Leucocytes - class-XI

Basophils: 0.5–1.0 percent. Eosinophils: 1–4 percent. Lymphocytes: 20–40 percent. Monocytes: 2–8 percent, Neutrophils: 40% to 60% Lymphocytes: 20% to 40%.

The relative proportions of the different types of white blood cells are: Neutrophils (roughly 60 – 70%), Lymphocytes (roughly 20 – 30%), Monocytes (approximately 1 – 6%), Eosinophils (approximately 1 – 3%), Basophils (less than 1%).

Thus, the correct answer is 'Neutrophils --> Lymphocytes Monocytes --> Acidophils -->Basophils.'

Immunocomplexes also called antigen-antibody complexes are harmful and long deposition of then inside the cell can lead to various autoimmune disorders and primarily removed from the cell by phagocytosis in which eosinophils and monocytes (destruction of antibody)  have an important role to play.

Neutrophils are sexually dimorphic. Neutrophils from females exhibit a small additional X chromosome structure, known as a "neutrophil drumstick".

White blood cells (WBCs) or leucocytes are the primary cells responsible for the immune system's defense against pathogens.

Phagocytotic activity is the process of engulfing or ingestion of food or bacteria.

Granulocytes are a category of white blood cells characterized by the presence of granules in their cytoplasm. They are also called polymorphonuclear leukocytes or polymorphonuclear neutrophils because of the varying shapes of the nucleus, which is usually lobed into three segments. These are granulocytes involved in fighting off pathogens, such as bacteria and fungi.

Leukopenia, or a decrease in white blood cells, is often associated with deficiencies in folate or vitamin B12. While the question lists Cyanacobalamine (B12) as correct, it is a common medical fact that both B12 and Folic acid deficiencies cause this condition, making the question slightly ambiguous.

A  mast cell  is derived from the myeloid stem cell and contains many granules rich in histamine and heparin. Mast cells play an important role in allergy and anaphylaxis and are involved in wound healing and defence against pathogens. So, the correct answer is option B.

Leucocytes do not disintegrate in spleen and liver, in fact they are produced in bone marrow.
Neutrophils are mainly responsible for protection against infection. When they come across the bacteria or any other foreign bodies, they engulf them through phagocytosis, thus playing a important role in cell defense. 

WBC's are amoeboid in shape due to which they can easily squeeze through the walls of the capillaries at the site of injury by the process known as diapedesis and engulf the damaged cells by phagocytosis. They are nucleated cells and excess of WBCs causes cancer known as leukaemia. 

White blood cells(WBCs) are the body's defense systems. They attack foreign bodies that invaded the blood or any part of the body. Foreign bodies like the bacteria, viruses and the fungi rendering them less invasive and even destroys them. They are cells involved in the “inflammatory” response. This response develops when tissue is damaged or invaded by microbes. Neutrophils specialize is killing bacteria. Eosinophils kill parasites. Monocytes control inflammation by releasing cytokines. Lymphocytes recognize and destroy cells infected by viruses or transplanted foreign cells. 

Percentage distribution of leukocyte are as follows:

Leucocytes or the white blood cells are concerned with immunity. They perform phagocytosis, antigen-presenting, the release of antibodies, release of cytokines, opsonization etc. to keep the immunity of the body against the pathogens. Erythrocytes or the red blood cells are responsible for the transportation of oxygen. Thrombocytes or the platelets are responsible for blood clotting.

The components of blood consists of red blood cells, white blood cells and platelets. Of these, only white blood cells are true cells or complete cells as they have a nucleus, organelles and other cell structures and processes such as expressing proteins.
Thus, the correct answer is option (A).

Diapedesis is the specific physiological process where white blood cells, particularly neutrophils, migrate through the endothelial walls of capillaries to reach sites of infection or tissue damage.

A high white blood cell(leukocyte) count isn't a specific disease, but it can indicate another problem, such as infection, stress, inflammation, trauma, allergy, or certain diseases. That's why a high white blood cell count usually requires further investigation.

Plasma cells are differentiated B-lymphocytes that are specialized for the mass production and secretion of antibodies into the bloodstream.

• Eosinophils: These cells play important role in immunity and allergic reactions. These make about 1 - 5% of total leucocytes.
• Basophils: These cells contain heparin, serotonin and histamine. These make about 0.5 - 2.7% of total leucocytes.
• Neutrophils: These cells perform phagocytosis and also destroy bacteria. These make about 60 - 70% of total leucocytes.

• Lymphocytes: These cells are of two types, B lymphocytes that maintain humoral immunity and T lymphocytes which maintain cell mediated immunity. These make about 20 - 40% of total leucocytes.
• Monocytes: These cells are actively motile and phagocytic cells. These make about 2 - 7% of total leucocytes.

Thrombocytes, also known as platelets, are cell fragments involved in blood clotting rather than being true white blood cells (leukocytes).

The standard mnemonic for leukocyte abundance is Never Let Monkeys Eat Bananas: Neutrophils (60-70%), Lymphocytes (20-25%), Monocytes (3-8%), Eosinophils/Acidophils (2-4%), and Basophils (0.5-1%).

• Eosinophils- These cells play important role in immunity and allergic reactions.
• Basophils- These cells secrete histamine, serotonin and heparin.
• Neutrophils- These cells perform phagocytosis.

• Lymphocytes- These cells produce antibodies.
• Monocytes- These cells are phagocytic.

Thus, the correct answer is (A).

I.Barr body is an another name of neutrophilis is false – because Barr body is a inactive X chromosome.

II.Agranulocytes are formed in the red bone marrow – False, because, they are  formed from the bone marrow of the human being

III.Granulocytes are formed in the spleen and lymph node – False, because granulocytes are formed from myeloid stem cells

IV.Lymphocytes exists as two major types, B and T lymphocytes – True.

So, the correct option is ‘I,
II and III’.

The white blood cells or leukocytes are the blood components primarily involved in fighting the infection.

Lymphocytes are the smallest leukocytes with a rounded nucleus. They flow through the lymphatic system or fluid and consist of Natural killer cells, B-Lymphocytes and T-lymphocytes and defend the body against pathogens and infections.

Lymphocytes a type of WBC or Leukocyte can squeeze through the walls of the capillaries into the interstitial fluid to the site of infection,  or in response to inflamation by a process called as diapedesis.

Erythrocytes or red blood cells (RBC) are the most abundant of all the cells in blood. A healthy adult man has, on an average, 5 millions to 5.5 millions of RBCs per cubic mm of blood. RBCs are formed in the red bone marrow in the adults. RBCs are devoid of nucleus in most of the mammals and are biconcave in shape. They have a red coloured, iron containing complex protein called haemoglobin, hence the colour and name of these cells. These molecules play a significant role in transport of respiratory gases like oxygen and carbon dioxide.

A.Eoisinophil - These cells are 10 - 15 µm in diameter

B.Basophils - They are 14-16 µm in diameter, 

C.Neutrophil – The cells are 12 to 17 µm in diameter

D.Monocyte – The cells are 15 to 30 µm in diameter.

So,
the correct option is ‘Eosinophils’.

The bone marrow produces white blood cells which function in housekeeping and defense by fighting against the invading pathogens.

Macrophages are scavenging cells derived from monocytes and are found all over the body. These infiltrate the tissue during an inflammatory response.