(Class – XI)
Question 1:
Name the components of the formed elements in the blood and mention one major
function of each of them.
Answer 1:
The component elements in the blood are:
(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 millimetre 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.
Question 2:
What is the importance of plasma proteins?
Answer 2:
Plasma is the colourless fluid of blood which helps in the transport of food, CO2, waste
products, and salts. It constitutes about 55% of blood. About 6.8% 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.
1
, Question 3:
Match column I with column II:
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 3:
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
Question 4:
Why do we consider blood as a connective tissue?
Answer 4:
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.
Like the other connective tissues, blood is mesodermal in origin.
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.
2
Question 1:
Name the components of the formed elements in the blood and mention one major
function of each of them.
Answer 1:
The component elements in the blood are:
(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 millimetre 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.
Question 2:
What is the importance of plasma proteins?
Answer 2:
Plasma is the colourless fluid of blood which helps in the transport of food, CO2, waste
products, and salts. It constitutes about 55% of blood. About 6.8% 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.
1
, Question 3:
Match column I with column II:
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 3:
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
Question 4:
Why do we consider blood as a connective tissue?
Answer 4:
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.
Like the other connective tissues, blood is mesodermal in origin.
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.
2
