Biology Class 11 NCERT Solutions: Chapter 18 Body Fluids and Circulation Part 1

Download PDF of This Page (Size: 929K)

Q: 1. Name the components of the formed elements in the blood and mention one major function of each of them.

Answer:

The component elements in the blood are:

The component formed elements in the blood

The Component Formed Elements in the Blood

The component formed elements in the blood

(1) Erythrocytes:

They are the most abundant cells and contain the red pigment called haemoglobin. They carry oxygen to all parts of the body. Red blood cells are produced continuously in some parts of the body such as the marrow of long bones, ribs, etc. There are about 4 - 6 million RBCs per cubic millimeter of blood.

(2) Leukocytes

Leucocytes are colourless cells. These cells do not contain haemoglobin. They are the largest cells of the body and are divided into two main categories.

(A) Granulocytes

These leucocytes have granules in their cytoplasm and include neutrophils, eosinophils, and basophiles. Neutrophils are phagocytic cells that protect the body against various infecting agents. Eosinophils are associated with allergic reactions, while basophiles are involved in inflammatory responses.

(B) Agranulocytes

Lymphocytes and monocytes are agranulocytes. Lymphocytes generate immune responses against infecting agents, while monocytes are phagocytic in nature.

(3) Platelets

Platelets are small irregular bodies present in blood. They contain essential chemicals that help in clotting. The main function of platelets is to promote clotting.

Image of the formed elements of blood

Image of the Formed Elements of Blood

Image of the formed elements of blood

Q: 2. What is the importance of plasma proteins?

Answer:

Plasma is the colourless fluid of blood, which helps in the transport of food, , waste products, and salts. It constitutes about of blood. About of the plasma is constituted by proteins such as fibrinogens, globulins, and albumins. Fibrinogen is a plasma glycoprotein synthesised by the liver. It plays a role in the clotting of blood. Globulin is a major protein of the plasma. It protects the body against infecting agents.

Albumin is a major protein of the plasma. It helps in maintaining the fluid volume within the vascular space.

Image shows the plasma proteins

Image Shows the Plasma Proteins

Image shows the plasma proteins

Q: 3. Match column I with column II:

Match Col 1 With 2 Question
Match col 1 with 2 question

Column I

Column II

(A)

Eosinophils

(i)

Coagulation

(B)

RBC

(ii)

Universal Recipient

(C)

AB Group

(iii)

Resist Infections

(D)

Platelets

(iv)

Contraction of Heart

(E)

Systole

(v)

Gas Transport

Answer:

Match Col 1 With 2
Match col 1 with 2

Column I

Column II

(A)

Eosinophils

(iii)

Resist Infections

(B)

RBC

(v)

Gas Transport

(C)

AB Group

(ii)

Universal Recipient

(D)

Platelets

(i)

Coagulation

(E)

Systole

(iv)

Contraction of Heart

Q: 4. Why do we consider blood as a connective tissue?

Answer:

Connective tissues have cells scattered throughout an extra-cellular matrix. They connect different body systems. Blood is considered as a type of connective tissue because of two reasons.

(i) Like the other connective tissues, blood is mesodermal in origin.

(ii) It connects the body systems, transports oxygen and nutrients to all the parts of the body, and removes the waste products. Blood has an extra-cellular matrix called plasma, with red blood cells, white blood cells, and platelets floating in it.

Image of the blood as connective tissue

Image of the Blood as Connective Tissue

Image of the blood as connective tissue

Q: 5. What is the difference between lymph and blood?

Answer:

Lymph vs Blood
Lymph vs Blood

Lymph

Blood

1.

It is a colourless fluid that does not contain RBCs.

1.

It is a red-coloured fluid that contains RBCs.

2.

It contains plasma and lesser number of WBCs and platelets.

2.

It contains plasma, RBCs, WBCs, and platelets.

3.

It helps in body defence and is a part of

the immune system.

3.

It is associated with the circulation of oxygen and carbon dioxide.

4.

Its plasma lacks proteins.

4.

Its plasma has proteins, calcium, and phosphorus.

5.

It transports nutrients from the tissue cells to the blood, through lymphatic vessels.

5.

It transports nutrients and oxygen from one organ to another.

6.

The flow of lymph is slow.

6.

The flow of blood in the blood vessels is fast.

The difference between lymph and blood

The Difference Between Lymph and Blood

The difference between lymph and blood

Q: 6. What is meant by double circulation? What is its significance?

Answer:

Double circulation is a process during which blood passes twice through the heart during one complete cycle. This type of circulation is found in amphibians, reptiles, birds, and mammals. However, it is more prominent in birds and mammals as in them the heart is completely divided into four chambers - the right atrium, the right ventricle, the left atrium, and the left ventricle.

The movement of blood in an organism is divided into two parts:

Image shows the double circulation

Image Shows the Double Circulation

Image shows the double circulation

(i) Systemic circulation

(ii) Pulmonary circulation

Systemic circulation involves the movement of oxygenated blood from the left ventricle of the heart to the aorta. It is then carried by blood through a network of arteries, arterioles, and capillaries to the tissues. From the tissues, the deoxygenated blood is collected by the venules, veins, and vena cava, and is emptied into the left auricle.

Pulmonary circulation involves the movement of deoxygenated blood from the right ventricle to the pulmonary artery, which then carries blood to the lungs for oxygenation. From the lungs, the oxygenated blood is carried by the pulmonary veins into the left atrium. Hence, in double circulation, blood has to pass alternately through the lungs and the tissues.

Significance of double circulation:

The separation of oxygenated and deoxygenated blood allows a more efficient supply of oxygen to the body cells. Blood is circulated to the body tissues through systemic circulation and to the lungs through pulmonary circulation.

Image of the advantages of double circulation

Image of the Advantages of Double Circulation

Image of the advantages of double circulation