(v) The heart, acting as a pump, pushes and receives the blood to and from the whole body through the blood vessels.
What are the two diseases in which the number of platelets in the human body are lowered to a great extent ?
Answer
The two diseases in which the number of platelets in the human body are lowered to a great extent are:
- Purpura
- Dengue.
Name the three kinds of blood vessels found in human beings. With the help of suitable diagrams, differentiate between them.
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:
| Arteries | Veins | Capillaries |
|---|---|---|
| An 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. |
State briefly, the difference between white blood cells and the red blood cells.
Answer
Difference between White blood cells and Red blood cells:
| White Blood Cells | Red Blood Cells |
|---|---|
| WBCs 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. |
| WBCs are colourless and they lack haemoglobin. | RBCs have red colour due to the presence of haemoglobin protein. |
| WBCs provide immunity by destroying the disease causing germs and producing antibodies. | 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. |
You can see some blood vessels on the outside of the hands specially in older people. Are those veins or arteries? How can you confirm your answer?
Answer
These blood vessels seen on the outside of the hands are Veins. Usually, arteries are deeply placed in the body whereas Veins are placed more superficially.
Given alongside is a diagram of human heart showing its internal structure. Label the parts marked 1 to 5, and answer the following questions.
(a) Which type of blood is carried by the blood vessel marked 2?
(b) Name the main artery which takes the blood from heart to different parts of the body?
(c) Which chamber of the heart receives oxygenated blood from the lungs?
Answer
The marked parts are:
- Left pulmonary artery
- Superior vena cava
- Left pulmonary vein
- Right auricle
- Left ventricle
a) Deoxygenated blood is carried by the blood vessel marked 2 (Superior vena cava).
b) Aorta
c) Left auricle
Distinguish between arteries and veins on the basis of their structure.
Answer
Differences between arteries and veins on the basis of their structure:
| Arteries | Veins |
|---|---|
| Arteries 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. |
Distinguish between atria and ventricles on the basis of their location in the heart.
Answer
Differences between atria and ventricles on the basis of their location in the heart:
| Atria | Ventricles |
|---|---|
| The atria are the two upper chambers of the heart. | The ventricles are the two lower chambers of the heart. |
Distinguish between Blood groups 'AB' and 'O' on the basis of antigens.
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. |
Distinguish between pulmonary and systemic circulation on the basis of direction of blood flow.
Answer
Differences between pulmonary and systemic circulation on the basis of direction of blood flow:
| Pulmonary Circulation | Systemic Circulation |
|---|---|
| In 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. |
Distinguish between pulmonary artery and pulmonary vein on the basis of the kind of blood they carry.
Answer
Differences between pulmonary artery and pulmonary vein on the basis of the kind of blood they carry:
| Pulmonary Artery | Pulmonary Vein |
|---|---|
| The pulmonary artery carries deoxygenated blood from the heart to the lungs. | The pulmonary vein carries oxygenated blood from the lungs back to the heart. |
Kritika is a 12-year-old girl who recently began feeling unusually tired and short of breath. She loves sports and normally plays and runs with ease. But these days, even simple activities like climbing stairs or walking to school leave her out of breath. One evening, she feels her heart racing and beating fast. She can even feel the thumping in her chest. Answer the following questions:
(i) What is the normal heart rate of an adult at an average?
(ii) What will be the effect of a thumping heart on the pulse?
(iii) Which blood vessel (artery/vein/capillary) can be pressed gently with fingers to measure pulse rate?
(iv) Mention one suitable piece of advice for Kritika before she goes to a doctor.
Answer
(i) The normal heart rate of an adult at average is about 72 beats per minute.
(ii) A thumping or fast-beating heart will make the pulse rate increase. The pulse will feel faster and stronger than normal.
(iii) The pulse rate is measured by gently pressing the finger over an artery on the wrist along the side of the thumb.
(iv) One suitable advice for Kritika before going to a doctor is that she should take proper rest and avoid heavy physical activities or excessive running until she is examined by a doctor.