Biology

Human Immunity and Blood

2,096 Questions

Human immunity and blood questions cover the physiological mechanisms protecting the body against diseases and the components of blood. Topics include blood groups, cell mediated immunity, monoclonal antibodies, and blood coagulation. These biology topics frequently appear in general science sections of competitive exams.

Blood groupsCell mediated immunityMonoclonal antibodiesBlood coagulationCancer immunology

Human Immunity and Blood Questions

Multiple choice

________ helps to assist clotting of blood.

  1. RBC

  2. WBC

  3. Platelet

  4. Plasma
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Platelets (thrombocytes) are cell fragments essential for blood clotting (coagulation). When a blood vessel is damaged, platelets adhere to the site, release chemical signals to recruit more platelets, and provide surface for clotting factors to form fibrin mesh that traps blood cells to stop bleeding. RBCs carry oxygen; WBCs fight infection; plasma is the liquid medium.

Multiple choice

Red blood cells contain red pigment called _______.

  1. plasma

  2. platelet

  3. hemoglobin

  4. carbon-di-oxide
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hemoglobin is the red pigment found in red blood cells that gives blood its characteristic red color. It contains iron and binds to oxygen, allowing red blood cells to transport oxygen throughout the body. Plasma is the liquid portion of blood, platelets help with clotting, and carbon dioxide is a waste product transported by blood.

Multiple choice

Phagocytes and lymphocytes are the two types of _____.

  1. red blood cells

  2. white blood cells

  3. platelets

  4. plasma
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Phagocytes and lymphocytes are both types of white blood cells (leukocytes) that play crucial roles in the immune system. Phagocytes engulf and digest pathogens, while lymphocytes (including B and T cells) target specific threats. Red blood cells carry oxygen, platelets aid clotting, and plasma is the liquid portion.

Multiple choice

White blood cells which aid in resisting infections are called ____.

  1. leucocytes

  2. phagocytes

  3. melanocytes

  4. erythrocytes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Leucocytes (or leukocytes) is the scientific term for white blood cells, which are responsible for fighting infections in the body. While phagocytes are a specific type of white blood cell that engulf pathogens, leucocytes is the broader category. Erythrocytes are red blood cells, melanocytes produce skin pigment.

Multiple choice

Which of the following statements are false?

  1. All T cells originate from haematopoietic stem cells in the bone marrow.
  2. All the blood grouping reactions are precipitation reactions.
  3. Idiotypic determinants of an antibody are associated with the variable region.
  4. The basis for blue-white screening with PUC vectors is intergenic complementation.

  1. Only 1 and 2

  2. Only 1 and 4

  3. Only 2 and 3

  4. Only 2 and 4

  5. Only 3 and 4
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Correct answer. Both the statements are false. All the blood grouping reactions are agglutination reactions. The basis for blue-white screening with PUC vectors is intraallelic complementation.

Multiple choice

Which of the following cancers originate(s) in the bone marrow, develop(s) in the lymphatic system and normally fight(s) infection by producing antibodies?

  1. Chronic lymphoid leukemia
  2. Cutaneous T-cell lymphoma
  3. Intraocular melanoma

  1. Only 1

  2. Only 2

  3. Only 3

  4. Only 1 and 2

  5. Only 2 and 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This option is correct. Chronic lymphoid leukemia originates in the bone marrow, develops in the lymphatic system and normally fights infection by producing antibodies.

Multiple choice

Match the column – I (Proteins) with column – II (Immune system function).

 
Column – I Column – II
A. Alpha 2-macroglobulin 1. Inhibitor of fibrinolysis by inhibiting plasmin
B. Hepcidin 2. Induction of enzymes that degrade extracellular matrix
C. Serum amyloid A 3. Opsonin on microbes
D. C-reactive protein 4. Stimulates the internalisation of ferroportin

  1. A - 1, B - 2, C - 3, D - 4

  2. A - 1, B - 4, C - 2, D - 3

  3. A - 2, B - 4, C - 3, D - 1

  4. A - 2, B - 3, C - 4, D - 1

  5. A - 4, B - 1, C - 2, D - 3
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct. Alpha 2-macroglobulin - Inhibitor of fibrinolysis by inhibiting plasmin Hepcidin - Stimulates the internalisation of ferroportin Serum amyloid A - Induction of enzymes that degrade extracellular matrix C-reactive protein - Opsonin on microbes  

Multiple choice

What helps in clotting of blood in injured vessels?

  1. Platelets

  2. Lymphocyte

  3. Leucocyte

  4. Erythrocyte

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Platelets, also known as thrombocytes, are cell fragments that aggregate at the site of a wound to form a plug. They release chemicals that trigger the formation of a fibrin clot to stop bleeding. Erythrocytes carry oxygen, while leucocytes (including lymphocytes) are involved in immune responses.

Multiple choice

Thrombocytes is another name for _________.

  1. Red blood corpuscles

  2. Platelets

  3. Plasma

  4. White blood corpuscles

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Thrombocytes is the medical term for platelets, which are the components of blood involved in clotting. Red blood cells are called erythrocytes, and white blood cells are called leukocytes. Plasma is the liquid matrix in which these cells and fragments are suspended.

Multiple choice

The largest immunoglobulin is:

  1. IgA

  2. IgG

  3. IgM

  4. IgE
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

It is the largest Ig. It is a macroglobulin which is atleast five times larger than Ig G.